ANOVA

Consider a cognitive psychologist who studies memory. The psychologist is interested in state dependent learning--where people remember information better when they are asked to recall it in the same place where they learned it. This psychologist is also interested in whether the complexity of this information affects recall. So she uses a context manipulation (same, different) and asks participants to recall information that varies in complexity (low, high). She uses a between subjects design, fully crossing all conditions. Consider the cells with these names: A (Same Context, Low Complexity) B (Same Context, High Complexity) C (Different Context, Low Complexity) D (Different Context, High Complexity) Which cells would you compare to find the interaction if you were interested in whether the effect of complexity differed across context?

(A vs. B) vs. (C vs. D)

Consider a cognitive psychologist who studies memory. The psychologist is interested in state dependent learning--where people remember information better when they are asked to recall it in the same place where they learned it. This psychologist is also interested in whether the complexity of this information affects recall. So she uses a context manipulation (same, different) and asks participants to recall information that varies in complexity (low, high). She uses a between subjects design, fully crossing all conditions. Consider the cells with these names: A (Same Context, Low Complexity) B (Same Context, High Complexity) C (Different Context, Low Complexity) D (Different Context, High Complexity) Which cells would you compare to find the interaction if you were interested in whether the effect of context differed across complexity?

(A vs. C) vs. (B vs. D)

A1. A2 B1. 2. 4 B2 4. 2

1. For the following question, treat the numbers in the table below as the cell means from a Factorial Anova. Examine these means and identify which effects are present. Assume ANY difference between numbers is statistically significant. -Interaction 2. For the following question, treat the numbers in the table below as the cell means from a Factorial Anova. Examine these means and identify which effects are present. Assume ANY difference between numbers is statistically significant. -Two main effects + an interaction 3. For the following question, treat the numbers in the table below as the cell means from a Factorial Anova. Examine these means and identify which effects are present. Assume ANY difference between numbers is statistically significant. -Two main effects, no interaction

Consider a cognitive psychologist who studies memory. The psychologist is interested in state dependent learning--where people remember information better when they are asked to recall it in the same place where they learned it. This psychologist is also interested in whether the complexity of this information affects recall. So she uses a context manipulation (same, different) and asks participants to recall information that varies in complexity (low, high). She uses a between subjects design, fully crossing all conditions. Consider the cells with these names: A (Same Context, Low Complexity) B (Same Context, High Complexity) C (Different Context, Low Complexity) D (Different Context, High Complexity) Which cells would you compare to find the main effect of context?

A&B vs. C&D

Consider a cognitive psychologist who studies memory. The psychologist is interested in state dependent learning--where people remember information better when they are asked to recall it in the same place where they learned it. This psychologist is also interested in whether the complexity of this information affects recall. So she uses a context manipulation (same, different) and asks participants to recall information that varies in complexity (low, high). She uses a between subjects design, fully crossing all conditions. Consider the cells with these names: A (Same Context, Low Complexity) B (Same Context, High Complexity) C (Different Context, Low Complexity) D (Different Context, High Complexity) Which cells would you compare to find the main effect of complexity?

A&C vs. B&D

A contrast test is helpful after finding a significant F value because: a. it controls for subjects who happen to be in more than one condition b. it can tell us if there is a difference between two individual groups c. it looks to see if the variance is more than we would attribute to chance d. A contrast test assumes the curve is normal whereas an ANVOA does not.

It can tell us if there is a difference between two individual groups

The ANOVA is superior to using multiple t-tests because:

It keeps the alpha level set at a known low rate.

Consider an example of a research studying three ways of teaching. She wants to know if groups who receive these teaching methods differ. What are possible reasons why variance might exist between the group means?

The types of teaching methods being used in the study & The number of groups in the study

Consider a cognitive psychologist who studies memory. The psychologist is interested in state dependent learning--where people remember information better when they are asked to recall it in the same place where they learned it. This psychologist is also interested in whether the complexity of this information affects recall. So she uses a context manipulation (same, different) and asks participants to recall information that varies in complexity (low, high). She uses a between subjects design, fully crossing all conditions. How many cells are in this design?

four

Why does being an omnibus test give an ANOVA a disadvantage?

it doesn't reveal the location of differences between groups

Which of the following is NOT true of an F test?

it is unimodal it is not symmetrical ->it is bell-shaped<- its value is always positive

What is the most common number on an F distribution?

one

A one-way ANOVA has been performed to compare the means of 3 groups and a significant F was obtained. At this point, we would:

reject the null hypothesis

A one way ANOVA has been performed to compare the means of 4 groups and a significant F was not obtained. At this point, which of the following options would be most appropriate:

retain the null hypothesis