Types of Reliability & its Use in Research Methodology with Examples

Introduction of Reliability

Reliability is basically an extent up to which the various techniques that are applied at the time of research produce similar outcomes when number of tests are performed. Some common types of reliability are Parallel form, interrater, test-retest, and internal consistency. It is very crucial to ensure reliability while selecting the design, accumulating and analyzing information. Reliability is all about consistency in the methodology. The two main factors that are kind of investigation that has been performed and the type of research methodology selected helps you in determining the form of reliability to be measured.

For instance:-

While preparing a questionnaire for measuring the IQ level of students. Teacher conduct the two test but at a different time on the same group of students  but there is great variation in the outcome of the test, therefore the test-retest reliability of the Questionnaire designed for judging the IQ level of the student is less reliable

A) Inter-rater reliability: It is also recognized to be as interobserver reliability. It is basically utilized for measuring the extent up to which there is mutual consent between people serving similar things or performing the same activities.

For Example:-

The Research team in a hospital analysis wound healing inpatient.  A rating scale is a tool that is used by the research team for measuring the different phases of the healing wound. In addition to this, the research team has also established a specific standard or criterion for analyzing the different aspects of wounds. After completion of the assessment of the wound by all members of the research team, the comparison between results has been done. The findings of the comparison indicate the correlation among different sets of outcomes which means the test performed has high inter-rater reliability.

B)  A parallel form of reliability: It assists in measuring the correlation between two equal versions of the test. It is mainly utilized when a person has various assessment tools for measuring the same thing.

For instance:-

The Questionnaire has been designed for measuring financial risk faced by the organization, all the questions in the questionnaire are categorized into two segments and participants are also categorized. The teams have been asked to perform tests then the comparison between two different tests performed by both teams A and B  has been done and findings reveal the same results which indicate a high parallel form of reliability.

C)  Internal consistency: It helps in the assessment of the correlation between the numbers of items in a test. There are no requirements for making repetition in a test for measuring the internal consistency. It is always advisable to have a single data set as it will provide you ease in measuring the reliability.

An example of internal consistency:-

Set of statements is designed for analyzing both the pessimistic and optimistic mindset of a group of people. All the participants are asked to rate their agreement about the statement on the rating scale consisting of rating one to five. If in case the test is highly internal consistent then in such case respondents having an optimistic mindset will have high ratings and optimistic would have a low rating.