 Here we are talking about what kind of validity issues can be seen in assessment, so first of all talking about the types of validity. Validity is not a single static, it is a body of the research that demonstrates the relationship between the test and its behavior, whatever we are intended to measure. So there are basically three main types of validity, the first one is content validity, then construct validity and then criterion related validity and overall there comes a face validity. So content validity assess whether a test is represented of all aspects of its construct. If we are talking about construct then construct is something which has an additional meaning to the concept. Now concept could be the same, just if the chair concept is the same across the world but construct can see an added meaning like we can say its shape can change, its dimension can change. Similarly if we talk about the justice, the concept of justice is same, the construct of justice could have an additional meaning and in every society or culture, the construct of justice can be different that what kind of justice we are talking about. So to produce the valid results the content of a test, survey or measurement method could cover all part of the subject which it is relevant to measure. So our content if it is claiming that it is going to measure aggression, it should only measure aggression yet not any other content or just its items are measuring the same dimension. Then the construct validity, construct validity as I say that when we talk about construct then it has an additional meaning because it can change from society to society from culture to culture. So basically what we are going to measure is specifically we are measuring it. It is central to establish the overall validity of the method like it is not that we are making a scale of eating disorder and we are also looking at dieting beliefs. It should strictly retain to the DSM criteria which is based on eating disorder items. Criterion related validity is a general term to describe how well scores are being measured either they are predictive or they can be criterion. So the two different types of the criterion validity is predictive validity and concurrent validity. So criterion validity means that there should be a certain criteria and how we will use it by saying that this is predictive validity or that is concurrent validity which I will explain to you. Predictability, when we talk about that there is a certain criterion available and predictive validity what will happen is that when the criterion may be obtained at a time after the test. Like we have a certain criteria and we say that in this test all the students above 100 will cross that students will be intelligent students in our academic program. So this is our criteria or we say that if an individual is scoring above 120 on IQ test it will be a very genius individual. Similarly we can predict different types of predictive validity that these students will pass or fail in the future. This individual will be an intellectually good genius individual and this success will happen in different assignments. So we can determine this with predictive validity. Concurrent validity occurs when criterion may be obtained at the same time at the test score. Like we have a criteria and we say that at a certain level we can say that this is mild depression. When scores go up in that criteria we say that this is moderate depression and then this is high depression. So in this way we can assess different things using criteria on the basis of that criteria and that is called concurrent validity. Now the overall important thing is face validity. Another method which is used although it is used rarely but it is very very important because first of all face validity is very important. It means that if you have developer question it should look like a question. It should not look like MCQs. It should not look like multiple choice items. It should not look like two falls. It should look like a questionnaire as you have developed it. So when we are talking about this component the test of the happiness appears to actually mayors level of happiness. If you are giving a happiness test and you read it then its items are claiming that it is measuring different levels of happiness. So it should measure what it looks like to be measured. This is called the face validity.