RM 2 exam 1 - reading charts
discussion - what's the nmnemonic
Run Little Doggy<br><br>--reverse funnel-small to large specfiic hypot<br>--different/simillar findings with theory/lit<br>--Limitations
discussion first points
Run Little Doggy<br><br>--reverse funnel-small to large specfiic hypot<br>--different/simillar findings with theory/lit<br>--Limitations
sum of squares and cross products
SSCP = the covariance for each pair of dv's
between groups SSCP total
SSCP total = Between/ within<br>--Between - group mean x grand mean<br>--Within = indvidual score/group mean = error
Univariate normality
Scores normal for<br>-each group(IV/level) for ANOVA
interpreting non signifigant results in terms of power
Sig results<br>--low power no sig = maybe not enough pt<br>---high power no sig = likely not there
Cohen's D<br>1 - start at 2 and go up to 5 then up to 8<br> .2 . 5 . 8 small medium large: Left off at 8<br><br>Step 2 ? <img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\keyboard.png">
Step 2: Count 8: Go down 1 to 5 = 85% overlap .2: Left off at 5<img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\colored keys.png">
step 3 metanalysis
Step 3 - coding - translate to # - best way to split not too broad to overlook and not to small<br><br>-probles and translate in by self<br>problems<br>did you capture the essential features?<br>missing data<br>acknowledge trouble and how impact future findgins<br>translate everything to quan<br>want general enough for gist, but specific enough to capture unique variable<br>report interrater relatibility for coding should be at least 80%
Step 4 cohen's after finding . 2 =85%, .5=67%, .8<img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\keyboard.png"><br>
Step 4: From 7 go over 1 to right & down 1 to = 5 : (box 2 complete)<br> From 5 go down again and over to the right = 3 (1/2 a rectanlgle complete)<br> .8 = 53% overlap<img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\colored keys.png">
test for sig of mean effect size - metaanysi
Stoffer method (f)<br><br>--convert to Z scores and add<br><br>compare to p value
homogeneity of covariance MANOVA
MANOVA -- use pilla's if violated, wilks if not<br>--homogeneity of covariance<br>--vectors of means = variance and normal distrubtion?<br><br>(all f)<br>variation between groups not = if violated<br><br>reduce power slightly when groups =<br>impacts power/type1 error
metanalysis vs research syntehiss - differences
META - > external validy and has fail safe N<br>RS -- not good for external validiy , no fail safe n
METAanalysis<br>IV
METAanalysis<br>IV<br>data that has been coded into categorical data often representing study features<br>remember you're analysis level is 1 up from regular bc your looking at study features and effect sizes (dv) not indvidual participants per se
SSCP matrix
Matrix with SS on diagnoals and SSCP for every DV pair filling the rest in<br><br>SS on diagnoal = the variance of each DV (f)<br><br>SSCP = the covariance for each pair of dv's (F)
Multiple ANOVA'S follow up analysis for sig multivarate effects alpha for sig and not
Multiple ANOVA'S protect type 1/experimental alpha when sig. If not sig use bonferoni<br>see debate: manova
nesting - just what is it. if yes and if no in seperately
Nesting<br>yes<br>are the same group of people giving the intervention for both groups or are they split<br>if nested finding could be result nonsepfic factors<br>no<br>random faciliators or mixing it up - nonspecfici factors wash out<br>makes it hard to keep IV seperate - you should always do MANIPULATION CHECK
Non-sig Q test
Non-sig Q test = good fit<br>homogeneity of effectshomogenity of distriubtions<br>homogeniety is good allows you to see IV is having effect not error<br>(f)means studies are from sampe pouplation and you can use group mean effects
f test which to use of the 4
Pilla's if homogeneity of variance violated<br>Wilk's if not<br><br>typically doesn't make much of a difference
metanalysis combine 1 study for effect size pro con
Pro<br><br>--each study doesn't get unfair extra weighting<br><br>- you control weighting for study qualities or whatever you want<br><br>downfall might obscure differences
Metanalysis mean effect
Quan DV metanalysis <br>indicate strength of assocation between study feature/outcome<br>standardized measure
anova manova debate - if manova not sig?
---some say if MANOVA not sig not protected use bonferoni
random vs fixed -- error ?
--Both<br>--error due to subject level sampling<br><br>Random<br>--error also due to study sampling
When you look at your alpha what 3 things do you need to remember that ti's associated with --confidence level & what does this mean
--I want to be 95% confident that I found my effect 1-.95= alpha .05, so if p = < .05 95% confident something happened. <br>so if you were to do the same study again, with a random selection from the same poulation you'd find simillar results with the similar chance of type 1 error as you did in your study
Mahalnous / Mahal's distance - <br><br>each pt deviation from centroid compared to cv which is compared to a critical value to check for outliersrs <br><br>Those that are sig = outlier , those that are not = not outlier <br><br>whatsa centroid
--centroid = pint created from remaining sample mean of all variables
unit of analysis - has to figure out how to combine dvs effect sizes to get mean effect -- difference for the 3 that deal with particular DV's
--each dv represented<br>-each concept represented<br>-each dv represented that youre interested in
Mahalnous / Mahal's distance - <br><br>each pt deviation from centroid compared to cv which is compared to a critical value to check for outliersrs <br><br>Those that are sig = outlier , those that are not = not outlier <br><br>So if some are signifigant what does it mean to you what should you do
--manova can do a few as long as there aren't too many or too extreme
Mahalnous / Mahal's distance - <br><br>each pt deviation from centroid compared to cv which is compared to a critical value to check for outliersrs <br><br>Those that are sig = outlier , those that are not = not outlier <br><br>where do you find the critical vlaue
-CV comes from MAhal's distance table - residula stats
/Multivariate normality -
-MANOVA- normal distribution for<br>--indvidual DV<br>--linear combo DV<br>-subset variables
why can't you intereptet well if your sample is hetrogenous - meatanlysi
-say your looking at med vs med and CBT and you find that med and cvt is hetrogenous -- well whats cuasing lower depression med or cbt <br><br>when hetrogenous = 2_ populations so u divide further or not interpret as well bc u don't know which populations are causing your eeffect
if you had N^2 .012 what would that mean<br>what about .14
.12 -- 1.2 % of the variance in our DV is explained by our IV<br>.14 -- 14% of the variance in our DV is explained by our IV
if you use a covariate that didn't meet assumptions
RESULT if not satifised group x covariate interaction that could be overlooked
step 1-3 metanalysis
1 hypot/research domain<br>2) lit review<br>3) coding<br>4) index es<br>5) analyzie ES<br>6) draw conclusions
steps 4-6 metanalysis
1 hypot/research domain<br>2) lit review<br>3) coding<br>4) index es<br>5) analyzie ES<br>6) draw conclusions
1 way
1 way MANOVA<br> 1 + categorical IV, 2 + continous DV's<br>iv<br>categrocial could be continous thats been chunked<br>Dv<br>DVS which are necessairly CORRELATED with each other and ideally theoeritcally correlated too <br>because it has 2+ dv = multiariate analysis<br><br>1 way anova - 1 iv 1 dv
covariate only ues if
1) stat correlated with DV(s)<br><br>2) homogeneity of reggression satisfied = relationship between covariate and dv must be = for all groups (f)<br><br>--RESULT if not satifised group x covariate interaction that could be overlooked (F)
covariate only use if correlated & --whats > homogeneity of reggression satisfied
