Chapter 10 Notes and Homework
- Factorial designs: design in which we study 2 or more independent variables
- Factors= independent variables in factorial designs
- Two factor experiment: simplest, has only 2 factors (IVs)
- 2 kinds of info:
- The effects of each IV in the experiment (main effects) and…
- We can answer this question… “How does the influence of one IV affect the influence of another in the experiment?”
- Main effect: the action of a single IV in an experiment; a change in behavior associated with a change in the value of a single IV within the experiment
- 1 IV=I main effect, etc.
- Interaction: one is present if the effect of one IV changes across the levels of another IV
- Higher-order interactions: an interaction effect involving more than 2 IVs
- Design matrix: makes it easier to understand what you are testing and what kind of design you are using and how many treatment conditions are required
- 2x2 factorial design= shorthand notation
- i.e. 2x2 has 2 factors, 4 conditions (2x2=4)
- i.e. 2x3x2 factorial design has 3 factors; 1st has 2 levels, the 2nd has 3, and the 3rd has 2 and 12 separate conditions
- graphs of data that reflect an interaction always have this pattern: lines are not parallel
- one of the key reasons for doing factorial research is measuring interaction
- main effects and interactions are quantified and evaluated through statistical tests
- only 3 possible effects for a two factor between subjects design: a main effect for each factor and an interaction between the two factors
Homework
- In a multiple groups design there are more than two groups of subjects but there is only one independent variable being tested, so the groups are run through two treatment conditions to see if the independent variable has an effect. A factorial design can have the different groups of subjects, but it also manipulates more than one independent variable.
- A main effect is the action or effect that each independent variable has in the experiment. An interaction is the effect of one independent variable changing across the levels of another IV.
- Factorial designs have the advantage of testing more than one factor at a time, which saves time, money, and is more efficient. It also allows for us to measure main effects of each variable and interactions of one IV changing across another.
- A two-factor between subjects design
5.
Step 1: Factor 1 (Gender), Factor 2 (Type of toy), | Step 2: Factor 1 (Gender) Boy Girl Factor 2 (Type of Toy) |
Step 3: Factor 1 (Gender) Boy Girl Factor 2 (Type of toy) Building Not building | Step 4: see table below |
Factor 1: (Gender)____ Boy AND Factor 2: (Type of Toy) Building | Factor 1: (Gender)____ Girl AND Factor 2: (Type of Toy) Building |
Factor 1: (Gender) Boy AND Factor 2: (Type of Toy) Not building | Factor 1: (Gender) Girl AND Factor 2: (Type of Toy) Not building |
6. Labeling Method 1: 2x2 (Gender x Type of toy) between-subjects factorial design
Labeling Method 2: 2(Gender) x 2(Type of toy) between-subjects factorial design
Labeling Method 3: 2x2 (Gender: boy, girl x Type of toy: building, not building)
between-subjects factorial design
Labeling Method 4: 2(boy or girl) x 2(Building or not building) between-subjects
factorial design
Factor 1: (Music) Radio On AND Factor 2: (List Length) Long | Factor 1: (Music) Radio Off AND Factor 2: (List Length) Long |
Factor 1: (Music) Radio On AND Factor 2: (List Length) Short | Factor 1: (Music) Radio Off AND Factor 2: (List Length) Short |
7. a. 2x2 factorial design, b.
c. one extraneous variable could be the volume at which the radio is played, another could be the difficulty of the list to be learned, and another could be the subject’s gpa or tolerance level of noise because some individuals are able to concentrate better at higher noise levels than others
8. The features of an experimental hypothesis that are
important in selecting a design are the number of independent variables to be in the study, if there will be more than two levels of an independent variable and if one of them is the control condition, if the variable is measurable, etc.
9. a. the design of this experiment is a two factor experiment, the shorthand is 2x2 factorial design, and the diagram…
Factor 2: (Primed Condition) Independence AND Factor 3: (Gender) Male | Factor 2: (Primed Condition) Interdependence AND Factor 3: (Gender) Male |
Factor 2: (Primed Condition) Independence AND Factor 3: (Gender) Female | Factor 2: (Primed Condition) Interdependence AND Factor 3: (Gender) Female |
b. Two main effects were reported:
the subjects in the independent condition seated themselves farther away from the chair that appeared occupied than subjects in the interdependent condition and also, men tended to sit further away from the jacket than women did.
c. Refer to below image and also see attached document titled 'graph 9c':
10. Refer to image below and see also attached document titled 'line graph 10':