PSYC 363 Exam 3 Lecture 14/15-ANOVA & 16- Research Cycle

What is a factorial design?

• Any study involving more than one independent variable (IV) simultaneously.

What is the main effect?

represents the impact of one independent variable on the dependent variable, regardless of the values of the other independent variables.

Interaction

Occurs when the effect of one IV depends on the specific level of another IV.

Simple Main Effect

•  Breaking down an interaction by examining the effect of one IV at a specific level of another.

What is the likely statistical outcome when lines on a line graph are parallel?

It indicates that there are no interaction effects present.

What if they’re intersecting?

• Suggests a likely interaction effect.

What if they’re neither parallel nor intersecting? (hint: think about main effects and interaction) -

• It is an ordinal interaction; an interaction effect will be present 

What does ANOVA stand for? -

• Analysis of Variance. 

How is the F statistic calculated? (no need to know the specific formula, just the general idea) -

What are the factors affecting how large F is?

• Smaller within-group variability, larger between-group difference

What is a one-way ANOVA? -

• 1 Independent Variable, 3+ levels.

What is the advantage of a one-way ANOVA over independent-samples t-test? -

Its ability to compare the means of three or more groups simultaneously without increasing the risk of a Type I error (false positive). It maintains the overall significance level whereas multiple t-tests increase the error rate.

What is a two-way ANOVA? -

•  2+ IVs (factorial design)

What does each digit in a factorial design represent? What does the actual number represent? -

(2×3) 2= Two independent variables, two levels (ex: male, female)..

The second IV has three levels (ex: low, medium high)

What is repeated-measures ANOVA? -

• a statistical test used to compare the means of three or more measurements taken from the same subjects over time or under different conditions.

What is a regression? How is it calculated (general idea, not specific formula)

•  used to predict an outcome (dependent variable) based on one or more predictor variables (independent variables).

What is chi-square? What research questions is it suitable for?

•  determines if there is a significant relationship between two categorical variables (e.g., gender and political affiliation) by comparing observed frequencies to expected frequencies.

  • Suitable for surveys and categorical research questions

One-sample t-test:

• a statistical method used to determine if the average (mean) of a single group differs significantly from a known or hypothesized population value.

Independent-sample t-test:

• compares the averages (means) of two completely separate, unrelated groups to determine if they are significantly different from each other.

Paired samples t-test:

• compares the averages (means) of two completely separate, unrelated groups to determine if they are significantly different from each other.

Correlation

• Strength of the relationship between two continuous variables.

What are the different components (sections) of a research article?

• Abstract, Introduction, Methods, Results, Discussion, References, and Tables and Figures.

How is the introduction section of a research paper organized?

• Define specific hypotheses, define what is known and what is needed to be found out from the study, and lastly understand why this topic is important. 

• How is the discussion section organized? - 

• Restating the hypotheses, support with personal research data alongside other literature sources, and broader implications.

What is publication bias? -

• The tendency to publish only research that shows significant effects.

  • Example: gender differences.

What are some of the major national research funding agencies? -

• National Institutes of Health (NIH), National Science Foundation (NSF), Ford Foundation, Spencer Foundation, William T. Grant Foundation, Bill & Melinda Gates Foundation.