What is Predictive Validity psychology Testing?

Predictive validity in psychology refers to the ability of a test or assessment measures what it is intended to measure. Understanding the predictive validity psychology definition could help a student do well in their classes or a professional to master an essential skill for their job.

What a Predictive Validity Study Entails

 A person who is new to data science or statistics may wonder, “What is predictive validity?” Predictive validation studies may be done as a way to determine the validity of some other test. These validity studies are widely used across many areas of research and expertise.

A predictive validity study entails determining how well a certain measure, metric or statistic can predict future behavior. It is a type of criterion study. This is an examination of how one variable is able to predict an outcome based on the information that is provided by other variables. It is important that all of the information is collected in an objective manner and using the same measurement standards. Biases or differences in measurement tools could affect a predictive validity study.

Purpose of a Predictive Validity Study

What is predictive research?  The purpose of a predictive validity study is to find out if another measurement is any good at predicting an outcome. If that other test or measurement is found to not be useful at predicting an outcome, then an organization, agency or company may want to look for a different metric or statistic that has high predictive validity.

Since researchers have a limited amount of time and other resources, they have to use them wisely. The predictive validity study can give them evidence as to whether or not the time spent measuring certain criteria has been worthwhile.

How a Predictive Validity Study Is Used

Predictive validity studies are used to predict future behavior, explains Statistics How To. They may be applied to real-world or simulated situations. In the best of circumstances, they are done in a prospective manner. This means that they take a long time to complete.

Predictive validity studies also require a large sample size. The large sample size could be difficult to obtain in some cases, which is part of the reason why it can take a long time to complete a predictive validity study.

Examples of Predictive Validity Studies

When a predictive validity study is conducted in the real world, it is done with a goal in mind. One example of predictive validity would be in college admissions offices. The admissions officer would look at a student’s high school grades and grade point average in order to predict the student’s success in college. Upon college graduation, the admissions team could review all of the data and find out if the people with good high school grades graduated from college on time and whether or not they earned high-grade point averages during their college studies. Admissions officers could also do this type of study with tests such as the Scholastic Aptitude Test (SAT).

In this example, the study takes a significant amount of time to complete.  Data needs to be collected from high school students.  Sometime in the future (four or more years), data needs to be collected again regarding college performance. 

An analysis needs to be completed to determine if there is a positive or negative correlation between high school performance including test scores and GPA, and performance in college.  This analysis could be completed using Pearson correlation coefficient.  This statistical formula measures the linear association between two variables.  Thankfully there is software that can compute this formula.  The Pearson correlation coefficient can tell us the type of linear relationship (positive, negative, or no effect) and the strength of that relationship.  

Human resource staff and recruiters also use predictive validation when hiring new employees.  Potential hires may be asked to complete a cognitive test which has shown the ability to predict future job performance in a specific role.  If the correlation between the test score and job performance was statistically significant, the test would have predictive value.

Other Types of Validation Studies

There are seven common types of validity in psychological research.  We’ll briefly highlight the important features of each.

Face Validity

This is the least scientific type of validity in research.  This is a very surface level analysis.  A researcher might ask a group of random people if they feel like the assessment makes sense for what they are trying to measure.  Face validity is a good starting point but should never be used as the only method of validity.

Construct Validity 

Construct validity demonstrates how well a test or experiment successfully measures what it claims to measure.  You might want to determine whether an elementary school art program actually increased the artistic ability of the students.  Artistic ability is a relatively abstract concept.  The researcher would need work to define the construct they are trying to assess and determine if their assessment tool accurately measures artistic ability.  

There are several psychological tests that have high construct validity.  An IQ test is one of the most well-known tests with high construct validity.  

Content Validity

Content validity focuses on whether the assessment or measurement tool covers all of the content in the construct or behavior being measured.  If someone wanted to measure extroversion, they would need to determine what traits cover this construct.  If an assessment is said to have high content validity, that means the test measures all the attributes of extroversion.

Internal Validity

Internal validity refers to the extent you can be sure your independent variable produces the observed effect.  A study would have internal validity if it can show a trustworthy cause and effect relationship.  A researcher might be interested to see if a motivational app can reduce negative thinking.  If the study showed that negative thinking was reduced after engaging with the motivational app and there were no other variables involved, there would be good internal validity.

External Validity

External validity is the ability of a study to have the same results outside of a controlled setting (like a laboratory) in the real world.  

Concurrent Validity

Concurrent validity is used to assess the extent of agreement between two assessments taken at the same time.  If a student achieved a similar test score on both a paper version and electronic version of a test, the test would have strong concurrent validity.  

Criterion Validity

Criterion validity refers to how accurately a test or assessment measures the outcome it was created to measure.  Scores should predict real life outcomes.  Predictive validity is a variant of this paradigm. 

Understanding the predictive validity definition and how it applies to psychology could help a person advance their career. The proper use of one of these studies could also strengthen the results of a research study.  It could also provide evidence-based justification for the use of specific metrics when analyzing applicants or certain tests. Knowing the answer to the question, “What is a predictive validity study?” is an important step for anyone studying statistics or who will use statistics in their work.

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