two way ANOVA

Question 1

interaction effect

Answer 1

whether the effect of the original independent variable depends on the level of another independent variable. “a difference in differences”

Question 2

What is the mathematical way to describe an interaction of two independent variables?

Answer 2

There is a difference in differences. ex: the difference between the cell phone and control conditions might be different for older drivers than younger driver

Question 3

spreading interaction

Answer 3

a situation where the effect of one independent variable significantly changes depending on the level of the other independent variable, but only at one level of that second variable, while showing a relatively consistent effect at the other level. ex: saying sandwiches taste better when you add either bacon or avadcado and ESPECIALLY good when you add both. adding avacado when you already had bacon leads to a large increase in deliciousness. (difference in differences)

Question 4

factorial design

Answer 4

there are 2 or more independent variables

Question 5

whats another word for conditions?

Answer 5

cells

Question 6

participant variable

Answer 6

a variable whose levels are selected (measured) not manipulated ex: age

Question 7

are variables such as age, gender, and ethnicity truly independent variables?

Answer 7

no but researchers often call them independent variables for the sake of simplicity

Question 8

What is one reason why researchers conduct studies with factorial designs?

Answer 8

to test whether an independent variable affects different kinds of people or people in different situations in the same way

Question 9

moderators

Answer 9

an independent variable that changes the relationship between another independent variable and a dependent variable. results in an interaction

Question 10

why would researchers use factorial designs?

Answer 10

to test the generalizability for a causal variable but also to test theories a form of external validity and interactions show moderators

Question 11

In a 2-way anova, what is there?

Answer 11

2 main effects and one interaction effect

Question 12

main effect

Answer 12

the overall effect of one independent variable on the dependent variable, averaging over the levels of the other independent variable “is there an overall difference”

Question 13

marginal means

Answer 13

each level of the independent variable averaging over levels of the other independent variable. The averages of rows and columns

Question 14

If the sample size in each cell is exactly equal, how do you calculate the marginal mean?

Answer 14

taking a simple average

Question 15

when there is both an interaction effect and main effect, which is more important?

Answer 15

interaction

Question 16

What happens to the number of interactions when a factorial design has 3 or more independent variables?

Answer 16

the number of interactions increases to include all possible combinations of the independent variables

Question 17

how do you write out main effect statements?

Answer 17

“There is a main effect for training type such that the vocabulary-training group scored higher than the no-training group.”

“There is no main effect for test type.”

when describing a main effect only mention one type ex: vocab training vs no vocab training, math vs verbal. math and verbal wasnt in the above statement when writing the statement for math and verbal dont include training type

Question 18

what do we use for 2 way ANOVA

Answer 18

line and bar graph

Question 19

what do parallel line graph and bar graph lines mean?

Answer 19

probably no interaction

Question 20

independent groups factorial (between subjects factorial)

Answer 20

Both IVs are manipulated between groups. If the design is a 2 x 2, there are four different groups of participants; for example. If you wanted 50 participants in each cell, then you would need 200 participants total (50 in each of the four groups).

Question 21

which is more efficient between groups factorial or within?

Answer 21

within
For example, if you wanted 50 participants in each cell, you would only need 50 participants total because each of those 50 people would be in each of the four conditions.

Question 22

mixed factorial design

Answer 22

One IV is manipulated as independent-groups and the other is manipulated within-groups.

This design is intermediate between the within-groups design and the independent-groups design in terms of number of participants.

ex: In a 2 x 2 mixed factorial design with 50 people in each cell, you would need 100 participants, which is twice as many participants as a within-groups design and half as many as an independent-groups design

Question 23

how are factorial notated

Answer 23

Factorials are notated like this: ___ x ___. The number of blanks tells you the number of IVs, and the numbers that you put in the blanks tells you the number of levels of each of the IVs.

Question 24

how are interactions most likely detected?

Answer 24

with a line graph to see whether the lines are parallel.

Question 25

3-way design is a what

Answer 25

2 x 2 x 2 Factorial Design (3 possible 2 way interactions)

Question 26

where in an empirical journal article will you find info about the study design

Answer 26

The Method section will describe the design of the study.
Factorial notation: _____ x _____ x _____

Question 27

what does the results section of an journal article tell you?

Answer 27

The Results section will examine whether the main effects and interactions were significant.

Question 28

what phrases are used in an article to highlight an interaction

Answer 28

“it depends” and “only when” and participant variables (e.g., age, gender, ethnicity).