 Dear students, in last medieval, we talked about reliability and its types. Now we are going to study validity. Validity is the extent to which our scale measures what it claims to measure. In other words, if I say, validity is the measure of checking the truthfulness of our scale which we developed to measure a variable. In other words, to study a variable, the scale that we developed is so truthful that we check its validity to check how well an empirical indicator and the conceptual definition of the construct that the indicator is supposed to measure fit together. The theoretically, the variable that we defined, the measure that we made to assess it fits so much with each other, that is, how much it represents each other. That is, if I talk about the class participation of a variable, then we can check the class participation of the students by checking how much they ask the question to the teacher in the class, what kind of assignments they put in the class, so it can have different items. So, the items that we developed are theoretically representative of the theory, we look at its validity to see this. So, if we look at the reliability and validity as a whole, it can be that you have a reliable scale but it is not valid, that is, there is consistency in it, but the truthfulness does not measure your construct. The second situation can be that the scale you have, its validity is low and its reliability is low. That is, the truthfulness does not measure your concept and the consistency of that measure is not similar. There is dispersion in it. The third thing that can happen is that your scale is reliable and valid. That is, the scale that you developed is the truthfulness of your concept and there is consistency in it. So, we call this scale reliable and a valid scale. When we talk about validity, it also has different types of reliability. The first type that we call face validity, then the second type that we call criterion validity and there are two types ahead of it, concurrent and predictive validity. Then the third type is content validity and the fourth type is construct validity. There are two types ahead of it, convergent and divergent validity. So, in the next module, we will talk about these types of validity in detail, what is face validity, criterion validity, content validity and construct validity. We will discuss them one by one in our upcoming module.