Complex Experimental Methods

Question 1

interaction effect

Answer 1

effect of one independent variable depends on the level of another independent variable

IV1 depends on IV2

Question 2

factorial design

Answer 2

testing more than one IV at a time allows us to test for interactions

• studies with two or more IV (also referred to as factors)

Question 3

full factorial design

Answer 3

levels of IV 1 x levels of IV 2 = all possible combos

Question 4

factorial notation

Answer 4

3 x 2 x 2

how many numbers are there? = # of IVs
what do each numbers represent = levels of IV
what does the product of the factors tell us? # of conditions

Question 5

participant variables

Answer 5

IV that is non-manipulated
- variables are selected and measured abut not manipulated (e.g age)

IV 1
on cell phone vs not on phone

IV 2 (participant variable)
younger drivers vs older drivers

Question 6

definition of main effect

Answer 6

is there an overall difference?
the overall effect of one IV on the dependent variable, averaging over the levels of the other IV

Question 7

main effect calculations (table)

Answer 7

calculation
IV 1
level 1 level 2
IV 2 level 1 1 2 avg 1
level 2 3 4 avg 2
avg 1 avg 2
1. compare averages to see which IV has more of an effect on DV
2. subtract averages to see the difference between the IVs

how does IV 1 and IV 2 affect DV?

example answer: on average people who were alone (M = 9) reacted 3 minutes faster than people who were with strangers

difference in averages

Question 8

defintion of interaction (table)

Answer 8

the effect of factor A on the DV depend on the level of factor B

• sign of results matter

how is IV 1 influenced by IV 2 ?

                                  temp
                      hot            cold food  hb         10                   2          8
     icesk       4                   10        -6
                     6                   -8 the effect of food is different based on temperature

the effect is temperature is different based on food
difference in differences

Question 9

main effects in graphs

Answer 9

y

                              x x-axis: compare averages vertically  y-axis: compare averages horizontally

Question 10

questions to ask while figuring out main effect

Answer 10

1. what is the IV?
2. what are the levels of the IV
3. what are the averages of each IV
4. compare averages to determine main effect on DV

Question 11

interactions for graphs

Answer 11

parallel = no interaction
non-parallel = interaction

Question 12

interpreting interaction results

Answer 12

1. compare endpoints vertially and horizontally then subtract
2. the difference indicates difference in each interaction

same as what you would do in graphs

Question 13

main effects for bar graphs

Answer 13

x - axis IV = compare middle
y - axis IV = compare height of bars with same color

Question 14

interactions for bar graphs

Answer 14

method 1: do the differences between bar heights change as you go across x - axis?

method 2: connect the tops of the corresponding bars. would those lines be parallel?
not parallel = interaction
parallel = no interaction

Question 15

between subjects factorial design

Answer 15

• all of the factors are manipulated between subjects
• each subject participants in just ONE condition

Question 16

within subjects factorial design

Answer 16

• all of the factors are manipulated within subjects
• each subject participates in ALL conditions

Question 17

mixed factorial design

Answer 17

• some of the factors are manipulated between subject, some within subjects
• each subject participates in more than one, but not all conditions

tip: go through each IV/levels and indicate which are between, which are within subjects to ensure that it is the mixed factorial design

Question 18

factor a x factor b, how many main effects and interactions are there?

Answer 18

2 main effects (A & B)
1 interaction ( A x B)

Question 19

factor a x factor b x factor c, how many main effects and interactions are there?

Answer 19

3 main effects (A & B & C)
4 interactions (A x B, A x C, B x C, A x B, C)

Question 20

how many participants are in a between subjects, within subjects, and mixed subjects?