1) stat correlated with DV(s)<br><br>2) homogeneity of reggression satisfied = relationship between covariate and dv must be = for all groups (f)<br><br>--RESULT if not satifised group x covariate interaction that could be overlooked (F)
2 way
2 way<br>manova could have a 2 way manova with 2 ivs and 2 + dvs<br>could have a 2 way manova with 2 ivs and 1 dv
When you look at your alpha what 3 things do you need to remember that ti's associated with --confidence level & what does this mean
<br>--I want to be 95% confident that I found my effect 1-.95= alpha .05, so if p = < .05 95% confident something happened. <br><br>so if you were to do the same study again, with a random selection from the same poulation you'd find simillar results with the similar chance of type 1 error as you did in your study
fiex effects model
<br>--error due to subject level sampling<br>--thinks underlyiging, united effect being measured<br>-hopes to generalzie to those like it<br>--think if sample sizes were large enough all effect sizes would be =
When you look at your alpha what 3 things do you need to remember that ti's associated with used to evalute p value
<br>--what level sig needed to reach to reject null<br> --how extreme socre needs to be to reject null
manova debate - criticism against hummel and sligo who said okay to do anovas after manova with out > experimenter wise alpha -- criticims point 2
<br>2) manova only protects type 1 error if null is true<br>so even if manova is sig doing anovas can still incrase experimterwise alpha
F test # groups need to compare
<br>3 +<br>Ratio of variance between groups/within groups<br><br>-stats test need 3 + groups to compare. like which age group runs fastest<br><br>--look at differences between groups --older kids run faster/<br>--look at diff within groups - could have a super fast 4 year old<br><br>Sig - difference between groups > within groups <br>= old kuds stiill run faster even if there are some oultliers
Run Little Doggy lats point
<br><br>--reverse funnel-small to large specfiic hypot<br>--different/simillar findings with theory/lit<br>--Limitations
unit of analysis - finding effect size for the whole study
<br><br>somtimes good bc each study isn't getting unfair weight but could obscure differences
anova manova debate - HUMMEL AND SLIGO
<br>ANOVA KEPT experimterwise lowest - didnt > it<br><br>looked at all diff ways to analyize manova <br>
between groups effect size
<br>Effect size = between / within<br>--between = SS between / between subject variance<br>--within = SStotal = error - so within has to look at indvidual scores to group means and group means tot tal mean for all
q stat specfically looks ay -- yes wants to see if you sample studies variation are representive of the poulation variation but how does it do this
<br>SSQ = between groups/ residual variability for q = within<br><br>then looks at distribution of effect sizes with chi square and u evalute with CV
When you look at your alpha what 3 things do you need to remember that ti's associated with -type 1 error
<br>chance type 1 error alpha .01 = 1/100 for every test<br>chance type 1 error for alpha .05 = 1 in 20 chances<br>out of the # of test you do in your sample or in the general population? -- general population if same poplulation, random sample same alpha
Step 3 - coding - translate to # - best way to split not too broad to overlook and not to small -problems
<br>did you capture the essential features?<br>missing data<br>acknowledge trouble and how impact future findgins
unit of analysis - finding effect sizefind effect sizes for each DV in 1 study<br>downfall
<br>downfall: # of dv's in 1 study could get unfair weighting
follow up analysis for sig multivarate effects - dv variable contiribution remove 1 variable at a time: technique Huberty : f to remove - test sig for each dv when removed from whole set<br><br>THEN?
<br>rank orders dv by impt
Step 3 - coding - translate to # - best way to split not too broad to overlook and not to small - translate everything to quan
<br>want general enough for gist, but specific enough to capture unique variable<br>report interrater relatibility for coding should be at least 80%
<img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\keyboard.png"> 1 - 2.5.8<br>2- .2 =85 % left off at 5<br>step 3: % overlap for . 5 = ?
<img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\colored keys.png"><br>--From 5 go over 1 = 6<br>--now go all the way left (4) and up 1 = 7<br>--.5 =67% - Box 1 completed and working on bottom of box 2
bonferoni inequeatility example for 6 test and nominal alpha .05
= 6 *.05 = 30% or less chance type 1 error for those 6 test <br><br>(f all under)<br>multiplies # of test and nominal alpha = max value of alpha for set of test<br><br>-used when manova NOT sig but still want to do ANOVA'S
MANOVA looks for diff between groups based on DV by looking at between groups/within groups<br><br>what goes into within groups groups?
= amt of error for all pt over GRAND MEAN<br><br>find with sscp<br><br>-- compares pt score to GROUP mean, then group mean scores to GRAND mean. <br><br>considers SSCP
within groups -- find it how what is it -- just find it
= error for all pt over grand mean<br><br>(found with SSCP total which looks at indvidual score to group mean, then gets you to group mean x grand mean)
within group manova
= error for all pt over grand mean<br><br>find with (f)<br><br>SCCP total - looks at indvidual scorex group mean
what to think of faciliators were nested
= good same group of people doing both intervention<br>ometimes hard to keep straight need manipulation check<br>washes out nonsepcfic factors
Mahalnous / Mahal's distance - <br>each person gets a deviation score from the centroid <br>which is compared to a critical value to check for outliersrs <br><br>Those that are sig = , those that are not =
> CV = outlier<br>< CV = not an outlire
publication bias
> effect sizes in published vs not published articles<br><br><br>--fail safe n helps but ntoes say bias can't be estimated or corrected for just compare studies
? She expect 4x - 4x / sd pooled effect what would negative tell you. ***********
? say 20 - 10 / 10 = outcome psychothreapy fan not good this d = + 1 tells you psychotherapy didn't do as well because their scores are on depression
cohens d . 8
? small = .2 or 85^ overlap between two distrubtions <br> ? moderate .5 67% overlap between two distrubtions<br> ? large - .8 or 53% overlap ..
F =
Ratio of variance between groups/within groups<br><br>(F)-stats test need 3 + groups to compare. like which age group runs fastest<br><br>--look at differences between groups --older kids run faster/<br>--look at diff within groups - could have a super fast 4 year old<br><br>Sig - difference between groups > within groups <br>= old kuds stiill run faster even if there are some oultliers
homogeneity of variance ANOVA
ANOVA - Levene's test<br>--homogeneity of variance<br>variance in test population = sample? homoschedastic<br><br>(all f)<br>variation between groups not = if violated<br><br> reduce power slightly when groups =<br>impacts power/type1 error<br>--if unequal = type 1 error up or down
familywise alpha/compairsonwise alpha
ANOVA ALPHA trouble<br>correct for how<br>lots of test like tukey, sheffe, least sig dfifference, newman - keuls, and duncans multiple range (not as impt)<br>chance of type 1 error within all test
DV - <br>in regards to test type
ANOVA<br>-1 dv<br>t test 1 dv<br>manova 2 + dvs that are correlated
manova assumptions
ASSUMPTIONS<br>indpencne of observations - nessary<br>okay if violated<br>homogeniety of covriance<br>look at box's m<br>use pilla's if violated, wilks if not<br>multivaraiate normality<br>sphericiphicity -- for repeated measures<br>dv's must be sig correlated with each other
metanalysis vs research syntehiss - similiarites
Both could do<br><br>divide studies into suuport hypot vs not<br><br>cant always guage effect sizes -- experimental could but could be hetrogenous so obscure<br><br>
Whats a linear compposite cannonical variable forumula?
