module 2 Flashcards
(16 cards)
What is the primary goal of comparing groups in research?
To determine whether observed differences between groups are meaningful or occurred by chance.
What does Null Hypothesis Significance Testing (NHST) assess?
The probability that observed differences occurred by chance if the null hypothesis were true.
What is the purpose of a t-test?
To determine if there is a significant difference between the means of two groups.
When is an independent-samples t-test used?
When two experimental conditions involve different participants in each group.
When is a paired-samples t-test used?
When the same participants are tested in both conditions (repeated measures).
What are the assumptions of an independent-samples t-test?
A: Interval/ratio DV, random sampling, normality, and homogeneity of variance.
What are the assumptions of a repeated-measures t-test?
Interval/ratio DV, random sampling, and normality.
What does the t-statistic represent?
A: The ratio of the mean difference to the standard error; it tests whether the group means are significantly different.
What is the formula for the t-statistic in an independent-samples t-test?
(Mean₁ - Mean₂) / Standard Error
Why not use multiple t-tests instead of ANOVA when comparing more than two groups?
Multiple t-tests increase the familywise error rate, raising the chance of a Type I error.
What is the purpose of a one-way ANOVA?
To determine if there are any statistically significant differences between the means of three or more groups.
What does the F-statistic in ANOVA represent?
The ratio of variance between groups to variance within groups.
What are the null and alternative hypotheses in a one-way ANOVA?
H₀: μ₁ = μ₂ = μ₃ = … = μₖ
H₁: At least one group mean is different.
What does a significant F-statistic tell us?
That at least one group is significantly different from the others, but not which specific group(s).
What are the three types of variance in ANOVA?
Total variance (SSTotal), variance between groups (SSBetween), and variance within groups (SSWithin).
What is the formula for the F-statistic?
F = Variance between groups / Variance within groups
