Stats for Psych Exam 4
what is eta between
0-1
for an experiment comparing more than two treatment conditions you should use ANOVA rather than separate T test because
ANOVA has a less risk of a type 1 error
A treatment effect refers to differences between scores that are caused by the different treatment conditions. The differences produced by treatment effects will contribute to
MS between
what is the formula for eta
SS between/ Sstotal
When do you use the cohen's D
after rejecting null hypothesis
what does it mean to fail to reject the null hypothesis
agree with the null hypothesis that there is no statistical difference
What are the two measures of measuring effect size
cohen's d and percentage of variance explained
what does between-treatment variance look at
differences between sample means
what does the difference score measure
differences between scores not individuals
When a research randomly selects equivalent groups, and then exposes them to different stimulus conditions, and then measures them to see if significant differences can be observed, the total procedure is an example of
experimental research
True or False for a repeated-measures design, a separate sample is used for each treatment condition
false
True or False when there are more than two treatments in an ANOVA. rejecting the null hypothesis means that all of the treatments were significantly different from each other
false
True or False, One disadvantage of a repeated-measures design is that it typically requires more subjects than an independent measures design
false
True or false, In an analysis of variance MS total will always equal the sum of MSbetween or MSwithin
false
true or false, Post hoc tests are used after analysis of variance to determine why the null hypothesis was not rejected
false
what does the percentage of variance measure (r^2)
how much variability in the scores is explained by independent variable
how does the repeated measures reduce the problem of large individual differences
increases variability
definition of a factor
independent variable or quasi independent variable
In an ANOVA, which of the following is most likely to produce a large value for the F-ratio
large mean of differences and small sample variance
what does within-treatment provide
measure of how much difference is reasonable to expect by chance
what does the repeated measures or within subjects design measure
measures the same group of subjects on dependent variable twice
What does Tuckys Post Hoc test tell us
minimum distance between treatment that is necessary for significance
If your HSD number is smaller then it is
not significant
what is a level (treatment)
number of conditions
in a difference score, what is the degrees of freedom based on
number of sample scores
what are the three assumptions for independent measures anova
observations are independent, populations were samples were selected must be normal and have equal variances
what is a one-way (single factor design)
only involves one factor
when is a difference score used
repeated samples t test
what does Tuckys Post Hoc Test require
same sample size
if your HSD number is larger then it is
significant
what is a sample
subset of a population
what does it mean to reject the null hypothesis
there is a statistical difference
what is a population
total amount of people in an area
What are the differences in a between-treatment variance caused by
treatment (I.V) and due chance
What does the cohen's d measure
treatment effects in terms of standard deviation
True or False basic analysis in ANOVA involves partitioning the total variability into two components: between-treatments variability and within treatments variability
true
True or False the critical region for the F-ratio from an analysis of variance is located entirely in one tail of the distribution
true
True or False when the null hypothesis is true, the F-ratio is balanced so that the numerator and denominator are both measuring the same sources of variances
true
True or False, For an experiment with k=3 treatments, MS between =10. For this analysis SS between equals 20.
true
True or False, When a study involves more than two treatment conditions, an ANOVA will evaluate all of the separate mean differences in a single test
true
True or False, repeated measures experiment reduce the variance contributed by individual differences
true
true or false, in a matched subjects test, the subjects characteristics are matched before the study begins
true
true or false, in an analysis of variance, the term factor refers to an independent variable
true
true or false, variance is always positive
true
what does the matched subjects design measure
two separate samples
In an analysis of variance, the F-ratio is a ratio of
two variances
What does the within-treatment variance look at
variability in each sample
independent variable
variable that is manipulated
dependent variable
variable that is measured
what is an Anova based on
variance
What is the f anova formula
variance between sample means / variance expected by chance
what is the formula for difference score
x2-x1