CV = a or constant + w1v1 +w2v2+w3v3<br>- each in indviduallyuses<br>w = weight a weight for each DV per each IV<br>analogous to slope (rise/run)<br>higher scores have more weight meaning that that particular IV is discriminanting better<br>other names<br>discriminant function weight<br>discriminant function coefficent <br>a = discriminant function constant (y axis/intercept when making a line)<br>v - scores for each person on orginal DVs<br>example<br> CV = constant + .8 (v1) + .03 (v2)<br>v1 selective attention v 2 stm<br>v 1 = selective attention and it has the most weight meaning that it can tell the difference better for gender here - greater difference between the iv groups<br> her answer -- each group of IV's are weighted according to between group variability
linear question shows men and women differ most on selective attention vs stm (linear equation = a line)
CV = constant + .8 (v1) + .03 (v2) --- show that the weight is higher for the one we say has greater difference between groups. .. whats the weight called discriminant function. Variable 1 = selective attention more difference. V2 = stm
manova debate - criticism against hummel and sligo who said okay to do anovas after manova with out > experimenter wise alpha -- criticims point 1
Criticism<br>1) dat used in simulation not representive of real data<br>3) follow up ANOVAS ignore correlations between DVs<br>doesnt matter still > experimeter error<br>2) manova only protects type 1 error if null is true<br>so even if manova is sig doing anovas can still incrase experimterwise alpha
metanalysis - mnemonic
DICED<br>d- dispense knowledge<br>or whats most effective<br>i - identify effective variables<br>c - disadvantage can only compare post tx<br>e - examine effect sizes for ivs<br>draw conclusions<br>like if gap is in lit<br>summarize findings
DV - / criterion variable
DV - / criterion variable<br><br>t-test 1 continous DV<br>t - test<br><br>manova 2 + correlated dvs<br><br>anova- 1 continous dv<br><br>metanalysis<br>effect sizes from indvidual studies<br>remember you're analysis level is 1 up from regular bc your looking at study features and effect sizes (dv) not indvidual participants per se
Covariateimpact f 2 ways
F larger<br>--your IV had a larger impact than you thought that covariate was taking up too much variance<br><br>F smaller<br>--you're covariate seems to be really accounting for your impact
Introduction first two
FRIENDS FROM GPC :D <br>FRIENDS<br>Fill the gap<br>FROM<br> Funnel effect<br>G<br> Grounded in theory<br>P<br> Pertitent/Current literature<br>C<br> Conceputalize variables<br><br>FRIENDS FROM GPC :D <br><br>fftcc fftpc FFTPC
last three introduction
FRIENDS FROM GPC :D <br>grounded in theory<br>pertient.current literature<br>conceptualization of variables
phillai barlett trace - what it is
Good for<br>--small samples<br>unequal cell size<br>homogeneity of covariance<br>one of the strongest for protecting against type 1 with small samples
IV
IV --factor-- predictor<br>1 way 1 iv anova and manova<br>2 way 2 iv anova manova<br>t -test 1 iv 2 levels<br>metanalysis - no specificed # but usually decent amt unless your just comparing groups bc your looking at IVS<br>data that has been coded into categorical data often representing study features<br>remember you're analysis level is 1 up from regular bc your looking at study features and effect sizes (dv) not indvidual participants per se
MANOVA iv dv
IV/DV 1+ & 2 + continous DV's<br>it's an extension of the MANOVA<br>dv's must be sig correlated with each other
anova iv dv
IV/DV<br>Anova - 1 Way 1 Iv 3+ Lcategorical Levels & 1 Continous Dv<br>2way Anova 2: Iv's Categorical Ivs And 1 Continuous Dv
incrase power how and what is the result
Increase power - seat<br>>sample size<br>>effect size<br>>less stringent alpha<br>>1 tail<br>Results in > chance of type 1 error
step 4 meta anlyis :
Index ES - find mean effect by looking at effect sizes dv and variability - chose proper unit anayis within 1 study find effect size for 1 of these unis of aanlayss
Whats a linear compposite cannonical variable forumula? CV = a + w1v1 +w2v2+w3v3--whats v
Indvidual dependent variable scores for each person<br> DVsexample<br> CV = constant + .8 (v1) + .03 (v2)<br>v1 selective attention v 2 stm<br>v 1 = selective attention and it has the most weight meaning that it can tell the difference better for gender here - greater difference between the iv groups<br> her answer -- each group of IV's are weighted according to between group variability
Whats a linear compposite cannonical variable forumula? CV = a + w1v1 +w2v2+w3v3--whats w
It's the weight given to each DV as far as how well it discriminates between the IV's.<br><br>If you had .69stm +.2ltm then .69 would discrimainte between genders better than ltm
sum of squares
Variance = sum of squared eviations about a mean for each pt's score on each dv
purpose of linear composte/ cannonical variable
Weights = maxamize difference between groups<br>CV # used to look group differences<br>-accounted for correlation of DV
Whats a linear compposite cannonical variable forumula? CV = a + w1v1 +w2v2+w3v3--whats a
a = discriminant function constant (y axis/intercept when making a line)example<br> CV = constant + .8 (v1) + .03 (v2)<br>v1 selective attention v 2 stm<br>v 1 = selective attention and it has the most weight meaning that it can tell the difference better for gender here - greater difference between the iv groups<br> her answer -- each group of IV's are weighted according to between group variability
between subjects
a variable on which each subject can be found on only one level of the variable, such as age or gender
methods spasm A
a<br>answer choices
confidence interval (CI)
accounts for error and variation in effect sizes showing you <br><br>what range of scores,<br><br>that are distributed around the mean<br><br>could occur depending on alpha level set<br>--influnces probability<br>-- 95% confident your true value fall under<br>alpha .05<br>
additional assumptios mixed design
additional assumption homogeneity of intercorrelation (f)<br><br><br>pattern of intercorrelations should be the same for between and within subjects<br><br>test with box's m<br>but its senstive for this so use .01 in hopes u dont violate
assumption homogeneity of intercorrelation
additional assumption mixed design<br><br>pattern of intercorrelations should be the same for between and within subjects<br><br>test with box's m<br>but its senstive for this so use .01 in hopes u dont violate (f)
assumption homogeneity of intercorrelatio test how
additional assumption mixed design\<br><br>test with box's m<br>but its senstive for this so use .01 in hopes u dont violate<br><br>
q stat and goodness of fit
almost like a model of goodness of fit<br>bc you had to chose which unit of analysis to go with<br><br>(F) Non-sig Q test = good fit<br>homogeneity of effects<br>homogeniety is good allows you to see IV is having effect not error<br>means studies are from sampe pouplation and you can use group mean effects<br><br>(f)sig Q test = bad fit<br>hetrogeneity of effects<br>bad -- more error than IV having impact<br>means yur group of studies contains 2 + distinct subpopulations whicu should divide further<br>means you've got a lot of error and you'r iv in there
