How do you know your variables are measuring what you think they are? And how do you know they’re doing it well?
A key part of answering these questions is establishing reliability and validity of the measurements that you use in your research study. But the process of establishing reliability and validity is confusing. There are a dizzying number of choices available to you.
by Audrey Schnell, PhD
Some variables are straightforward to measure without error – blood pressure, number of arrests, whether someone knew a word in a second language.
But many – perhaps most – are not. Whenever a measurement has a potential for error, a key criterion for the soundness of that measurement is reliability.
Think of reliability as consistency or repeatability in measurements. (more…)