Validity and Reliability - Essay Example

Validity indicates the level by which a test measures a particular data it is supposed to measure. Validity and Reliability Validity and reliability are two important concepts that measures the quality of the results and data gathered in the process of research (Kimberlin & Winterstein, 2008, p.2276). In psychological research, acceptable data are both reliable and valid for clinical application and reference for future studies. Reliability defines the high level of trust that the recorded data is ‘close to the true value or measure.

’ Thus, repeatability of the results gathered can be considered as a method to test reliability. Validity, on the other hand, indicates the level by which a test measures a particular data it is supposed to measure. Validity encompasses the different parts and phases of a scientific research. Measures can be reliable but not valid but valid measures have to be reliable (Goodwin, 2009, p.134; Huck, 2008, p.88). The paper is aimed to discuss and define the concepts of reliability and validity which includes types of reliability and types of validity are included in the study.

Types of Reliability Reliability evaluates the stability of measures and the equivalence of items from the same test or from the same instrument of research (Kimberlin & Winterstein, 2008, p.2277). There are four types of reliability namely inter-rater, test-retest, parallel-forms and internal consistency. Inter-rater reliability means different people take the same test which improves the reliability by calibrating the method through different types and groups of people. Its main application is for research wherein observations are the main bases of data gathering, with the assumption that there are more than one person gathering data.

Examples of the said type of reliability are the test for similarity in people’s manner of categorizing items and the manner by which people can score items. It is also referred to as inter-observer reliability or inter-coder reliability (Changing Minds, 2011). The test-retest reliability determines the reliability through time because it is undertaken by testing same people during different times. The main assumption is that the test should have the same results regardless of the time it was taken.

This can be attributed to the effects of different factors such as mood, interruptions, time of the day, etc. A measure with high reliability should have little variation regardless of the time the test was taken. It is commonly composed of pre-test and post-test (Franzen, 2000, p.122; Changing Minds, 2011). Parallel-forms reliability is composed of different people at the same time but with different test. It can be undertaken with other methods, such as split-half wherein the test is divided into 2 sections and applied to the same group of people such as national tests (Changing Minds, 2011).

The internal consistency reliability is the last type which is composed of different questions with the same construct with the purpose of determining the response on a given construct or idea. The consistency of the results is based on the different approach that each question offers, thus, the test evaluates each question in terms of the ability to achieve consistent results (Changing Minds, 2011). Types of Validity Validity is important in gauging the data that can be applied and accepted in the professional field.

The different types of validity include construct validity, content validity and criterion-related validity. Construct validity is related to the evidence that can be observed from different studies. An important element in the said type of validity is