sum of cross-products**
amt of shared covariance between DVS<br><br>--so the variance for each subject variation from the mean on 1 DV & their variance on the other DV's and so on<br><br><br>variance - squared deviation from the mean<br>
homogenity of effects/distrubtion
are your mean effects/splts of iv = variability to poulation?<br><br>use Q for homogenity / hetrogenity<br><br>often people can't get full homogeniety<br>
assumptions anova
assumptions<br>necessary<br>indpendence of observcations<br>can still possibly be okay if violated<br>univariate normality<br>homogeniety of variance<br>look at levene's test if violated other wise no need to mention anything
what to think of faciliators were NOT nested
bad, <br>different groups of people doing different interventions<br><br>= results not as clear now = nonspecfic factors may be accounting for result<br><br> = confound - they might not realize/identify it & even if they do they might not measure it. <br>
within groups SSCP total
between looks at group means to grand means<br><br>so within has to look at indvidual scores to group means and group means tot tal mean for all
moderator vs interventing variable<br>
both started as confound where they <br><br>both share<br>identify measure<br><br>Moderator - accounted for <br>Intervneing variable (couldn't acount for it
Mean effect statistically sig??<br><br>
c<br><br>sometimes magnitude more interesting than stat sig (like if ci doesn't include 0)<br><br>need to know about characterstics of studies<br><br>they should translate it for you
phillai barlett trace - what it is caculates
caculates variance in DV accounted for by greatest seperation of IV<br>sum of explained variance on discrimiant varibles
weighted effects metanalysis
can weight your IV's based on sample size<br>--helps adjust for sampling error<br><br><br>--larger more weight bc better estimate of pouplation or maybe you choose study quality or both<br>
interaction effect
cell means going in different directions for each column?<br>if plotted would lines cross?<br>Means level of 1 iv impacting level in other iv
power
chance find sig result when it's really there<br><br>(f) -violate assumptions > alpha error < power<br>Homogeneity variance<br>--reduce power > alpha error if groups =<br>--if unequal = type 1 error up or down<br><br>(F) Sig results<br>--low power no sig = maybe not enough pt<br>---high power no sig = likely not there<br><br>(f) Increase power<br>>sample size<br>>effect size<br>>less stringent alpha<br>>1 tail<br>Results in > chance of type 1 error
MANOVA procedures looks at between within - elaborate on between
compares differences group mean and grand mean<br><br>produces single # = determinant<br><br>considering variance & covariance<br><br>the larger the # the more your IV had an effect
follow up analysis for sig multivarate effects -multivarate contrast / contrast analysis complex
complex contrast - can compare multiple groups of 2's in al combinations on DV<br><br><br>instead of using DV's this looks at IV's<br><br>comapres groups over set of dV simultaneously<br><br>simple/pairwise<br>-like huge t-test - 2 groups on combined DV can only compare 2 at a time<br><br><br>
step 5 step 5 - analyize ES distrubtion (MR for - requires
continous data<br><br>think 1+ sig predictor is found and u want to evalute which predictor is most impt<br><br>hierachiecial prefered - theory enter in order<br><br>simultaneous not liked as much
Covariate
continous variable<br><br>sig correlation with DV<br><br>used to<br>-factor out ANCOVA/MANCOVA<br>--look at for main interest<br><br>--impacts F 2 ways (f) <br>use only if -- (f)
covariance
covariance<br>the variation in one variable that is shared by another variable<br><br>Sum of Cross Products = sum of variance for one DV and sthe variance of another variable = index of covariance
2. what's a canonical variable? And how is it created.<br>1. HER ANSWER<br>
creates linear equatuon weights for each DV<br>each pt get score for that set of variables<br>. Greater the diff between the groups the larger the weight<br>
df
df<br>IV 4 groups (different climates) DV happy. n = 10 participants - repeated<br>f (3, 36) = 3.43 Wilks or Pilla's value, p <.05, ?2 = . 69 effect size<br>3, # = df<br> = # of groups -1<br>4 groups - 1 = 3<br>#, 6 = df<br>=( # groups * n) - total # of groups<br>4*10 - 4<br>note # of groups is 4 not 3
MANOVA looks for diff between groups based on DV by looking at between groups/within groups<br><br>what goes into between groups?
diff between group mean x grand mean - produces single # called dterminantn <br><br>larger # better IV
discriminant function coefficent
discriminant function coefficent <br>MANOVA finds a weight for each DV called a discriminant function coefficent . Computer does it . <br>Composite variable created using weights called a canonical variable = composite variable - makes them into 1 <br>see procedures combining dv manova
metanalysi mnemonic -- DICE full think ignore others
disementnaties knowledge<br><br>identifies impt variables, gaps and future research<br><br>conclusions drawn but limited to just post tx<br><br>effect sizes<br><br>
variance
dispersion of values around a mean<br><br>aVG of (mean - pt score)^2
q stat sig means what abou tpopulation
distinct subpopulations whicu should divide further<br>means you've got a lot of error and you'r iv in there
look at mean differences what do u do
divides all studies into 2+ groups based on IV thought to contribute to DV
follow up analysis for sig multivarate effects - dv variable contiribution remove 1 variable at a time: technique Wilkson's
do MANOVA'S with 1 DV left out at a time<br>- change in F score shows you which DV contributes the most<br>
follow up analysis for sig multivarate effects - dv variable contiribution 0 what does it do and what does it allow you to see
dv contributuon looks at decrease in multivareate effe as dvs are being taken out<br><br>shows: lets you see which DV contributes the most
dv contributuon while step down looks at
dv contributuon looks at decrease in multivareate effe as dvs are being taken out<br><br>while step down looks at effect while adding dvs with account for previous dv
cv is done for
each participant and each dv is weighted
Mahalnous / Mahal's distance - what does it do not what it means
each person gets a deviation score from the centroid <br>which is compared to a critical value to check for outliers
main effect
effect of single iv on dv<br>look at marginal means<br>--column 1 vs 2 on age --diff? main effect<br>--row 1 vs 2 on weight - diff ? main effect
how to interpret cohens d
effect size given in sd units like a z score<br>Interpreted In Sd Units - Like A Z Score<br> looks At Mean Differences<br>- Tells You How Different The Distrubtions Are From One Another Like Grousp Seperated By 1 Sd (F) <br> .2 small .5 medium .8 large<br>? small = .2 or 85^ overlap between two distrubtions <br> ? moderate .5 67% overlap between two distrubtions<br> ? large - .8 or 53% overlap ..
