LIBRENG SIT IN PSYCHOMETRICS EP. 12: VALIDITY OF PSYCHOLOGICAL TESTS (PT. 2)

Summary

This script delves into the concept of validity in psychological testing, emphasizing its importance in predicting future behaviors and thoughts. It distinguishes between concurrent and predictive validity, explaining how tests like the High Risk of Suicide Test (HRST) can forecast outcomes with high scorers. The speaker outlines steps for establishing validity, using criteria such as GPA or supervisor ratings, and highlights the benefits of predictive validity in hiring and preventive actions, ultimately advocating for its establishment in test development for better decision-making.

Takeaways

• 🔍 Validity in psychological testing refers to the ability of a test to measure what it claims to measure and to predict future thinking and behavior.
• 📊 There are two main types of validity discussed: concurrent validity and predictive validity. Concurrent validity assesses if a test can predict an already existing criterion, while predictive validity checks if it can predict a future criterion.
• 📚 The script explains that a criterion is a numerical expression or observable indicator of a test construct, such as GPA for intelligence or supervisor ratings for job efficiency.
• 📝 The importance of establishing validity is emphasized, as it helps in minimizing errors in hiring and making informed decisions, such as awarding scholarships or identifying students at risk of depression.
• 🔑 The concept of 'construct' is distinguished from 'criterion', with the former being an abstract concept measured by psychological tests and the latter being its concrete or numerical expression.
• 📉 The process of establishing validity involves administering a test, selecting an appropriate criterion, and then correlating the test scores with the criterion to determine the strength of the relationship.
• 📈 A high correlation coefficient, such as 0.93, indicates a strong relationship between test scores and the criterion, suggesting good predictive or concurrent validity.
• 📊 The difference between concurrent and predictive validity is highlighted, with predictive validity requiring a wait for the criterion to manifest, making concurrent validity potentially more time-efficient.
• 🛠️ The script provides a hypothetical example of a suicide risk test (HRST) to illustrate how predictive validity can be assessed and its importance in identifying individuals at risk.
• 🏫 An example scenario involving a school's chief psychometrician is used to explain the steps to determine if a test can predict students' future college grades, emphasizing the role of GPA as a criterion.
• 🏢 Another example involving a job efficiency test is given to demonstrate how a test's scores can be correlated with supervisors' ratings to establish concurrent validity in a workplace setting.

Q & A

What is the primary purpose of validity in psychological testing?

The primary purpose of validity in psychological testing is to ensure that the test measures what it claims to measure and can predict future thinking and behavior.

What are the two types of validity discussed in the script?

The two types of validity discussed are concurrent validity and predictive validity.

How does predictive validity differ from concurrent validity?

Predictive validity involves predicting future outcomes based on test scores, while concurrent validity involves correlating test scores with existing criteria.

What is a criterion in the context of psychological testing?

A criterion is a numerical expression or observable indicator of a test construct, such as school GPA for intelligence or supervisors' ratings for job efficiency.

Why is it important to establish the validity of a psychological test?

Establishing the validity of a psychological test is important to ensure it can accurately predict future thinking and behavior, which aids in decision-making processes such as hiring or scholarship allocation.

What is the significance of a high correlation coefficient in establishing validity?

A high correlation coefficient indicates a strong relationship between test scores and the criterion, suggesting that the test has good predictive or concurrent validity.

How can predictive validity be used in a corporate setting?

Predictive validity can minimize errors in hiring by identifying high and low performers based on test scores, leading to more informed hiring decisions.

What is the hypothetical test mentioned in the script for the purpose of explanation?

The hypothetical test mentioned is a 'High Risk of Suicide Test' (HRST), used to illustrate the concept of predictive validity.

What steps are involved in establishing concurrent validity for a test measuring intelligence in a school setting?

The steps include administering the test to incoming first-year students, waiting until their fourth year, and then correlating their test scores with their GPA to establish concurrent validity.

How does the case of the job efficiency test illustrate the concept of concurrent validity?

The job efficiency test is administered to existing employees, and their test scores are correlated with their supervisors' ratings from the previous month, demonstrating the test's ability to predict an existing criterion.

Why might a test developer prefer to establish predictive validity over concurrent validity?

A test developer might prefer predictive validity because it can predict future outcomes, which is more useful for long-term decision-making and planning compared to concurrent validity.