The reliability and validity of the test is what?

* Reliability and validity of the test are the characteristics of the compliance of the study with formal criteria that determine the quality and suitability for application in practice.

What is Reliability

In the course of testing the reliability of the test, the consistency of the results obtained is assessed when the test is repeated. Data discrepancies should be absent or insignificant. Otherwise, it is impossible to relate to the results of the test with confidence.

The reliability of the test is a criterion that indicates the accuracy of the measurements. The following test properties are considered essential:

• Reproducibility of the results obtained from the study;
• The degree of accuracy of the measurement procedure or the corresponding instruments;
• Stability of the results over a period of time.

In the interpretation of reliability, the following main components can be distinguished:

• Reliability of the measuring instrument (namely literacy and objectivity of the test task), which can be estimated by calculating the corresponding coefficient;
• The stability of the feature under study over a long period of time, as well as the predictability and smoothness of its fluctuations;
• Objectivity of the result (that is, its independence from the personal preferences of the researcher).

Reliability factors

The degree of reliability can be affected by a number of negative factors, the most significant of which are the following:

• Imperfection of the methodology (incorrect or inaccurate instructions, fuzzy statement of tasks);
• Temporary instability or constant fluctuations in the values of the indicator that is being investigated;
• Inconsistency of the situation in which the initial and repeated studies are carried out;
• The changing behavior of the researcher, as well as the instability of the subject's condition;
• Subjective approach in evaluating test results.

Methods for assessing the reliability of a test

In determining the reliability of the test, the following techniques can be used.

The method of re-testing is one of the most common. It allows you to establish the degree of correlation between the results of the research, as well as the time at which they were conducted. This method is simple and efficient. Nevertheless, in subjects, as a rule, repeated studies cause irritation and negative reactions.

The method for checking internal consistency does not take into account the consistency of the results obtained in the re-examination of the results. He establishes the relationship between the answers that were given in one experiment. The test questions are divided into two lists (according to a certain principle), after which the correlation coefficient between the results is calculated.

The method of equivalent forms consists in using two or more tests with different statements of tasks, but with the same essence, form and degree of complexity of implementation. The reliability of the test is indicated by the same or approximate results, which were obtained using the same measuring instrument or computational formula. If the results are highly divergent, then most likely they have been distorted intentionally or the subject has not very responsibly approached the survey process.

What is validity?

The validity of the test is a criterion that determines the reliability of the measurement. We can say that this is the suitability of one or another toolkit to evaluate a particular psychological characteristic. It should be noted that the validity, reliability of the test are mutually complementary criteria, individually they are insignificant.

Validity can be viewed from the point of view of a theoretical and pragmatic aspect. In the first case, it is a method of evaluation or a measuring instrument. As for the second understanding of validity, it concerns the purpose of conducting research activities. It should be noted that this criterion can differ significantly for the same test, depending on the range of subjects. The highest estimate can fluctuate around 80%.

The validity of a psychological test can be assessed in accordance with quantitative or qualitative indicators. In the first case we are talking about carrying out mathematical calculations. A qualitative assessment is made descriptively, based on logical conclusions.

Types of validity of the test

There are the following main varieties of test validity:

• The constructive validity of the test is a criterion used in the evaluation of a test having a hierarchical structure (used in the process of studying complex psychological phenomena);
• Validity by criterion implies a comparison of the results of testing with the level of development in the subject of one or another psychological characteristic;
• Validity in content determines the conformity of the methodology to the phenomenon under study, as well as the range of parameters that it covers;
• Prognostic validity is a qualitative indicator that allows to evaluate the perspective development of a parameter.

Types of validity criteria

The validity of the test is one of the indicators that makes it possible to assess the adequacy and suitability of the methodology for studying a particular phenomenon. There are four main criteria that can affect it:

• The criterion of the performer (this refers to the qualifications and experience of the researcher);
• Subjective criteria (the ratio of the subject to a particular phenomenon, which affects the final result of the test);
• Physiological criteria (state of health, fatigue and other characteristics that may have a significant impact on the final result of testing);
• The randomness criterion (takes place in determining the probability of occurrence of an event).

The validity criterion is an independent source of data about a particular phenomenon (psychological property), the study of which is conducted through testing. Until the results are checked for compliance with the criterion, it is impossible to judge the validity.

Basic requirements to the criteria

External criteria that affect the validity of the test must meet the following basic requirements:

• Correspondence to the sphere in which research, relevance, and also the semantic connection with the diagnostic model are carried out;
• Absence of any interference or sharp discontinuities in the sample (the point is that all participants in the experiment must comply with pre-established parameters and be in similar conditions);
• The investigated parameter should be reliable, constant and not subject to sharp changes.

Ways to establish validity

Checking the validity of tests can be done in several ways.

Evaluation of apparent validity implies testing the conformity of the test to its intended use.

Evaluation of the content validity is a verification of the methodology for the presence in it of all the components necessary for a comprehensive study of a particular phenomenon or factor.

An estimation of constructive validity is carried out when a number of experiments are carried out to study a certain complex indicator. It includes:

• Convergent validation - verification of the relationship between estimates obtained using various complex techniques;
• Divergent validation, which consists in the fact that the methodology does not imply the evaluation of extraneous indicators that do not concern the main study.

Estimation of predictive validity implies the establishment of the possibility of predicting the future fluctuation of the indicator under study.

conclusions

Validity and reliability of tests are complementary indicators that give the most complete assessment of the validity and significance of research results. Often they are determined simultaneously.

Reliability shows how much the test results can be trusted. It means their constancy at each repeated carrying out of the similar test with the same participants. A low degree of reliability can indicate intentional distortion or an irresponsible approach.

The concept of test validity is related to the qualitative side of the experiment. It is about whether the chosen tool is relevant to the evaluation of a particular psychological phenomenon. Here both qualitative indicators (theoretical estimation) and quantitative (calculation of the corresponding coefficients) can be applied.