Cohen's D
effect size given in sd units like a z score<br>looks at mean differences<br>.2 small .5 medium .8 large<br><br>(f) to find = mean group 1 - mean group 2 / sd spooled<br>sd spooled is the avg sd for two groups
finding effect sizes in studies without means or SD
effect sizes can be caculated without means or sd for signifigant test
DV - / criterion variable metanalysis
effect sizes depending on how you split them<br><br>could just be (f)<br>1) each dv in the study<br>2) each construct in the study<br>3) the study as a whole<br>4 )combine your dvs like linear compsosite<br>--<br><br>
step 5 mean differences - if split wrong
errors if split wrong<br>say you looked at lumpectomy vs mastecoymy and find both - good<br>but then you take that same group and dvide them by family history finding an itneraction<br>if u find a diff u should use the new construct
alpha trouble for anova
experimeterwise -- looks at all of the test your doing to see chance type 1 error<br><br>Familywise/commonwise - looks at chance type 1 error for 1 test you run -more common in ANOVA<br><br>correct for: ike tukey, sheffe, least sig (f) dfifference, newman - keuls, and duncans
experimentwise alpha
experimeterwise -- looks at all of the test your doing to see chance type 1 error<br><br>bc comparing multiple levels of IV with DV
metanalysis typeexploratory
exploratory<br>uses standardzied group mean differences as the index of effect<br><br>-what relationsips between iv dv are supported
F test just what does it look at not the resulting F
f = within group variance/ total group variance = amt NOT EXPLAINED by DV (wilk's Pilla's)<br>effect size = 1 -wilks or ss between/ss total
file drawer problem
file drawer problem<br>the tendency for authors not to submit and journal editors not to accept for publication the results of experiments that fail to achieve statistically significant findings
random vs fixed -- undelrying theme
fixed - thinks underlying uniting theme - random doesn't
manova debate - criticism against hummel and sligo who said okay to do anovas after manova with out > experimenter wise alpha -- criticims point 3<br>
follow up ANOVAS ignore correlations between DVs<br>doesnt matter still > experimeter error
What's a linear composite / cannonical varriable
formula that combines all dvs into one while weighting ivs taht discriminate the best'(f) all in indvidually after here<br><br>formula - done for each person<br> CV = a + w1v1 +w2v2+w3v3<br>uses<br>w = higher the weight the more the DV discriminates between groups IV -- <br>analogous to slope (rise/run)<br>higher scores have more weight meaning that that particular IV is discriminanting better<br>other names<br>discriminant function weight<br>discriminant function coefficent <br>a = discriminant function constant (y axis/intercept when making a line)<br>v - scores for each person on orginal DVs<br>example<br> CV = constant + .8 (v1) + .03 (v2)<br>v1 selective attention v 2 stm<br>v 1 = selective attention and it has the most weight meaning that it can tell the difference better for gender here - greater difference between the iv groups<br> her answer -- each group of IV's are weighted according to between group variability
inferential stats follow...
genreal linear modelline y = a +b (x) b slope, a y intercept x = data point not really what we're doing just as example
inclusion exclusion critiera - part of step 2 metanalysis review<br><br>randomized vs not : randomized
gold standard<br>- random assignment = > internal validity < external validity bc strict inclusion/exclusion critiera <br>
Wilk's looks for differences where
group means<br><br>type of F test<br><br>used when homogeneity of variance not violated MANOVA<br><br>looks at within group variance/total group variance<br><br>1- Wilks = effect size (between/within)<br>--so the smaller the wilks the larger the effect size<br><br>Looks for differences in group means<br>
test homogeneity of effects
homogeneity of effect sizes with Q<br>sort of like testing for homogeneity of variance - is it error or IV?<br>procedure<br> by looking at SSQ = q between groups / residual variability Q qithin<br>looks at distribution of effeft sizes for group of studies like a chiq squrae variable with # of studies -1 = df<br>use critical value to find sig result needed
one of the requirements for using a covariate relationship between covariate and dv must be = for all groups<br>-- what is it
homogeneity of regression
additional assumption for follow up after manova step down
homogeneity of regression - impt to look at if you do a step down analysis
criticismmetaanlysis
how know u splt right - might compare apples to oranges<br><br>--accounting for differences in studies<br><br>metanalysis never better than the indvidual studies that comprise them
adjusted (or unbiased) effect<br>
if have < 30<br>use adjusted effect which reduces effect size
if mixed design sig interaction
if it was sig you would have to be super careful interperitng main effect bc interaction = impact of 1 influenced by other so general conclusions like main effect might not be approriate<br>pic<br>pic<br>no interaction between program type and time wilks .87, f =2.03 p.15
confidence interval how to know if sig
if range doesnt include 0 <br> --ES of .45 has a CI ranging from .20 to .70), then the mean ES is considered to be statistically different from zero
box m and levene's test if it's sig = if its not sig =
if sig your bad<br>if it's nto sig ogod didn't violate homogeniety of variance<br>
so dvs need to be correlated for MANOVA whats too high and too low what should u do
if they aren't correlated consider seperate anovas for DV's<br>if too highly correlated = multicolineary - happens like if one variable is a combo of your other variables = singularity<br>just do a correlation matix. if abocve .8 or .9 bad
step 2 can't be totally comprehenisive lit review - fail safe n
impossible to be totally comphrensive - file draw/publicatoin bias<br>use fail safe n<br>there is no aboslute standard for assessing what value of the fale safe n is critical<br> do fail safe n after data analysized<br>estimates the # of additional studies that would have to be located to change your result
which is the only assumption that is really bad if you violated
independence of observation - DON'T VIOLATE<br><br>multivariate normality homogeneity variance, repeated sphericity ok
MANOVA procedures looks at between within - elaborate on within
indvidual scores compared to their group's mean<br><br>error<br><br>variance & covariance<br><br>Between: diff between group x vs total mean
each study should contribute at least 1 effect size if u just do 2+
indvidual studies dvs are often correllated so when u include more than 1 effect size your not accounting for overlap which results in overweighting of study<br>if you think some of measures in single study represent diff constructs that are idnepent of one another then it might be okay to d o more than 1 effect size
chi-square (x2)
inferental stat<br>can transform into <br>probbility level
follow up analysis for sig multivarate effects -multivarate contrast / contrast analysis
instead of using DV's this looks at IV's<br><br>comapres groups over set of dV simultaneously<br><br>simple/pairwise (F)<br>-like huge t-test - 2 groups on combined DV can only compare 2 at a time<br><br>(f)<br>complex contrast - can compare multiple groups of 2's in al combinations on DV<br><br>
interaction effect
interaction effect<br>1 iv influences the other<br>you'd want your cell means for each column going in opposite directions<br>-looking at cell means not marginal means<br>if lines eventually corss = interaction<br>1 main effect an an interaction<br>pic<br>pic<br>explanation<br>main effect<br> you want 1 simillar and 1 dissimillar marginal mean<br>6 & 5.5 arent that diff from one another but 7 and 4.5 are<br>interaction<br>you'd want your cell means for each column going in opposite directions<br>when u look down the yound colum # get smaller, down the old > larger = interaction<br>you can do a simple effects analysis - see simple effects<br>be careful to remember that if you have sig interaction and you only have 2 levels for one of your IVS you have to look at descriptives, post hoc is for 3 + levels of IV
Expresses mean effect as r would be appropriate when
iv's dvs are contonous<br>
iv dv metaanylis
iv/dv<br>IV<br>data that has been coded into categorical data often representing study features<br>DV<br>(F)effect sizes from indvidual studies<br>remember you're analysis level is 1 up from regular bc your looking at study features and effect sizes (dv) not indvidual participants per se
iv dv other named mixed between subject anova
iv: 2(Cog, Behavioral) x 2 (time period scores on fear)<br><br>dv fear scores<br><br><br>split plot anova SPANOVA
When you look at your alpha what 3 things do you need to remember that ti's associated with
just list top categories - rest in (f)<br><br>used to evalute p<br>uses confidence intervals<br>assocaited with type 1 error
follow up analysis for sig multivarate effects -multivarate contrast / contrast simple/pairwise
like huge t-test - 2 groups on combined DV can only compare 2 at a time<br><br>instead of using DV's this looks at IV's<br><br>comapres groups over set of dV simultaneously<br><br>simple/pairwise<br>-like huge t-test - 2 groups on combined DV can only compare 2 at a time<br><br>complex contrast - can compare multiple groups of 2's in al combinations on DV<br><br>
