Psychology Research Methods: Chapter 9 Multi-Group Design and ANOVA

What is nonexperimental design?

A design with no manipulation of the independent variable (IV) and no examination of cause-and-effect relationships.

What is experimental design?

A research method where the experimenter controls and manipulates the IV to establish cause-and-effect relationships.

What is a two-group design?

An experimental design that compares two groups or conditions to establish cause and effect.

What is multi-group design?

An experimental design that involves three or more groups.

What is one benefit of multi-group design?

It allows comparison of two or more treatments or levels of treatment.

How does multi-group design save time?

It enables running a single study that compares multiple groups instead of multiple two-group studies.

What type of relationships can multi-group design uncover?

Nonlinear relationships that may not be evident with just two comparison groups.

What is a confound?

A variable that the researcher unintentionally varies along with the manipulation.

What is a placebo group?

A group where participants believe they are receiving treatment, but they are not.

What is an empty control group?

A group that does not receive any treatment and is measured on the dependent variable.

What does methodological pluralism refer to?

The use of multiple methods or strategies to answer a research question.

What is one-way ANOVA?

A statistical test that determines if responses from different conditions are essentially the same or if at least one condition differs.

What is the null hypothesis (H0) in one-way ANOVA?

µ₁ = µ₂ = µ₃ .... = µk, indicating no difference between group means.

What is the alternative hypothesis (H1) in one-way ANOVA?

At least one group mean (µi) is different from the others.

What are post-hoc comparisons?

Examinations of all possible combinations of conditions statistically, after the study has been conducted.

What is the Tukey's HSD method used for?

A post-hoc comparison method to evaluate differences between group means.

What is the Bonferroni method?

A correction method used for both post-hoc and planned comparisons to control for Type I error.

What is the Scheffe method?

A post-hoc comparison method that allows for complex comparisons between groups.

How is a statistically significant difference reported in APA format?

As determined by one-way ANOVA (F(2,27) = 4.47, p = .021, η2 = .27).

What does the chi-square test of independence examine?

Whether the distribution of participants across categories is different from what would happen if there were no differences.

How is a significant association reported in APA format for chi-square tests?

There is no significant association between variables as determined by chi-square test of independence (χ2(1, N = 80) = 0.49, p = .485, Φ = .08).