PSYCHOLOGICAL TESTING

PSYCHOLOGICAL TESTING
The field of psychological testing revolves around one basic principle: the understanding, application and analysis of tests. When a person thinks of tests, the first thing that usually comes to mind is the education-based definition of a test, which is a “tool used to systematically obtain a sample of what a student knows or can do” (Dimitrov, 2010). However, testing covers a wide variety of tools that one can use to discover a plethora of data. Four major types of assessments are used in psychological testing: mental ability, achievement, personality and neuropsychology testing. These are the types of tests that are studied by psychologists interested in how assessments can be used to obtain information.
Mental ability tests are used to gauge cognitive functions, such as memory, spatial visualization, and creative thinking (Hogan, 2002). These tests are usually used to assess levels of intelligence. However, there are non-intelligence-based mental ability tests as well. The three forms of mental ability tests most widely used and administered are the individually administered intelligence tests, the group administered intelligence tests and other ability tests. The Stanford-Binet Intelligence Scale provides a worthy example of an individually administered intelligence test, where a person will sit with a trained psychologist, who administers a test that will help evaluate that person- mental abilities. Group administered intelligence tests like the Otis-Lennon School Ability Test are taken in a group setting. The OLSAT is administered to a group of students and is used to judge a student- abilities in regards to certain subjects that involve mental ability. The Scholastic Assessment Test is one of the most recognized non-intelligence based mental ability tests in America and is used to evaluate a student- ability to succeed in an institute of higher learning.

Basic Assumptions
The use of tests in psychology presupposes several assumptions that are foundational to the advent and implementation of any psychological measure. First, examiners must suppose that individual traits and characteristics are measureable, quantifiable, able to be differentiate between individuals, and that the traits describe potentially important aspects of the individual (Hogan, 2007). Second, it must be presumed that these traits and characteristics are reasonably permanent and consistent, so that fluctuations are kept to a minimal. Last, an examiner must be able to observe traits and characteristics through some type of observable behavior. If not, then it would be impossible to quantify the underlying construct. With these assumptions in mind, there are many ways to define psychological tests. The concise definition has already been covered above. Psychological tests can also be classified and defined by the uses of the tests and the people who use the test. What is more, in the field of psychology there are five general categories by which tests are divided.
Major Categories
The first major category of psychological testing encompasses the quantification of mental abilities—through both individually and group administered tests—that measure intelligence, memory, quantitative reasoning, creative thinking, vocabulary, and spatial ability (Hogan, 2007). On the other hand, achievement tests are specifically design to measure knowledge or skills in one particular area—rather than generally—and are administered through the avenues of certifications, licensing, government-sponsored programs, batteries, single-subject tests, and individual achievement tests. Third, personality tests entail using objective personality tests, projective techniques, and other miscellaneous techniques in order to elucidate human personality. The last two categories explore measures of interest and attitudes, and neuropsychology largely through the use of vocational interest measures and tests of brain functioning, respectively. 
Uses and Users
There is no clear-cut distinction between the test used and the context in which it is utilized; however, each context does predominantly use one or more tests (Hogan, 2007). Psychological tests are primarily used in clinical, educational, personnel, and research contexts. Clinical situations entail the use of psychological testing in order to facilitate counseling, school psychology, clinical psychology, and neuropsychology through the use of intelligence tests, objective personality tests, and projective techniques (Hogan, 2007). In the clinical context professional psychologists are usually the examiner and the examinee is someone who has some type of psychological problem. Alternatively, the educational context is most concerned with the use of ability and achievement tests by teachers and educational facilitators to verify student learning or to calculate academic success. Third, ability and personality tests are used in a personnel framework by businesses and the military to choose among applicants for a specific position or to assign already employed individuals to their optimal positions. Last, the research context pertains to the use of the full spectrum of psychological tests as the dependent variable in experiments, describing samples, or even research on the tests themselves. 
Reliability and Validity
Test reliability and test validity are tools used to measure the sustainability and effectiveness of a test. Reliability specifically refers to the consistency, reliability, and dependability of the psychometric results of a test (Hogan, 2007). To be more precise, reliability does not deal with constant errors—errors that universally affect the score of all individuals on the trait being measure—but only unsystematic errors or fluctuations in scores due to different people conducting the test, different instruments being used in the test, or a variation in measurement conditions (Dimitrov, 2010). Conversely, validity is concerned with the explication of test results to a particular interpretation. The interest here is not in the test itself but for the use or purpose of the test. At a very basic level validity entails the applicability of the scores on a test to the trait or construct that is being measured. In particular, a test should never be used for a different clinical purpose than it was originally intended. If that happens, then the test- reliability and the interpretation- validity will be very low (Friberg, 2010). In sum, reliability is wholly concerned with the consistency, replicability, and dependability of the measure being used in a test, and validity involves the applicability of the measure to the use or purpose of the test. Furthermore, it is important to note that for a test to be valid it must be reliable, but a test can be reliable without being valid. 
Conclusion
In all, psychological tests measure trait and characteristic constructs through the use of ability, achievement, personality, interests and attitudes, and neuropsychological tests, to the end of interpreting the results for some use or purpose—within the confines of the aforementioned assumptions. The measures are used in the full plethora of clinical, educational, personnel (business and military), and research contexts. The reliability of these measures is ascertained by considering the unsystematic errors that might render the results replicable or inconsistent. Moreover, the validity of a test result, as it is applies to a specific use or purpose, is built upon the applicability of a set of test scores to the construct being measured. In conclusion, once a test has been deemed reliable, used in its proper context, and applied specifically to a purpose or use (valid) it has been smelted into the cup.






References
Dimitrov, D.M. (2010). Contemporary treatment of reliability and validity in educational
assessment. Mid-Western Educational Research, 23(1), 23-28.
Friberg, J. C. (2010). Child Language Teaching and Therapy. Retrieved from
             http://clt.sagepub.com/content/26/1/77.short?rss=1&ssource=mfc         
Hogan, T.P. (2007). Psychological testing: A practical introduction (2nd ed.). Hoboken, NJ: 
              Wiley