Methods of Assessment
Psychological testing is a method of assessment that uses standardized tests which measure a sample of behavior (Hogan, 2007). A sample of behavior is a recording of individual performance at specific tasks (Feldman, 2010). Psychological testing is achieved through metrics designed to observe and record specific behaviors or cognitive skills such as academic achievement. An important aspect of psychological testing is creating an objective measuring device such as testing the amount of knowledge in a specific area such as when testing job procedures or skills. For this reason, a psychological test must reflect certain attributes such as credibility and objectivity. There are several categories of psychological testing. These categories cover a number of measures:
Mental Ability Tests
1. Individually Administered
2. Group Administered
3. Other Abilities
2. Single Subject
3. Certification, Licensing
4. Government-sponsored Programs
5. Individual Achievement Tests
1. Objective Tests
2. Projective Techniques
3. Other Approaches
Interests and Attitudes
1. Vocational Interests
2. Attitude Scales Neuropsychological Tests (Hogan, 2007)
One of the most important aspects of psychological testing is the reliability and validity of a test. This aspect of testing is extremely important because it shows whether a particular test is accurate and objective. Poorly made tests can provide inaccurate data and can lead to negative outcomes such as decision making which is based on bad data. This type of issue can be seen in hiring practices of companies which rely on skill tests. If a test of this nature is administered incorrectly or is faulty than a the wrong person can be hired for a particular job. This can waste large amounts of time as well as drive up costs of turnover (Hogan, 2007).
Validity and reliability are statistical concepts which are applied to measuring standards (Feldman, 2010). For example, a statistic is reliable if the results obtained can be duplicated conducting similar research. However, a statistic can be considered invalid (lacking validity) if the research did not measure what it was supposed to measure. Reliability deals with accuracy and precision of the measurement, procedure, and validity is explained using two major forms of validity, which are internal and external. Internal validity is described as the ability of the research instrument to measure what is designed to measure and external validity is he data’s ability to generalized across persons, settings, and times (Feldman, 2010). For example, a measure of learning difficulties may be reliable but invalid if referring to only reading disabilities. This brings into play the idea of relevance. Data can be used to show correlations with disabilities but only if the data is relevant. For example, if the number of reading disabilities are diminishing and learning disabilities are increasing, this does not mean that there is a correlation in the data. This is due to the fact that these disabilities may not be related with one another.
Reliability is a necessary condition for validity, but not the only condition for establishing a test’s validity. For example, a test may provide consistent answers meaning that it is reliable. However, the test would only be valid if the test was actually measuring what it was supposed to be measuring. For instance, a measure of intelligence using the size of brains might provide consistent results but this would not make it valid because brain size does not correlate with intelligence. It is entirely possible for a test to be invalid but produce reliable results when the test is measuring the wrong task or subject (Samaha, 2006).
Due to the importance of psychological testing, it is imperative for researchers to make sure that psychological tests are designed with proper metrics that measure the proper data. This can be a difficult area of testing due to the subjective or lack of understanding in certain areas of knowledge. For instance, intelligence testing is difficult because the nature of intelligence is debatable (Feldman, 2010). For this reason, psychological tests must be designed in a manner which elicits the most objective observations possible.
Feldman, R. S. (2010). Psychology and your life. New York, NY: McGraw Hill.
Hogan, T. P. (2007). Psychological testing: A practical introduction (2 ed.). Hoboken, NJ.
Samaha, J. (2006). Criminal justice. Belmont, CA: Thompson Wadsworth.