Summary Experimental design: factorial designs

PSYC 301
EXPERIMENTAL
RESEARCH
DESIGN
LECTURE 5

, RECAP
• In Ch 7, 8 and 9 we discussed experimental research which
typically focuses on one IV (expected to influence behaviour
and one DV (measure of the behaviour).
• Then in Ch10 we looked at the non-experimental and quasi-
experimental designs that similarly measure the relationship
between two variables.
• However as discussed previously, in real life variables rarely
exist in isolation.
• Behaviour is usually influenced by a variety of different
variables acting and interacting simultaneously.

,• To examine these more complex real life situations, researc
often design research studies that include more than one IV
quasi-independent variable).
• In experiments where there is more than one IV, the IVs are
commonly called factors.
• Thus, research involving two or more factors is called a
factorial design.

, FACTORIAL DESIGNS
• Factorial designs are often referred to by the number of the
factors. Such as a two-factor design or three factor design.
• A research study with only one factor is often called a singl
factor design.
• Generically each factor is denoted by a letter (A, B, C, etc.)
• Factorial designs use a notation system that identifies bo
the number of factors and number of values (or levels)
that exist for each factor.