Experimental Design II: Factorial Designs Flashcards
Factorial designs involve any study with…
more than one independent variable (or factor)
A factorial design is described with a numbering system. Each digit in the system represents…
an independent variable
A factorial design is described with a numbering system. The numerical value of each digit indicates…
the number of levels of each independent variable
Interpret a 2 x 3 factorial design using the numbering system.
Two independent variables. The first has two levels and the second has three levels
The total number of conditions to be tested in a factorial study can be identified by looking at all possible combinations of the levels of each independent variable. This produces a display called…
a factorial matrix
The number of conditions in any factorial design can be determined by…
multiplying the numbers
How many conditions does a 2 x 5 factorial design have?
ten
In factorial studies, two kinds of results occur:
- Main effects
2. Interactions
Main effects
The difference between the means of the levels of any one independent variable
Ex; in a study with two independent variables, such as a 2 x 2 factorial, there can be at most, two significant main effects
When all of the row and column means are the same, there are no main effects
Interactions
Occurs when the effect of one independent variable depends on the level of another independent variable
If lines on the graph are parallel, then no interaction is present
Error bars
Tell you the amount of variability in a set of scores
P x E factorial design
A factorial design with at least one subject factor (P=person variable) and one manipulated factor (E = environmental variable)
Mixed P x E factorial design
A mixed design with at least one subject factor and one manipulated factor
In a P x E design, causal conclusions can be drawn if a significant main effect occurs for the __________ factor.
environmental
In a P x E design, causal conclusions cannot be drawn if a(n) ___________ occurs
interaction
