How can a research project be reliable but not valid?
1. How can a research project be reliable but not valid?
This question can be answered by definition and example. Let's take a closer look.
Reliability: The extent to which a measurement instrument yields consistent, stable, and uniform results over repeated observations or measurements under the same conditions each time. For example, a scale is unreliable if it weighs a child three times in three minutes and gets three different weights. (1)
Validity: is the strength of our conclusions, inferences or propositions. More formally, Cook and Campbell (1979) define it as the "best available approximation to the truth or ...
This solution explains the question: How can a research project be reliable but not valid? For further detail on the relationship between reliability and validity, an article is also provided.