By:
Yolanda M Harper
Instructor
Marciea McMillian-Robinson
Course
Research Methods
Date
July 30, 2012
Experimental Complex Design
An experiment involving an investigation of the effects of two or more independent variables, simultaneously, is referred to as a Complex Design. Two independent variables (IV), and one dependable variable (DV), constitutes the simplex complex design. The independent variable however, consists of two levels or conditions. The combination of independent variables included in an experiment to explain their effects on the dependent variables is referred to as Factorial Combination (Psychometrics: Complex Designs). The Complex Experimental Designs are of six types (Research Designs, 2012):
• Factorial Design
• Solomon Four Group Design
• Repeated Measures Design
• Counterbalanced Measures Design
• Matched Subjects Design
• Bayesian Probability
Pairing of one independent variable in each level with other independent variable in each level is the base for factorials combining independent variables. A factorial design is known as “2x2 design”, when the four conditions occur in an experiment (Psychometrics: Complex Designs).
Purpose of Experimental Designs
A Factorial Design helps in the examination of the overall effects of one independent variable (say, Type of Writing), together with the overall effects of the other independent variable (say, Type of Instructions), as well as the combined effects of the two independent variables. This overall effect of an independent variable in a complex design is referred to as a main effect, and the overall effect of the independent variables in a complex design is known as interaction effect. It can be also defined as the only effect of the independent variable over the dependent variable, which makes an impression that only that variable was manipulated during the experiment. The interaction effect that occurs while the effects of an independent