The 10 fundamental types of validity in science

These are different ways of assessing the quality of measuring instruments used in science.

We can weigh ourselves on a scale, or measure our height with a meter, or assess our body temperature with a thermometer. The data we obtain should in principle be objective and reliable, as well as referring specifically to what we wanted to measure (weight, height or temperature). But what if they also reflected other things such as volume or color, or were influenced by atmospheric pressure or humidity? Our results would not be fully valid, since we would not be looking only at the characteristics we wanted to assess.

In psychology, a science whose object of study is not directly observable and in which different constructs are analyzed, validity is something that must be carefully taken into account in order to ensure that we are assessing what we should be assessing. It is essential, for example, to evaluate the mental state of a subject or to assess the effectiveness of a treatment. And we must bear in mind that, depending on what is being analyzed, we can find different types of validity, we can find different types of validity. In this article we will review what they are.

What is validity?

Before looking at the different types of validity, it is advisable to review what this term refers to.

Validity is understood as the property or ability of a test or other measuring instrument to to adequately measure that for which the instrument has been generated, regardless of the theory or model of reality from which it has been developed.regardless of the theory or model of reality on the basis of which it was developed. It is linked to what is measured and how it is measured, assessing whether the measurement is carried out correctly. That is: that the measurement data correspond to the actual data.

Validity can be calculated on the basis of the validity coefficient, based on the degree of correlation between the measured variable and the variable under study.

The different types of validity

Validity is a fundamental property when making measurements of any kind. As we have commented in the introduction, in sciences such as psychology, it is essential to take this aspect into account in order to generate valid in order to generate valid measurement instruments to evaluate the state of the people being analyzed. But validity can be considered from different perspectives, and different types of validity focused on different aspects can be found.

Construct validity

This type of validity refers to the accuracy with which the measuring instrument measures what it is intended to measure. In other words, it assesses the extent to which the responses or results of the evaluation method used have a specific meaning, There is a relationship between what is observed and the construct of interest..

Content validity

It is the degree to which a measurement instrument contains items that are representative of the construct or content to be assessed. or content to be evaluated. It is assessed to ensure that the items included in the measurement include aspects of interest that represent the attribute to be evaluated. Two main types of validity can be assessed.

Apparent validity

Although it is not really a type of validity, it refers to the degree to which a test appears to assess a certain attribute. In other words, it is the appearance of validity that an instrument may give to anyone who looks at it, without any kind of analysis. It has no real significance.

4. Logical validity

This is the type of validity used to generate an instrument and measurement items, based on the representativeness of what is analyzed in the assessed content..

5. Criterion validity

Refers to the degree to which a test correlates with external variables and scalesIt is possible to relate the results of the measurement to a specific criterion. It also allows predictions to be made.

6. Predictive validity

Type of criterion validity that allows to establish predictions with respect to behaviorbased on the comparison between the values of the instrument and the criterion. Generally there is a time lag between the time of measurement and the time of the criterion used.

7. Concurrent validity

Both the measurement and the verification of the criterion are carried out at the same time, making it possible to relate both elements and assess the subject's current state.

8. Retrospective validity

An unusual type of validity in which the item or assessment method assesses the existence of a certain value or trait in the past. The criterion is taken before the test measurement..

9. Convergent validity

This type of validity refers to the validity obtained from the relationship of two measurement instruments. Convergent validity indicates the existence of a relationship between two tests that evaluate the same thing, i.e., it indicates the existence of a relationship between two tests that evaluate the same thing.In other words, it indicates the existence of an interrelationship or correspondence between the two measuring instruments.

10. Discriminant or divergent validity

Divergent validity is the other side of the coin of convergent validity. In this case, we are talking about the degree to which two tests or instruments differ, reflecting that two tests are associated with different constructs or items. In other words, it is reflected that two instruments referring to two constructs that should be different have different results..

Bibliographical references

• Antequera, J. and Hernángomez, L. (2012). Experimental psychology. Manual CEDE de Preparación PIR, 09. CEDE: Madrid.
• Prieto, G.; Delgado, A.R. (2010). Reliability and validity. Papeles del psicólogo, 31 (1): 67-74.