step 2manova which 3 must u do
lit review - coms search, manua serac, review references - use fail safe n - not use 3 and you could miss something
looking at mean differences step5
looking at mean differences<br>divides all studies into 2+ groups based on IV thought to contribute to DV<br>Controversy on how to split<br>no way to know you grouped right<br>making to broad of categories is bad<br>bc maybe the iv should have been split to see difference bc some other variable accounting<br>errors if split wrong<br>say you looked at lumpectomy vs mastecoymy and find both - good<br>but then you take that same group and dvide them by family history finding an itneraction<br>if u find a diff u should use the new construct
procedures Manova for F
looks at SSCp/between and SSCp within<br>Between - <br> compares group mean and grand mean<br>produces single # = determinant<br>considering variance & covariance<br>the larger the # the more your IV had an effect<br> within (F)<br> looks at indviduals score compared to their group mean<br>considering variance & covariance<br>= error<br>cacculate F to find effect size (f)<br>f = within group variance/ total group variance = amt NOT EXPLAINED by DV (wilk's Pilla's)<br>effect size = 1 -wilks or ss between/ss total
follow up analysis for sig multivarate effects stepdown analysis
looks at effect while adding dvs with account for previous dv<br><br>get to see unique contribution<br><br>order put in is impt - need causal logical order<br><br>(f)<br>dv contributuon looks at decrease in multivareate effe as dvs are being taken out<br><br>while step down looks at effect while adding dvs with account for previous dv<br><br>-assumption homogeniety of regresion
doubly multivariate repreated measure manova
looks at mean differences across levels of IV so u can see pre/post test effects<br><br>so time is one of the ivs
procedure ANOVA
looks at means and mean differences to find out how much your IV worked (to see how much total variation is expalined by your maniupliation) you<br>look at the DIFFERENCE<br>BETWEEN GROUPS<br>attributed to your iv maniuplation<br> looks at group mean compared to grand mean<br>divided by<br> WITHIN GROUPS<br>attributed to natural error<br>compares indviduals score to their group mean
manova assumption: multivareate normality - check for with mahalnovus diance -- Wha'ts it basically doing?
looks at the variation of each persons score<br><br> from the remaining samples mean <br><br>to check for outliers
method spasMs
m<br>measures your using, incude demographics and recrutiment
purpose
manova/anova - stat DIFFERENT between groups? main effects/interactions? for DV or composite DV<br><br>t-test groups stat DIFFERENT from each other?<br><br>metanalysis (f)<br>summarize research findings shows u what eveyone else is finding<br>impt technique allowing u to draw conclsuons / dissementate knoweldge<br>public poicy implaictions<br>can identify effective programs and highlight gaps limitations in research
follow up analysis for sig multivarate effects -discrimintant analysis
maxamize seperation between groups on IV with linear composite<br><br>you're basically doing a linear composite for each signifigant effect<br><br>get to see subsets of construct for which groups differ
metanalysis<br>types
metanalysis<br>types<br>exploratory<br><br>descriptive<br><br>treatment effectivness<br>
coding
method by which study features (types of subjects contro group etc) tranformed into quant iv for the stat analysis coding yield combo continous variable for study features like # of med sx and categorical variability respresetning other featur want > 80% interereater realibilit yes like meds meds + cbt
mixed design
mixed design<br>looks at between and within variables
roy's largest root bad or not suitable for
multiple dimensions<br>if it's sig and others aren't then it's ignored bc it shows the upper bound of F
bonferroni inequality - what does it do and why would you need it
multiplies # of test and nominal alpha = max value of alpha/type 1 error for set of test<br><br>-used when manova NOT sig but still want to do ANOVA'S<br><br>example (f)<br>true alpha = example for 6 test and nominal alpha .05<br> = 6 *.05 = 30% or less chance type 1 error for those 6 test
step 2 metanalysis -
must do all 3 ) coms serach, manula search, review of reference<br>-- need to consdier fail safe n
n vs N metanalysi
n in metanalysis refers to # of stuides revieed<br> where N =# subjects unless noted otherwise
What's independence of observations
necessary condition - not in indvidually<br>pt score on DV not influenced by other group <br>don't want 1 level of your IV or another IV influenced by the other<br>find out how<br>use an interclass correlation<br>if correlated what does it mean<br> actual alpha can raise up to 7x nominal level even for a little correlation<br>for manova<br>if violated<br>use group means instead of indvidual scores in your analysis
step 5 mean differences - controversy how to split
no way to know you grouped right<br>making to broad of categories is bad<br>bc maybe the iv should have been split to see difference bc some other variable accounting
types of alphas
nominal - what you set<br> actual - what really occurs<br> experimenterwise - anova/manova etc- type 1 error chance for all test<br> familywise/common wise -- type 1 error for 1 test you run in the family
cohens d score range
not limited to | 1|
inclusion exclusion critiera - part of step 2 metanalysis review<br><br>randomized vs not : not randomized
not randomly assigned - possible more external validity since randomized often stric inclusion/exclusion critiera<br>oulation
not sig q- good homogenity g - now what
not sig q- good homogenity g can more clearly see IV effect<br>examing mean effects is apporpriate
nonsig box m and levene
not<br>non sig Box's m = didn't violated assumption of homogeniety of vovariance- use wilks<br>Levene's violated assumption of homogeneity of variance - just not it
null hypothesis H0
null hypothesis H0<br>the hypothesis that states that there is no difference in the mean values of one or more DVs across levels of one or more IVs<br>MANOVA<br>no differences between groups/vectors of means for groups<br>the people who created hope you'd do a random sample so it'd be population means difference = 0 but we use samples so its we expect no difference between group means/vectors of means<br>anova considers indvidual means to look at differences<br>repeated designs consider mean differences
random effects mdoel
often this model is used<br><br>--random error due to <br><br>subject level sampling<br>study level sampling<br><br>doesn't propose single underlying effect size assumes randomly distributed with averages being represted
effect size interpretation large small metaanlysis
often we think the larger effect size the better but not always the case = here a small effect shows that they were close together which is good for psychotherapy
omnibus test
omnibus test<br>a test of the null hypothesis that none of the IVs has an effect on any of the DVs<br>omnibus test<br>test the null hypot<br>can refer to diff test like<br>ANOVA F test - between groups/repeated measures<br>multiple regression<br>chi squaresa<br>more likely to hapeen when testing overall hypothetsis on quadratic statistic (looks at vectors, variance etc.) / maybe > likely with multivariate test<br>types<br>Family: Omnibus test: \<br>"a test statistic to which multivariate indices can be transformed, to derive a probability levle."<br>AKA looks = between group variance / within group variance <br>Large F = > between = IV had desired effect<br>example<br>say design with 1 iv and 3 dvs<br>--If you did an ANOVA you'd have to do 3 of them bc you only can do 1 DV @ a time > error<br>-- MANOVA = just 1 dig omnibus test (F) with the all those DV's turned into a composite variabe < error in compairson to ANOVA<br>USED IN<br>used in: MANOVA (1+ categorical IV & 2 + continous DV)<br> & ANOVA (1 or 2+ categorical IVS's & 1 continous DV)
SS
on diagnoal = the variance of each DV
confound vs moderator
once was a confound but now<br>identified<br>measured<br>accounted for<br>---(f) if you couldn't account for it then it's an intervening variable as like as the other conditions are met (identified, measured)
moderator what is it
once was a confound but now<br>identified<br>measured<br>accounted for<br>if you couldn't account for it then it's an intervening variable as like as the other conditions are met (identified, measured)
unit of analysis - when deciding on which IV's to include you need to decide how you're going to combine those DV's for the IVs your interested in..what are your options
option A<br>--1 effect size per study<br><br>option b - Multiple effect sizes per study<br>--all dv's in one study<br>--each construct presentedi n 1 study<br>--each dv that you're interested is represtented in the study
outlier
outlier<br>an extreme value in a distribution of effects. authors should specify how an outlier is defined. even tho outliers are excluded from eventual analyses so as not to distort the findings, they should be inspected for their heuristic value: outliers might suggest particularly successful or unsuccessful programs
methods spams P
p<br>procedures<br>proper headings?
