2+ IVs Factorial (between) Mixed (between & within)
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2+ IVs Factorial (between) Mixed (between & within) Group Differences: 2+ Independent Variables
description
Group Differences: 2+ Independent Variables. 2+ IVs Factorial (between) Mixed (between & within). Main Effects. Imagine a study about eyewitness recall of crime. IV #1 = two levels (violent versus non-violent) An Independent t-test. - PowerPoint PPT Presentation
Transcript of 2+ IVs Factorial (between) Mixed (between & within)
2+ IVs Factorial (between) Mixed (between & within)
Group Differences:2+ Independent Variables
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
http://www.upa.pdx.edu/IOA/newsom/pa551/lectur12.htm
No Violence Violence
memory high low
Main EffectsMain Effects
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
http://www.upa.pdx.edu/IOA/newsom/pa551/lectur12.htm
No Violence Violence
memory high low
Main EffectsMain Effects
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
http://www.upa.pdx.edu/IOA/newsom/pa551/lectur12.htm
No Violence Violence
memory high low
No Training Training
No Violence 4 7
Violence 2 5
Main EffectsMain Effects
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
http://www.upa.pdx.edu/IOA/newsom/pa551/lectur12.htm
No Violence Violence
memory high low
No Training Training
No Violence 4 7 5.5
Violence 2 5 3.5
Main EffectsMain Effects
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
http://www.upa.pdx.edu/IOA/newsom/pa551/lectur12.htm
No Violence Violence
memory high low
No Training Training
No Violence 4 7
Violence 2 5
3 6
Main EffectsMain Effects
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
http://www.upa.pdx.edu/IOA/newsom/pa551/lectur12.htm
No Violence Violence
memory high low
No Training Training
No Violence 4 7 5.5
Violence 2 5 3.5
3 6
Main EffectsMain Effects
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
No Violence Violence
memory high low
No Training Training
No Violence 4 7 5.5
Violence 2 5 3.5
3 6
Main EffectsMain Effects
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
No Violence Violence
memory high low
No Training Training
No Violence 4 7 5.5
Violence 2 5 3.5
3 6
InteractionInteraction
No Training Training
No Violence 4 11 7.5
Violence 2 5 3.5
3 8
• Imagine a study about eyewitness recall of crime.• IV #1 = two levels (violent versus non-violent)
– An Independent t-test.
• IV #2 = two levels (training to remember, no training)
– Another independent t-test.No Training Training
memory low high
No Violence Violence
memory high low
InteractionInteraction
No Training Training
No Violence 4 11 7.5
Violence 2 5 3.5
3 8
• Interactions are when the effect of two or more variables is not simply additive.
InteractionInteraction
• Interactions are when the effect of two or more variables is not simply additive.
• Terminology:– Presence of number refers to variable
• 2 x 2 = 2 IVs. 2 x 3 = 2 IVs. 2 x 2 x 2 = 3 IVs– Content of number refers to levels within variable
• 2 x 3 = 2 levels within IV1, 3 levels within IV2
InteractionInteraction
• Interactions are when the effect of two or more variables is not simply additive.
• Terminology:– Presence of number refers to variable
• 2 x 2 = 2 IVs. 2 x 3 = 2 IVs. 2 x 2 x 2 = 3 IVs– Content of number refers to levels within variable
• 2 x 3 = 2 levels within IV1, 3 levels within IV2
– Interaction (INT) = F-test across IV – Main Effect (ME) = F-test within IV– Simple Effect (SE) = pairwise between any two points
InteractionInteraction
• Can have ME separate from INT
InteractionsInteractions
• There are different levels of Interactions. – A “Two-Way” Interaction can occur between any two variables (A-B)
– A “Three-Way” Interaction can occur between any three variables (A-B-C)
– A “Four-Way” Interaction can occur between any four variables (A-B-C-D)
InteractionsInteractions
• There are different levels of Interactions. – A “Two-Way” Interaction can occur between any two variables (A-B)
– A “Three-Way” Interaction can occur between any three variables (A-B-C)
– A “Four-Way” Interaction can occur between any four variables (A-B-C-D)
• If you have 2 variables, then possibility of: 1 Two-Way (AB)
InteractionsInteractions
• There are different levels of Interactions. – A “Two-Way” Interaction can occur between any two variables (A-B)
– A “Three-Way” Interaction can occur between any three variables (A-B-C)
– A “Four-Way” Interaction can occur between any four variables (A-B-C-D)
• If you have 2 variables, then possibility of: 1 Two-Way (AB)
• If you have 3 variables, then possibility of: 1 Three-Way (ABC)
3 Two-Way (AB, AC, BC)
InteractionsInteractions
• There are different levels of Interactions. – A “Two-Way” Interaction can occur between any two variables (A-B)
– A “Three-Way” Interaction can occur between any three variables (A-B-C)
– A “Four-Way” Interaction can occur between any four variables (A-B-C-D)
• If you have 2 variables, then possibility of: 1 Two-Way (AB)
• If you have 3 variables, then possibility of: 1 Three-Way (ABC)
3 Two-Way (AB, AC, BC)
• If you have 4 variables, then possibility of: 1 Four-Way (ABCD)
4 Three-Way (ABC, ABD, ACD, BCD)
6 Two-Way (AB, AC, AD, BC, BD, CD)
InteractionsInteractions
• IV1 (sex: male, female)• IV2 (victim of crime: yes, no)• DV – errors1a
BetweenBetween
• IV1 (sex: male, female) between• IV2 (pretest, posttest) within• DV – errors1a
MixedMixed
