chapter 12: factorial experimental designs

Question 1

factorial design

Answer 1

groups are created by manipulating the levels of two or more factors and

different participants are observed in each group using experimental procedures of randomization (for between-subjects factor)

OR same participants observed in each group using control for timing and order effects

Question 2

why factorial design?

Answer 2

Many effects in nature are conditional or depend on other factors

builds on previous research

control for threats to validity (including threats as IVs)

analyze the effects of two or more factors simultaneously + their interactions

Question 3

between-subjects factorial design

Answer 3

must - manipulate the levels of each IV, cross the levels of the 2 IVs to create the groups, use random assignment, compare group differences in DV

ex// consumption:
IV1 - visibility of food (2 levels - visible vs not visible)
manipulate - place food in open bowl or closed bowl

IV2 - proximity of food (2 levels - near, far)
manipulate - place bown in arms reach or 2 meters away

4 groups:
10 particpants who experienced near + visible, 10 for near + not visible, 10 for far + visible, 10 for far + not visible (40 participants total) (MEASURING AMOUNT CONSUMED)

Question 4

within-subjects factorial design

Answer 4

must - manipulate the levels of each IV, cross the levels of the 2 IVs to create the groups, control for order effects, compare group differences in DV

ex// consumption:
IV1 - visibility of food (2 levels - visible vs not visible)
manipulate - place food in open bowl or closed bowl

IV2 - proximity of food (2 levels - near, far)
manipulate - place bown in arms reach or 2 meters away

4 groups:
10 particpants who experienced near + visible, same for near + not visible, same for far + visible, same for far + not visible (10 participants total) (MEASURING AMOUNT CONSUMED)

Question 5

mixed factorial design

Answer 5

different participants are observed at each level of a between-subjects factor and repeatedly observed across the levels of the within-subjects factor

must - manipulate levels of each factor, cross the levels of each factor to create groups, randomly assign different participants to each level of BTSB IV, control for order effects

ex// attention to warning label
IV1 (within-subjects) - WARNING TYPE (2 levels - text only, text + image)
manipulate by showing warning w text and then w text/image

IV2 (between-subjects) - PACKAGE STYLE (2 levels - plain, branded)
manipulate by either showing participants plain package style or brand package style

2 groups:
10 participants who experienced the PLAIN packaging + text-only warning then text/image warning AND a different 10 participants who experienced BRANDED packaging + text-only warning then text/image warning (20 PARTICIPANTS TOTAL)