Chapter 8, Problem 2RQE

Summary Introduction

Introduction:

Internal invalidity happens when conclusions drawn from an experiment do not accurately indicate the conditions of the experiment. History can be a factor if an event occurs during the experiment that could bias responses. A subject may become bored during an experiment, influencing responses later in the process, a factor called maturation. Instrumentation refers to changes in the way the dependent variable is measured, which throws off results because the later ones cannot be compared to the previous ones. If the control group begins resent what they view as unequal treatment, they may become demoralized and not respond the same way they otherwise might.