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Dr. Patrick McCarthy's
Notes on Research Methods
in I/O Psychology


These are some of my notes on research methods in I/O psychology. Actually, the methods and issues described below are relevant to all areas of psychology (not just I/O). You'll find that these notes can supplement your reading and, with any luck, help clarify some key points.


The notes below first outline key steps in the research process, then outline a few of the major types of research methods--and highlights advantages and disadvantages of each. Finally, we'll cover a few key issues in the measurement and statistical analysis of research data.


Steps in the Research Process

1. Determining What Topic to Study

2. Development/Adoption of a Theory

3. Generation of Hypotheses

4. Selection of an Experimental Design

5. Collection of Data

6. Statistical Analysis of Data

7. Interpretation of Results & Drawing Conclusions

8. Further Evaluation & Replication of Findings


Research Methods

Now that we have outlined the basic steps in the research process, below we will delve a bit deeper into one of those important steps. Specifically, the particular method selected for conducting research lays the foundation for how confidently we can claim to better understand the causes of the behavior(s) of interest. It is also fundamental to how likely our conclusions will generalize beyond the particular sample in your study, i.e., how applicable they are to other people or in other places.

The major types of research methods vary in terms of the experimenter's control over relevant variables, and the naturalness of the setting. These differences have a direct bearing on critical issues, such what sorts of conclusions we can make from the findings, and how confident we are of the validity of those conclusions.

You will find the word "experiment" is reserved for specific circumstances. Experimental methods are those in which the experimenter has control over: a) the assignment of subjects to conditions (usually through use of random assignment), and b) the manipulation of the independent variable. If either of these two are not present, then we call it a research study.


Laboratory Experiment


Field Experiment


Field Study


Survey Study


Case Study


Measurement & Statistical Analyses of Data


Key Issues in Measurement

Reliability refers to the consistency of scores produced by a measurement device

Inferential Statistical Analyses of Experimental Data


Correlational Method



Copyright 1997 Patrick M. McCarthy



Last updated: 30 August 1998
URL: http://www.mtsu.edu/~pmccarth/io_methd.htm
Send comments to: pmccarth@mtsu.edu