one of the strongest for protecting against type 1 with small samples
pilla's
p value
probability level<br>--you're result occured by chance<br><br>-shows you how extreme you're scores are based of your sample.<br><br>smaller the p more like iv
COHEN'S D can only comare
prupose: allows you compare ONLY 2 GROUPS
anova purpose
purpose<br>Lets You Look At Main Effects, Interactions<br>Groups Sig Different From Each Other?<br>do post hoc to see where differences are<br>Anova Test For Effect Sizes By Looking At Ss Between / Ss Within
manova purpose
purpose<br>can look at main effects and interactions<br>have to do post hoc to see where exact differences are<br>manova test the differences between groups based on the cannonical/linear composite variable <br> diff between subjects SSCP- between<br>/ within SSCP subjects<br>looks at vectors of means while accounting for correlation in DV
purposed mixed design
purpose<br>whether there a re main effects for iv's and an itneraction
have to test for what before analysizing effet sizes metaanlysis
q sta required before analyzie - no one gets perfect but can't interpret as well if <br><br>f -variability in effect sizes for the studies you're looking at compared to the poulation<br><br>f non sig= homogenous - studies/divisons variation = population<br><br>f sig = hetrogenous - samples/divisons = 2+ population - divide further or can't interert as confidently bc you don't know which of the populations is causing your effect
effect size r
r by itself (f)<br>?effect size same as eta <.9 small, .9-2.35 medium <br>tells u strength, direction,
r^2
r^2 effect size<br>% of varriance accounted for<br>r by itself (f)<br>?effect size same as eta <.9 small, .9-2.35 medium <br>tells u strength, direction,
random vs fixed - think what about their sample studie effecy sizes?
random: --think obtained effect sizes represent avg falling on nomral bell curve<br><br><br>fixed think if sample sizes were large enough all effect sizes would be =
if homogeneity of variance is violated what happens (yes I know u know the Wilk's pilla's thing tell more)
reduce power slightly when groups =<br>impacts power/type1 error<br>--if unequal = type 1 error up or down
repeated measures
repeated measures<br> see assumptions manova/anova<br>repeated designs consider mean differences<br>see - doubly multivariate repreated measure manova<br>an experimental design and corresponding analysis in which each subject is measured on the DV for more than one level of an IV (eg. time 1 and time 2) / repeated measures<br>an experimental design and corresponding analysis in which each subject is measured on the DV for more than one level of an IV (eg. time 1 and time 2)
homogeneity of regression
requirements of covariate <br> relationship between covariate and dv must be = for all groups<br>
anova manova procedue
same procedures except manova looks at variance and covariance and anova just looks at variance<br>looks at SSCp/between and SSCp within<br>Between - <br> compares group mean and grand mean<br>produces single # = determinant<br>considering variance & covariance<br>the larger the # the more your IV had an effect<br> within<br> looks at indviduals score compared to their group mean<br>considering variance & covariance<br>= error
Follow up analysis manova choices<br>SC
scam<br>-step down<br>-(dv) Contribution <br>-Anovas or discriminant analysis<br>-multivarate contrast
Follow up analysis manova choices<br>mnemonic
scam<br>-step down<br>-(dv) Contribution <br>-Anovas or discriminant analysis<br>-multivarate contrast
Follow up analysis manova choices<br>scAM
scam<br>-step down<br>-(dv) Contribution <br>-Anovas or discriminant analysis<br>-multivarate contrast
Sig q hetrogeneity bad- what do u do
sig - hetrogeneity bad- your catching error and iv effect and u've got 2 populations - divide further<br>try to idenitfy variability contributing to hetrogeniety
Result of Q non sig
sig Q test = bad fit<br>hetrogeneity of effects<br>means yur group of studies contains 2 + distinct subpopulations whicu should divide further<br>your sample is hetrogenous<br>stat sig q<br>you've got 2+ populations in your sample - yoou need to split futher<br>means you've got a lot of error and you'r iv in there<br>bad - / you're sample is homogenous<br>homogeniety is good allows you to see IV is having effect not error<br>means studies are from sampe pouplation and you can use group mean effects<br>varaibility around effect size is no greater than you'd expect from error good fit 0- ths is what u want
sig Q tes
sig Q test = bad fit<br>hetrogeneity of effectshomogenity of distriubtions<br>bad -- more error than IV having impact<br>means yur group of studies contains 2 + (f) distinct subpopulations whicu should divide further<br>means you've got a lot of error and you'r iv in there
sig> meta
sig><br>magnitude of effecct can can be sometimes more interesting thatn stat sig (wehther CI includes 0)<br>practical sig<br>depends on several factors<br>stat mag not related to practical impt<br>impt to know charactersitics of otucome measure in which es based<br>they should translate it for u
Univariate/Multivariate normality -what happens if violated
small impact type 1<br>< power by flatening bell curve<br><br>- people still run test<br>
method mncmeonic
spasms<br> suitable for current sample <br>procedure/proper heading<br>answer choices<br>sample# questions<br>measures used, demographics, recruitment<br>scoring
Method mnemonic
spasms<br>s<br>scoring<br>p<br>procedures<br>proper headings?<br>a<br>answer choices<br>s<br>suitability for current sample/ realiability of scale<br>validity is a bonus<br>m<br>measures your using, incude demographics and recrutiment<br>s<br>sample item # questions
stanadrized scores
stanadrized scores<br>z<br>d<br># units away from the mean<br>see effect sizes cohens d
Expresses mean effect how? & consideration of scale of measurement - Cohen's d
standard deviation units so you can compare and combine<br>not limited to | 1 | though most fall within this range<br><br>Cohens d- for 2 groups only (F)<br>r - for continous variables<br>x^2 for dichotomous variables
what ways can you express mean effect--------- and what considerations should u use for your variables (F)
standard deviation units so you can compare and combine<br>not limited to | 1 | though most fall within this range<br><br>Cohens d- for 2 groups only (F)<br>r - for continous variables<br>x^2 for dichotomous variables
Cohen's D 0 first step to find # and what they mean<img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\keyboard.png">
start at 2 and go up to 5 then up to 8<br> .2 . 5 . 8 small medium large: Left off at 8<br><img src="c:\users\chelsey\dropbox\current classes\flashcards for all classes\classes\research\research stats\colored keys.png">
statistical signfigance
statistical signfigance<br>?compaare p and alpha<br>?p = < alpha = reject null yay!<br>?P = > alpha = boo nothing found<br>?smaller the alpha the harder it is to get statistical significance<br>anova/manova bigger differences between groups than within
