Research Methods: Reliability
- Refers to consistency of a particular measurement.
- Researchers should be able to measure/test something time after time and get similar results.
- Reliability linked to replicability - ability to repeat a study, which is one of the major features of science.
Types of Reliability
A) External Reliability - ability to produce the same results every time. E.g if same person takes a questionnaire/test at two different times and produces same results, the quesitonnaire/test is reliable.
- Assessing external reliability - external reliability can be checked using the test-retest method. This is where the test/questionnaire is used twice on same ppts. To get a measure of reliability correlate the two scores, the higher the correlation, the more reliable the test/questionnaire.
B) Inter-rater/inter-observer reliability (form of external validity) - concerns whether two interviewers/observers can produce the same outcome and are consistent. The extent to which observers/interviewers agree is known as inter-rater or inter observer reliability.
- Assessing inter-rater reliability - inter-rater reliability can be assessed by correlating the scores of the two observers/interviewers/markers scores to give an indication of reliability. The higher the correlation, the more reliable the observations.
C) Internal reliability - concerned with the…