The 10 fundamental types of validity in science
We can weigh ourselves on a scale, or measure our height by meter, or assess body temperature with a thermometer. The data we obtain in principle should be objective and reliable, in addition to referring specifically to what we wanted to measure (weight, height or temperature). But what if, in addition to that, they also reflect other things such as volume or color or are influenced by atmospheric pressure or humidity? Our results would not be totally valid, since we would not be looking only at the characteristics that we wanted to value.
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 considered in order to guarantee that we are evaluating what we should evaluate. It is essential, for example, to assess the mental state of a subject or 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 . In this article we are going to review what they are.
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What is validity?
Before looking at the different types of validity, it is advisable to make a brief review of what this term refers to.
It is understood as validity to the property or capacity of a test or other measuring instrument for measure adequately what the instrument has been generated for , independently of the theory or model of the reality from which it was drawn up. It is linked to what is measured and how it is measured, assessing whether the measurement is carried out correctly. This is: that the data of the measurement correspond to the real data.
The validity can be calculated based on the coefficient of validity, based on the degree of correlation between the measured variable and the studied one.
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The different types of validity
Validity is a fundamental property when making measurements of any kind. As we discussed in the introduction, in sciences such as psychology it is essential to take into account this aspect in order to generate valid measurement instruments to assess the status of the people analyzed. But the validity can be considered from different perspectives, being able to find diverse types of validity centered in different aspects.
1. Construct validity
This type of validity refers to the accuracy with which the measuring instrument measures what it is originally intended to measure. In other words, it assesses to what extent the answers or results of the evaluation method used have a specific meaning, existing relationship between the observed and the construct of interest .
2. Content validity
Is the degree to which a measuring instrument contains representative items of the construct or content that is intended to be evaluated. It is valued that aspects of interest that represent the attribute to be evaluated are included in the elements that are part of the measurement. Within it, two major types of validity can be assessed.
3. Apparent validity
Although it is not truly a type of validity, it refers to the degree to which a test appears to value a certain attribute. In other words, it is the appearance of validity that an instrument can give to anyone who looks at it, without any kind of analysis. It has no real significance.
4. Logical validity
It is the type of validity used to generate an instrument and measurement items, depending on the representativeness of what is analyzed in the valued content .
5. Validity of criteria
It refers to degree to which a test correlates with external variables and scales , being able to relate the results of the measurement with a concrete criterion. It also allows to establish predictions.
6. Predictive validity
Type of criterion validity that allows establish predictions regarding behavior , from the comparison between the values of the instrument and the criterion. Usually there is a time between the moment of measurement and the criterion used.
7. Concurrent validity
Both the measurement and the verification of the criterion are carried out at the same time, allowing to relate both elements and assess the current state of the subject.
8. Retrospective validity
Unusual type of validity in which the item or method of evaluation assesses the existence of a certain value or trait in the past. The criterion is taken before the measurement of the test .
9. Convergent validity
This type of validity refers to the validity obtained from the relationship of two measuring instruments. Convergent validity indicates the existence of a relationship between two tests that evaluate the same , that is, it indicates the existence of an interrelation or correspondence between both instruments of measurement.
10Discriminant or divergent validity
Divergent validity is the other side of the currency 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 elements. That is, it is reflected that two instruments referring to two constructs that should be different they have different results .
- Antequera, J. and Hernángomez, L. (2012). Experimental psychology CEDE Preparation Manual PIR, 09. CEDE: Madrid
- Prieto, G .; Delgado, A.R. (2010). Reliability and validity Psychologist papers, 31 (1): 67-74.