Factorial Designs

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Factorial Designs
Research Methods Part III Lecture 19
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Outline

• Factorial designs
• Basics
• Varieties of factorial designs
• Mixed designs
• P x E designs
• Examples of factorial designs
• Imagery and memory
• Sleeper effect
• Marital status and perceived attractiveness of
  potential dating partners

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Basics of Factorial Designs

• factorial designs more than one independent
  variable
• notation
• e.g.
• 2 x 2
• 3 x 4
• 2 x 2 x 2

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Factorial Designs

• 2 x 2 design
• between vs. within subjects designs
• sample size

Factor B
B1
B2
A1
Factor A
A2
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Factorial Designs

• 3 x 4 design

Factor B
B1
B2
B3
B4
A1
Factor A
A2
A3
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Factorial Designs

• 2 x 2 x 2 design

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Schachter Singer (1962)

• 2-factor theory of emotion

No emotional change
No emotional change
Feel happy
Feel angry
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Ekmans display rule

• Cultural differences in emotional expression
• Display rules (Ekman Friesen, 1975)

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Ekmans display rule

• Cultural differences in emotional expression
• Display rules (Ekman Friesen, 1975)

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Attractiveness and Legal Judgment 40 judges and
1500 court cases involving misdemeanor cases
40 judges 1500 court cases
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Varieties of Factorial Designs

• Mixed designs
• between-subjects design within-subject design
• P x E designs
• subject variable manipulated variable

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Mixed Designs

• basic structure

Group 1
Condition2
Condition1
Group 2
Condition1
Condition2
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Which one do you like more?
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Mixed Designs - Example

• Mere exposure effect (Zajonc, 1968)
• familiarity breeds fondness
• one of the reasons why proximity promote liking

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Mixed Designs - Example

• Mita, Dermer, Knight (1977)

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Mixed Designs Size of sample

• less number of subjects

Self
Picture image
Mirror image
Friends
Picture image
Mirror image
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P x E designs

• Person x Environment designs
• subject variable x manipulated variable
• popular in research on the effectiveness of
  psychotherapy and personality
• interested in an interaction between person x
  situation
• less than a true experiment

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P x E designs Example

• Holmes, McGilley, Houston (1984)
• Subject variable
• Type A personality
• Type B personality

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P x E designs - Example

• Holmes, McGilley, Houston (1984)
• Subject variable
• Type A personality
• Type B personality
• Manipulated variable
• difficulty of task (digit span memory)
• 3 levels (3 different length easy, moderate,
  difficult)
• Dependent variable
• systolic blood pressure

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Results
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Factorial designs Examples

• Memory and imagery (Wollen, Weber, Lowry, 1972)
• the effect of visual imagery on memory
• nature of imagery normal vs. bizarre
• combination of images interacting or not
• 2 x 2 design
• word pair study (e.g., piano cigar)

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Imagery and Memory
Bizarreness factor
Normal
Bizarre
Yes
Interaction
No
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Imagery and Memory
Bizarreness
Bizarre
Normal
Overall
Yes
Interaction
No
Overall
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Imagery and Memory
combination
recall
No combination
Normal
Bizarre
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Factorial Designs Example 2

• Sleeper effect (Pratkanis et. al., 1988)
• the impact of a persuasive message increases
  over time, when it is accompanied by a
  discounting cue
• e.g., negative political advertising
• why it works?
• the link between the message and the discounting
  cue gets weaker over time

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Example 2 - Sleeper effect
Discounting cue
Yes
No
you cant trust this candidate! from a low-
credibility source Vote for the candidate right
away
you cant trust this candidate! from a
high-credibility source Vote for the candidate
right away
No
Delay of rating
you cant trust this candidate! from a high-
credibility source Vote for the candidate 6
weeks later
you cant trust this candidate! from a
low-credibility source Vote for the candidate 6
weeks later
6 weeks
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Sleeper effect
Discounting cue
No
Yes
Overall mean
No
Delay of rating
6 weeks
Overall mean
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Sleeper effect
Low-credibility
Rating (reject the candidate)
High-credibility
6 weeks
right away
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Example 3 - Bazzini and Shaffers (1999)

• Research Questions
• How individuals respond to attractive alternative
  partners?
• Relationship-maintenance hypothesis Do
  individuals in committed relationships (exclusive
  dater) put down potential dating partners to
  maintain their relationship?
• Relationship-seeking hypothesis Do individuals
  not in committed relationships (nonexclusive
  dater) enhance potential dating partners because
  they are seeking a relationship?

