Stats Anova
ANOVA is an ________ test
Omnibus
Three characteristics of a One-Way ANOVA
One IV, One DV, Three or more levels of the IV
MS equation
SS/df
individual score from groups score
SSe
Individual difference, measurement wrrot
SSe (Sum of Squares Error)
Individual score from total mean
SSt
Variability among all scores on the DV
SSt
What is F?
Test statistic for ANOVA
k=
number of groups
How is F calculated?
MSb/MSe (Between group variance/Error Variance(MS))
4 Assumptions to complete the one-way between-subjects ANOVA
Normality Random Sampling Independence Homogeneity of Variance
more than one IV and DV
Factorial MANOVA
Why wouldn't you use separate t-test for more than two levels of the IV?
It would increase the Type 1 error to something above 5%
A one-way within-subjects ANOVA is typically associated with _____ power than the one-way between-subjects ANOVA.
Larger
The effect of the IV
SSb (Sum of Squares Between)
What is the typical effect size used with ANOVA?
SSb/SSt
The post hoc test controls against making what type of error?
Type 1, keeps alpha at 0.05
The same participants are measured in each level of the IV
Within-Subjects ANOVA
For the one-way within-subjects ANOVA, the more ________ participant responding between groups, the less powerful the test will be at detecting the effect
inconsistent
Without changing the value of error variance, the _________ between-groups variability, the more likely we are to reject the null hypothesis.
larger
The term "between-subjects" refers to A. Observing different participants one time in each group B. The type of post hoc conducted C. The type of effect size estimate measured D. Observing the same participants in each group
A
T/F As mean square error decreases, power decreases
False
A researcher measures anxiety levels among participants in the presence and absence of a fearful stimulus. If the same participants are observed in each group, then what type of statistical design is appropriate for this study? A. Related-Samples t test B. A one-way between-subjects C. A one-way within-subjects D. both A&C
D
The turkey HSD post hoc test only works for what?
Equal group sizes
F
MSb/MSe
T/F To conduct a one-way between-subjects ANOVA, we assume that the samples were randomly selected from populations with equal variances, and that participants were independently observed in each group.
True
If the experiment is successful...
then the model will explain more variance than it can't (SSb will be greater than SSe)
ANOVA stands for...
analysis of variance
For an analysis of variance, the term "one-way" refers to.. A. The number of statistical tests in the design B. The number of factors in the design C. The direction that traffic should follow on a road D. The number of ways that the data can be analyzed.
B
Homogeneity of variance is an assumption for the one-way between-subjects ANOVA. What does this assumption mean? A. That the population being sampled from is normally distributed B. That the variance is equal in each population from which samples are selected C. That one observation has no effect on the likelihood of another observation D. That participants are randomly selected to participate in a sample
B
A researcher divides participants into groups that will engage in low, moderate, or intense levels of exercise. The total calories consumed by participants following the exercise are then recorded. What type of statistical design is appropriate for the study? A. Related-Samples t test B. A two-independent sample t-test C. A one-way between subjects ANOVA D. Both B&C
C
Computing a one-way between-subjects ANOVA is appropriate when A. the levels of one or more factors are manipulated B. The same participants are observed in each of two or more groups for one factor C. Different participants are observed one time in each of two or ore groups for one factor D. all of these
C
Computing a one-way within-subjects ANOVA is appropriate when A. different participants are assigned to each group B. the levels of one or more IV are manipulated C. The same participants are observed across groups D. All of these
C
T/F A post hoc test is only necessary following a decision to retain the null hypothesis
False
Group mean from the total mean
SSb
The term "one way" means that you are testing...
one factor
F=
t^2
3 reasons why ANOVA is omnibus
1. Tests for overall difference 2. Tell us the group means are different 3. Doesn't tell us exactly which means differ
The source of variability associated with error variance in the one-way between-subjects ANOVA is called... A. Within-groups variability B. Between-groups variability C. Degrees of freedom D. both A&B
A
Post hoc tests are computed A. prior to conducting a hypothesis test B. following a significant ANOVA test to make pairwise comparisons C. To determine which set of degrees of freedom can be attributed to the variability between groups D. To determine if groups means differ, even for tests in which decision is to retain the null hypothesis
B
There are two sources of variation in a one-way between-subjects ANOVA: one attributed to differences between groups and one attributed to error. T/F
True
more than one DV
one-way MANOVA
Used when different participants are measured in each level of the IV
one-way between subjects
T/F An ANOVA is used when samples are selected from two or more populations and when two or more samples are selected from the same population.
True
How many sources of error are present in a one-way within subjects ANOVA?
2
A researcher compares differences in positivity between participants in a low-, middle-, or upper middle-class family. If she observes 15 participants in each group, then what the degrees of freedom for the one0way between subjects ANOVA?
2, 42
Which of the following is an assumption for computing a one-way between-subjects ANOVA? -One observation has no effect on the likelihood of another observation -Participants were selected to participate using a random procedure -The population being sampled from is normally distributed -All of the above
All of the above
"Within subjects" is also called... A. Random Sampling B. Repeated Measures C. Within-groups D. Between-subjects
B
Anova with 2 IV's
Two-way ANOVA
Following a significant one-way between subjects ANOVA in which k > 2, what is the next appropriate step? A. interpret the data; no further tests are required B. Summarize the data; no further tests are required C. Conduct post hoc tests D. both A&B
C