The connection and difference between reliability and validity lies in the difference between stability and efficiency, because reliability can be understood as reliability, consistency, stability and validity analysis. In short, it is the validity and accuracy of the questionnaire design. When we design a questionnaire for the research topic, we all hope that the actual measurement of the problem is what we want to measure. The relationship between them is that the reliability is low, the validity cannot be high, the reliability is high, and the validity is not necessarily high, but on the contrary, the reliability is low, the reliability is likely to be high, the validity is high, and the reliability is bound to be high.

The difference between them lies in different estimation objects, different analysis methods and different preconditions. For example, validity can only be based on reliability. If there is no validity, the result with higher reliability is meaningless. This is the relationship between the two.

Its reliability means that the same person takes the same test paper many times, assuming that this person's score has not changed, there will not be much difference, while validity means to what extent this test paper can measure your intelligence level.

Reliability refers to its credibility, that is, to what extent it is correct, and effectiveness refers to how effectively it can express what it needs to express. Take a standardized test paper for measuring intelligence and memory as an example.