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Bazzini and Shaffers (1999) - Example

• Research Design
• Session 1 college students completed a
  questionnaire about their current dating status
• Session 2
• They were randomly assigned one of the two
  conditions.
• Read a hypothetical scenario describing a
  potential dating partner who was interested in
  the participant (condition 1) or in the
  participants friend (condition 2).
• Rate the attractiveness of the potential dating
  partner on a 15-point scale.

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• Condition 1
• You and your best friend are at Bennigans one
  Friday night. From across the room, you spot an
  extremely attractive guy who has been sitting
  with friends. About 10 minutes ago, his friends
  left, but you notice that he appears to be
  waiting at his table. You get up to use the rest
  room, telling your friend that you will be back
  shortly.
• As you walk back to the table, your waitress
  walks up to you and tells you (in confidence)
  that the person at the other table is her
  brother. She goes on to say that he is very
  interested in meeting you, but doesnt want to
  intrude on you and your friend. When you head
  back to the table, you tell your friend about the
  event. In the meantime, the stranger continues to
  glance over at you, trying to be subtle but
  obviously very interested. Imagine yourself being
  in this situation for a few minutes, reading this
  passage again if necessary.

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• Condition 2
• You and your best friend are at Bennigans one
  Friday night. From across the room, you spot an
  extremely attractive guy who has been sitting
  with friends. About 10minutes ago, his friends
  left, but you notice that he appears to be
  waiting at his table. Your friend gets up to use
  the rest room, and tells you she will be back
  shortly.
• As your friend walks back to the table, your
  waitress walks up to her and tells her something
  (in confidence). When your friend comes back to
  the table, she says that the stranger at the
  other table is the waitress brother. The
  waitress had gone on to say that her brother is
  interested in meeting her but doesnt want to
  intrude on their interaction. In the meantime,
  the stranger continues to glance over at your
  friend, trying to be subtle but obviously very
  interested. Imagine yourself being in this
  situation for a few minutes, reading this passage
  again if necessary.

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Bazzini and Shaffers (1999) - Example

• Independent variables?
• Dating status (in a relationship or not)
• Type of scenario (the stranger is interested in
  you or your friend)
• Dependent variable?
• Perceived attractiveness of the stranger
• Factor vs. Level?
• 2 (exclusive, nonexclusive) x 2 (friend,
  participants)

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Bazzini and Shaffers (1999) - Example

• Mean Table

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Bazzini and Shaffers (1999) - Example
Non exclusive
Mean Rating of attractiveness
Exclusive
Friend Participant
Type of Scenario
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Bazzini and Shaffers (1999) - Example

• ANOVA table

• Source df SS MS F p
• Type of Scenario 1 2.28 2.28 0.74 .300
• Dating Status 1 27.24 27.24 8.78 .001
• Type of Scenario
• X Dating Status 1 16.63 16.63 5.36 .020
• Error 94 291.7 3.10
• Total 97 335.96

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Schedule for Consulting Hours
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Schedule for Research Project

• 4/25 (T) Consulting session for data analysis
• 4/27 (Th) Consulting session for data analysis
• 5/2 (T) demonstration for presentation
• presentation schedule
• workshop for creating a
  PowerPoint file
• 5/4 (Th) Exam 3 Review, Results/Discussion
  draft due
• 5/9 (T) Exam 3
• 5/11 (Th) Class presentation (3 teams)
• 5/16 (T) Class presentation (5 teams)
• 5/18 (Th) Class presentation (5 teams),
  Research paper due

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Results/Discussion (due on 5/4)

• Results
• Descriptive statistics of the major dependent
  variable(s)
• Test your hypothesis present inferential
  statistics (e.g., chi-square, t-test, F-test,
  correlations, regressions)
• Tips follow the examples from the textbook
  (Appendix A) and the sample paper on the web

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Results/Discussion (due on 5/4)

• Discussion
• Brief summary of the purpose of study and the
  main hypotheses
• Interpret the results/findings and discuss their
  implications
• If your hypotheses are not supported, discuss why
• Think about possible factors/explanations
• Significance/Limitations
• Directions for future research
• Tips follow the examples from the textbook
  (Appendix A) and the sample paper on the web