Concepts
Why do we need to perform post-hoc tests after finding a significant main effect?
What is-
It does not specify which
means/groups were different.
What is this saying?
A one-way ANOVA with F(3, 218) = 2.89, p = .036.
(answer: we will work through this)
What is the null hypothesis for an ANOVA
What is all groups are equal
As the sample size increases, chi-square distributions begin to look like this.
What is a normal distribution?
This statistical assumption is violated when one condition’s data spread is very different from the others.
What is sphericity?
A study investigates the effect of two types of therapy (cognitive vs.behavioral) and therapy duration (2 weeks vs. 2 months) on anxiety reduction. Participants are randomly assigned to either cognitive or behavioral therapy and to one of the two durations.
What are the independent variables? What are the levels of each variable?
IV1: Type of therapy (2 levels: cognitive vs. behavioral)
IV2: Duration of therapy (2 levels: 2 weeks vs. 2 months).
Using a stronger manipulation increases this part of the F-ratio
What is the numerator
I have a chi-square test with a sample of 456 of scores from a standard normal distribution, square each score, and find SS. How many degrees of freedom does the chi-square distribution have?
df= 456
The effect of one IV at a single level of another IV
What is a simple effect?
Got to slide for the problem.
https://docs.google.com/presentation/d/1BJHDHfZFoi88sSPl0FJbXabIaf8UTIUzUtyFHJ75vfE/edit?usp=sharing
We will go over this
If the null is true, the F-statistic should be close to this number.
What is 1
A correction to the chi-square statistic is sometimes used when you have a contingency table with...
What is an expected cell frequency that is below 5
The degrees of freedom for the main effect of grade level in a 4×2 design
What is 3
Participants complete a problem-solving test under three stress conditions (low, moderate, high) while wearing either noise-canceling headphones, regular headphones, or no headphones. Each participant experiences only one stress condition but all headphone conditions.
Mixed design
To find the MSB/MSE what do you divide on the table?
What is the SS/DF
The Chi Square distribution shows the probability of _____, depending on the # of samples drawn from a normal distribution
the sums of squares
This row in a within-subjects ANOVA represents how much the condition effect differs by participant.
What are the within-subject residuals
Slides
Answer
A between-subjects experiment compared five groups of people. If the SSQ condition for the main effect of Group was 100, what was the MSB?
100/3= 33.3
What does the chi-Square distribution do?
The chi-square distribution shows the probability for
different sums of squares when sampling condition scores from a z-distribution.