Validity and reliability are important concepts in research used to evaluate quality and accuracy of measurement methods and data.
To understand the concept of Validity and reliability, you can apply it to everyday use to get a sense of what it could mean mean (for example, is that writer’s opinion valid; is the courier service reliable). In research, however, their use is more complex.
Suppose a study shows stress levels of workers during an economic downturn, and the study used a questionnaire to ask workers about their mental health over a number of years.
You need to check the strength of this questionnaire and ask questions such as whether it is valid and reliable?
Reliability
Reliability refers to the consistency of a measure; whether the results can be reproduced under the same conditions.
Cronbach’s Alpha is used to assess reliability (internal consistency) in research studies. It is commonly used with questions in a questionnaire that use a Likert scale to determine if the scale is reliable.
Cronbach’s alpha values can range from 0 to 1. A higher number indicates better internal consistency between the items.
Validity
Validity refers to the accuracy of a measure; whether the results really do represent what they are supposed to measure).
There a a wide range of factors which influence validity and reliability such as:
- Number of participants that take part in your research (sample size)
- The groups of people that you choose to take part in your research (sample group)
- How long your research will take (time horizons)
There are more such decisions in your research design which can affect the validity and reliability of your study.
Related:
Also understand the complete Research Process
