An example that is reliable but not valid is a broken thermometer. having been to all the lessons and having studied enough. It’s reliable because, assuming that there’s no way a student can cheat, the exam results will be similar for those students who are passing it in similar conditions, e.g. It’s valid because it’s testing the knowledge that the student acquired during the school year, and that’s exactly what it’s designed to do. If the results are always different, they can’t be trusted and, therefore, aren’t reliable.Īn experiment that is both valid and reliable is a high school exam. on how similar are the results when you run the same test over and over again. In contrast, reliability has to do with precision, i.e. about whether the results that are produced are expected or not. When it comes to validity, you’re talking about accuracy, i.e.

The reliability of the statistical estimates can be measured.

We had doubts about the validity of their argument.

It’s interesting that if your findings are consistent when the experiment is repeated because you’re constantly making the same error, the experiment will still be thought of as reliable. In order for the experiment to be reliable, it needs to be performed in a stable environment and without random errors. RELIABILITY, on the other hand, is the extent to which the outcomes are consistent when the experiment is repeated more than once. It also means that the experiment is performed with all the variables taken into consideration, that you covered enough of the subject that you’re testing and that your findings agree with the theoretical assumptions. If an experiment is valid, it means that it has no measurement errors. VALIDITY is the extent to which the instruments that are used in the experiment measure exactly what you want them to measure.

Test reliability and validity examples