Question

Lesson:

-Factorial designs have more than one independent variable or factors.

-A two way factorial design has two independent variables, a three-way factorial design has three independent variables and so forth.

-A 2x2 design has two factors and two levels of each.

-A 2x3 design also has two factors but one has two levels and one has three.

-A 3x3 design has two factors and each factor has 3 levels.

Each example has 2 independent variables or factors.

Comparison of two training programs

2x2 design

The first independent variable is method of instruction.

Video instruction/instruction manual.

The second independent variable is length of time

Fixed time/Self-regulated time.

The dependent variable = test scores.

I can make this a 2x3 design by adjusting the time to 1 hour/2hour/self-regulated.

Effects:

As you set up the factorial design, the predictions are expressed in the form of expected main effects and interactions.

	Video Instruction	Manual	Overall Means
Timed	22	18	20
Self regulated	18	14	16
Overall Means	20	16

The difference between the two columns means is called the main effect for the mode of presentation. The difference between the means on each row is the main effect for overall timing.

Interactions:

An interaction occurs when two factors acting together produce mean differences that are not explained by the main effects of the two factors.

If we graph our data and the lines that are parallel to each other there is no interaction.

Use statistical analysis to determine if accurate, averages are not 100%

Assignment – EPA - Factorial Designs

Definition- Interactions: An interaction occurs when two factors acting together produce mean differences that are not explained by the main effects of the two factors.

You have duplicated the experiment that we just performed. Your results look like this.

M=20 M=20

M=10 M=10

1. Complete the chart and graph the data.

2. Describe the main effect? Is there an interaction?

Answer 1

Answer to the question)