step 1 metanalysis
step 1 - hypot and research domain<br>formulate hypot<br>clearly define relevant research domain
step 4 metanlaysis
step 4: Index ES - find mean effect by looking at effect sizes dv and variability - chose proper unit anayis
step 5 meta
step 5 - analyize ES distrubtion (MR for continous data -heirachical better) (Mean difference catgeorical)
step 6 draw conclusions - meta anlsysis
step 6 draw conclusions<br>offer suggestions specific to the lit you evaluted consistent with database limitations<br>offer reccomendations improve future research - useful indicate hwo study artificats in studies could have impacted current findings
non siqn q means what about poulation and generalizability
studies are from sampe pouplation and you can use group mean effects - > generliaze
study artificats
study artificats<br>any error or bias in studies- always assess in conclusions/interpretations
methods spaSms
suitable for popualtion<br>sample item<br>scoring # questions<br><br>
sum of cross products
sum of cross-products = covariance<br> sum of variance for one DV and sthe variance of another variable = index of covariance<br>find sd for each person (indvidual score deviation/grand mean)
metanalysis typedescriptive
summarize<br><br>broad<br><br>doesnt consider implications / draw conclusuions
q staistic looks @
test like homogeneity of variance -- is the variance from systematic differences or sampling error<br>(f sall below) by looking at SSQ = q between groups / residual variability Q qithin<br>looks at distribution of effeft sizes for group of studies like a chiq squrae variable with # of studies -1 = df<br>use critical value to find sig result needed
Stoffer method
test mean effect sig (f)<br><br>--convert to Z scores and add<br><br>compare to p value
determinant
the single # that is produced for a numerator and denominator when looking @ b/w diff
<br>effect sizes show you
the strength between iv/dv
moderator variable theoretically
theoretically studies with diff level of same moderate should differ in effect size
what kind of variables are usaully moderators
those that are unmaniplated like ses
how to find cohens d
to find = mean group 1 - mean group 2 / sd spooled<br>sd spooled is the avg sd for two groups
total group variance
to find the overall total group variance for all DVS for between/within on MANOVA<br><br>look at SSCP total which compares indvidual scores to group mean
metanalysis typetreatment effectivness
treatment effectivness<br>impact of tx type questions framed in realtive terms<br>like does a help b better than nothing at all
alpha trouble familywise correct for how
tukey<br>sheeff <br>duncan<br>kehuls
type 2 error
type 2 error<br>accepting the null hypothesis when it is really false
roys largest root<br><br>looks at and as a result - good
type of F test looking at <br>largest eignvalue<br><br>if u have a single dimension & strong correlations > power specificity
hotellings lawel trace T^2<br>type purpse
type of F test<br><br>2 groups compared on linear composite<br><br>= most sig linear combination of the DV for 2 groups
Wilk's
type of F test<br><br>used when homogeneity of variance not violated MANOVA<br><br>looks at within group variance/total group variance<br><br>1- Wilks = effect size (between/within)<br>--so the smaller the wilks the larger the effect size<br><br>Looks for differences in group means (f)<br>
simple effects
type of analysis done for signifigant interactions on ANOVA. <br><br>you do anova's across and if sig t test down
types anova
types<br>1 way<br>ANOVA - 1 way 1 IV 3+ lcategorical levels & 1 continous dv<br>2 way<br>2way anova 2: IV's categorical IVS and 1 continuous DV<br>REPEATED<br>ANCOVA
types of metanalysis
types<br>exploratory<br>descriptive<br>treatment effectivness
types of manova
types<br>mancova<br>doubly repeated measures manova<br>2 way<br>1 way<br>manova
follow up analysis for sig multivarate effects - dv variable contiribution remove 1 variable at a time: technique Huberty
use F to remove statisic for each DV<br>then test sig of decrease when removed from entire set<br>rank orders dv by impt
x^2 chi square Expresses mean effect how? & consideration of scale of measurement
used when iv/dv dichotomous result chi square
CV = constant + .8 (v1) + .03 (v2)<br>v1 selective attention v 2 stm whats this mean?
v 1 = selective attention and it has the most weight meaning that it can tell the difference better for gender here - greater difference between the iv groups<br> her answer -- each group of IV's are weighted according to between group variability
SD variability unit of metaanlaysis
variability allows you to see how much IV working<br><br>ES .05 sd<br><br>= 98% of all effects range between -.5 and 2.5
homogeneity-heterogeneity<br>
variability distrubtion of ESS for group of studies<br><br>just sampling error variance = homogenous-good<br><br>hetrogenoug = sample error and IV = bad
moderator variable
variable accounts for sig variability in effect size<br>theoretically studies with diff level of same moderate should differ in effect size<br>Usually exist when the variable is unmanipulated.<br>like ses or degree<br><br>relationship to confound/intervening variable (F)
q compares variability in what to what
variaiblity in effect sizes for studies/ivs you haave created compared to the poulation
sphericity assumption<br>Violation =
variance in all differences between all combo's of related groups isn't =<br><br>required for repeated manova<br>test for with maulchys test of sphereicity<br><br>> type 1 error
between groups
variation accounted for by IV<br><br>(f) SSCP total = between/within<br>where between looks at difference between group mean x grand mean<br><br>(F) Effect sizes = between/within<br>where between = SS between/between subject variance
Homogeneity of variance (anova) or covariance (manova - just general information
variation between groups not = if violated<br><br>(F) reduce power slightly when groups =<br>--if unequal = type 1 error up or down<br><br>(f) MANOVA -- use pilla's if violated, wilks if not<br>--homogeneity of covariance<br>--vectors of means = variance and normal distrubtion?<br><br>(f) ANOVA - Levene's test<br>--homogeneity of variance<br>variance in test population = sample? homoschedastic
weight etaalysis
weights<br>each study often has dif sample sizes<br>larger sample size better estimate of poulation than small so need to consider sample size when avg by weighting each effect size<br>you could also weight by other impt indices like by quality of study
within subject
within subject<br>an IV used in such a way that DV values are obtained for every level of the within subject variable
type 1 error
yay i found it ./.. but not really there
metanalysis - you'll be looking at diff types of effect sizes in each study so what do u do
you can combine them since they are standardized<br><br>even if different types like cohens or R
homogenity of distriubtions - METAANLYSIS
you want to make sure the varaince in your sample/way ou parced it for IVS is = to the poulation<br>use q stat<br><br>homo good