PSY201 Tutorial 5

According to the NHST approach, which of the following criteria must be met before we can run the post hoc analysis?

• The df value must be less than 1

• The F-ratio must be statistically significant

• Assumption of normality is met

• There must be only 3 levels of the IV

Wendy investigates if duration of exposure to sunlight can affect cognitive flexibility. All participants were exposed to 10 minutes of sunlight, followed by 30 minutes of sunlight. After each condition, Wendy assessed their cognitive flexibility using a special scale. She ran normality tests on the duration of sunlight exposure for each condition and then ran a repeated measures one-way ANOVA to test her hypothesis.

The testing of normality has a problem. Identify that problem.

• She ran normality on the IV levels instead of on the DV scores

• She ran normality for each condition instead of for everything as a whole

• Insufficient information provided

• There is actually no problem

What are X and Y?

• In-between; Split

• Within-subjects; Between-subjects

• Between-groups; Within-groups

• Between; Within

Janine ran an ANOVA, and the F-ratio in the output table was 1.45. What does this F-ratio mean?

• The unexplained variance is greater than the explained variance​

• F-ratio was not statistically significant

• The explained variance is greater than the unexplained variance

• Normality is assumed

What is the difference between methodological control and statistical control in experimental research?

• Methodological control: to statistically partial out effects of confounds

• Methodological control: to control confounding variables using design

• Statistical control: to control confounding variables using design

• Statistical control: to statistically partial out effects of ALL variables

Claire conducted a large scale study with 3000 participants. Which stats test should she run to examine the normality?

• Kolmogorov-Smirnov

• Shapiro-Wilk

• Welch's F

• Mauchly

Provide the definition for an interaction effect [besides “(combined) effect of both IVs on the DV”].

• When the changes in DV is dependent on the effect of IV

• When the changes in one DV is dependent on the changes in another DV

• When the effect of one IV is dependent on the levels of another IV

• When the effect of one IV is independent from the levels of another IV

Below are the variables in a study analyzed using factorial ANOVA:

§V1: Type of meditation (3 levels)

IV2:  Self-expression (2 levels)

SV3: Parenting Style (2 levels)

DV: Perfectionism

How many treatment conditions are there?

• 15

• 12

• 8

• 5

Define the homogeneity of regression slopes assumption.

• The regression lines of each condition all converge at least once

• Across all conditions, the relationship between DV and CV should be similar

• For each level of CV, the relationship between IV and DV should be similar

• The relationship between IV, CV, and DV has to be statistically significant

Which post hoc test should we refer to when the results from Levene’s Equality of Variances showed significance?

• Bonferroni

• Greenhouse-Geisser

• Huynh-Feldt

• Games-Howell