PsychologicalTesting And Assessment
PsychologicalTest And Assessment (IntroductionTo Tests And Measurement, Chapter 3-7)
The“PsychologicalTesting and Assessment ”is one of the books that has served students through introductioninto the world of assessment and testing. The book is divided intonumerous chapters (1-17), all of which are logically organized withreadable texts and many examples to aid the user. That book has beeneffective in bringing students into the world of statistics, methodsof measurement and assessments. This paper is a highlight of chapters3-7 from the book “Psychologicaltesting and assessment: an introduction to tests and measurement”
Inorder for a research data collected to of value and of use, then thedata has to be reliable and valid. Reliability can be defined as themeasure of the ‘repeatability’ of findings. This is a measure ofthe possibility of the study producing the same results if it were tobe done for a second time. If the data are repeatable, then it isreliable. On the other hand, validity refers to the credibility ifthe research, as well as, its ‘believability’. It is the extentto which a test is able to measure what it purports to measure. Itcan also be used to mean the extent to which the results that aregained from a test can be used to make accurate predictions (Cohen,Swerdlik & Sturman, 2013).
Oneof the most confusing things in the field of psychology is therelationship between reliability and validity. This is because thereis a probability that measurements made in a test and a research canbe reliable without being valid. Despite this, results cannot bevalid unless they are reliable. This implies that for a test or studyto be valid, and then it must consistently show reliability and mustalso do what it purports to do. For example, for a test score to bejudged as one that is reliable, then it has to produce a consistentscore. For this test score to be considered reliable, then anyreplication of the test should be able to produce similar results.This shows that despite the fact that both reliability and validityare intertwined, reliability can be said to be one of the necessitiesof validity, but is it is not sufficient enough to prove the validity(Cohen,Swerdlik & Sturman, 2013).
Cohen,R., Swerdlik, M. & Sturman, E. (2013). Psychologicaltesting and assessment: an introduction to tests and measurement.New York, NY: McGraw-Hill.