Experimentation Research

Experimentation Research

University of Phoenix

Foundations of Research RES/320

November 30, 2009

Experimentation Research

Introduction

Experiments are defined by Cooper and Schindler (2006) as “studies involving intervention by the researcher beyond that required for measurement” (p. 274). Experimentation research includes both independent and dependent variables. The intervention involves manipulation of an independent variable and observation of how the manipulation affects the subjects participating in the study, the dependent variables. The purpose of this paper is to discuss how experimentation research was used in evaluating mood inductions in persons at high and low risk for alcohol problems. Based on a family history of the presence or absence of alcohol problems, both high and low risk participants were studied to determine reactions to positive and negative mood inductions and a non-alcoholic beer taste test that followed (Randall & Cox, 2001, p. 183-184).

Sampling

An entire population is generally not used when conducting research but rather a sample of the population. A population can be described as a group of individuals with something in common; the common characteristic is known as a parameter. Simply put, a sample is a subset of the population (Webster University, 2009, Populations and Samples section, para 1-2).

Cooper and Schindler (2006, p. 279) state than random sampling procedures in experimental research are very similar to the selection of respondents for a survey. If a sampling frame is free from periodicity that parallels the sampling ratio, systematic sampling may be appropriate. Random assignment is required when making the group assignment in order for the groups to be comparable to the dependent variable. Matching may be used if it is not possible to randomly assign subjects to a group.

In the Randall and Cox experiment (p. 184), the sampling consisted of 80 males, mean age of 22.4...