Psychological tests are the tools that psychologists use to measure the variables they need to be aware of, as well as a balance is used to measure weight, psychology has tools that allow us to know certain parameters about anxiety, emotions and personality, among others However, these tests are only useful if they meet certain quality standards.
Therefore, each measuring instrument is based on the formula X – V E. In this, X represents the measurement given by the test, which is the sum of V (the actual score), plus E (measurement error). shows a way to evaluate the quality of psychological tests, thanks to it we can build instruments where X and V are very similar in all subjects, on the other hand, it is important to mention that the study of how to measure psychological constructs is called psychometry.
- What must we do to build a good instrument?To answer these questions.
- Let’s talk about the aspects to consider when building a good instrument.
- In addition.
- We will also explain the concepts of validity and reliability.
- Which will show us the quality of the test.
- Let’s see this.
Creating a psychological test is a laborious process that requires many hours of work and research. Before you begin the test creation process, you must answer three key questions:
The first question allows us to know the variable studied, it may seem simple to define what you want to measure, but if it is not done correctly can generate a lot of confusion, a historical example of this happened with intelligence: Different instruments began to be used to measure it, but no one defined it. We continue to suffer the consequences, having thousands of different definitions of intelligence building and different tests that measure different things.
A very important aspect when defining a point to measure is what it will be measured with, psychological constructs cannot be observed directly (think, for example, of anxiety), but we can measure them through the behaviors they generate. it is necessary to make very clear the behaviors manifested by the subject’s variables.
The second question serves to adapt the test to the people we want to measure, obviously psychological tests with the same value can not be performed for all ages and conditions, so it is essential to know the state of the target population and adapt the instrument to the needs and qualities of the subjects.
Each test is built with a single goal, and there can be many goals, such as diagnosing a disorder, selecting people, investigating, etc. The third question serves to focus the instrument on its usefulness.
Although two tests aim to measure the same thing, they can be very different if your lens is different. For example, if we’re trying to measure intelligence, we can’t use the same test to detect gifted children or disabilities.
Therefore, the answers to these three questions form the basis of any psychological test. It is essential to have a thorough study of these aspects if we want to build a valid and reliable instrument.
In psychometrics, to measure whether a test performs its function, there are two fundamental indicators, these indicators are validity and reliability. Throughout history many statistical formulas have been created to calculate and check the quality of the tests, but what do these two concepts mean?
When we talk about the validity of a test we mean its ability to measure what they want to measure, that is, if we want to measure a person’s anxiety level, the test will be valid if it measures anxiety and only anxiety. .
It may even seem absurd, to some extent, that a test can measure something we do not want, but when the objective is ill-defined, the creation of the instrument may result in very low validity.
There are several statistical resources to measure the validity of a test, the most common are the correlation of the test to be measured with another, the validity of which has already been tested, the evaluation of the test by several specialists and, ultimately, to observe the extent to which these specialists agree with each other.
Reliability is the scale that indicates the accuracy of a test when measuring its goal, i. e. a test will be reliable when the same person performs the test twice and gets the same result if the result is different each time it is performed, meaning that the measurement error is so high that it distorts the results, it is as if every time we put an object on the scale it has a different weight.
There are also different strategies for measuring reliability, but the best known is to do the same test twice with a group of people and see the correlation between the first and second measurements. A high correlation would show high reliability and indicate that the test is working. his work.
Finally, it is worth mentioning that psychological tests are used in all fields of psychology, most applied to research, so it is essential that their preparation is fully controlled so that the results are valid and reliable.