More Complex Experiments Flashcards
Designs with two or more independent variables
Factorial Design
Simplest factorial design?
2 x 2 Design
What is a 2 x 2 design?
Two independent variables each with two levels
How many cells in a 2 x 2 design?
Four
What is a participant variable?
A level which is selected (measured) but not manipulated - can be used as an independent variable in a factorial design
What is a Main Effect?
The possible effect of each independent variable (independent of the other variables)
How many Main Effects in a 2 x 2 x 2 design?
Three
How do you determine if there was a main effect for Variable A using a bar graph?
Find average point between lines for level One and Two - draw a line - if line is sloped there IS a main effect, otherwise there is not.
How do you determine if there was a main effect for Variable B using a bar graph?
Find midpoint of each line - if they do NOT touch then there IS a main effect, otherwise there is no main effect
What is an Interaction?
When one things changes because (or due) the another variable - interaction of two variables
If lines are parallel what, does this mean?
There is NO interaction
If lines are NOT parallel, what does this mean?
There is an Interaction
When a study finds an interaction and main effects, which is more important?
Interaction
What type of design:
2 X 2 design = 4 independent groups (tested on 1 level each)
Independent group design
What type of design:
2 x 2 design = 1 group (tested on all levels)
Repeated Measure design
What type of design involves 2 groups (IV one) who are each measured on 2 different levels of an independent variable (IV 2)?
Mixed factorial design
What are two ways to make a factorial design more complex?
Increase number of levels of an independent variable (2 x 3)
Increase number of independent variables (2 x 2 x 2)
How many variables in a 2 x 3 design?
2
How many cells in a 2 x 3 design?
6
How many levels in a 2 x 3 design?
5
How many main effects possible in a 2 x 3 design?
2
How many possible interactions in a 2 x 3 design?
1
How many interactions possible in a 2 x 2 x 2 design?
4
AB, AC, BC, ABC
What design is used when you can’t use random assignment?
Quasi-Experimental
What is a parallel group?
When a group doesn’t receive treatment until later so they can be used as a control group