1, definition of measurement validity:
The ratio of the variation related to the measurement purpose (that is, the effective variation) to the variation of the measured value. The validity of the test is affected by random error and systematic error. A credible test, that is, a test with high reliability, is not necessarily effective and highly effective. An effective test must be credible. Reliability is a necessary condition for validity. The relationship between reliability and validity is that high reliability only provides the possibility for high efficiency, which is a necessary condition for high efficiency, but not a sufficient condition. Validity index is the most important attribute necessary for a good test.
2. Characteristics of test effectiveness:
Accuracy: A highly effective test can accurately measure the attributes or characteristics to be measured.
Pertinence: Effectiveness is a relative concept. Different tests have different validity standards for different purposes and objects.
Stability: A highly effective test can stably measure the properties or characteristics to be tested at different times, places and conditions.
Interpretability: The results of highly effective tests should be able to clearly explain and explain the attributes or characteristics to be measured.
Independence: A highly effective test should be as independent as possible from other factors, such as the subjective bias of testers and the test environment.
The role of test validity:
1, evaluating the quality of measuring tools:
Validity is one of the important indexes to evaluate the quality of measuring tools. A highly effective test can accurately measure the properties or characteristics to be tested, thus providing reliable data support for research or practice.
2, to guide the writing and revision of test questions:
Validity analysis can provide guidance for the compilation and revision of the test. By analyzing the validity of the test, we can find the problems and shortcomings in the test, so as to make targeted modifications and improvements.
3. Improve the accuracy and reliability of the research;
Efficient testing can improve the accuracy and reliability of research. In the research, if the validity of the test used is not high, the data obtained may be biased or inaccurate, thus affecting the credibility and accuracy of the research results.
4, the effect of promoting practical application:
The test has high validity and can provide effective support and guidance for practical application. For example, in the field of education, an efficient test can accurately evaluate students' learning level and ability, thus providing targeted guidance and suggestions for teaching.