Objectivity (test theory)
The objectivity of a scientific experiment or test is understood to mean the independence of the test results from the framework conditions (boundary conditions) and falsifying third-party factors. This means that an investigation must be independent of the spatial conditions, various external influences or investigators. In the course of the analysis process, the subjective impression becomes an intersubjectively comprehensible approach.
The objectivity is one of three main quality criteria of tests. The basic rule is: without objectivity there is no reliability , without reliability there is no validity . In this respect, sufficient objectivity is a necessary but not a sufficient condition for the fulfillment of all other criteria. Objectivity can be divided into three areas:
Implementation objectivity means the degree of independence of the test results from the person of the test director and from the spatial conditions. It follows that maximum standardization of the test situation and minimal social interaction between the test director and the test participant should be aimed for.
Evaluation objectivity means the extent to which the same behavior of a test person is always evaluated in the same way. Here is the objectivity of projective tests, e.g. B. the Rorschach test , rather than low, with standardized intelligence tests such as WAIS-IV (Wechsler Adult Intelligence Scale IV), on the other hand, to be regarded as high or sufficient due to the standardized evaluation. Studies suggest that the evaluation of paper-and-pencil tests with the usual templates can be error-prone and is almost a concentration test in itself. The less freedom the evaluator has in counting the test results, the higher the objectivity of the evaluation.
Objectivity of interpretation
Interpretive objectivity means the extent to which the same test values are interpreted in the same way : It presupposes clear rules according to which a specific diagnostic decision can be derived from a test result. The less defined the conclusions from the result, the more “heuristic” and “more intuitive” the conclusions are drawn from the result, the more the interpretation depends on the subjective skills and experience of the specialist. Objectivity of interpretation is about the question of whether a test is standardized or not. If different standards are used, different interpretations arise. Tables of norms for different populations (e.g. student norms, student norms, etc.) increase the objectivity of interpretation. In DIN 33430 for aptitude diagnostics, clear and scientifically verified rules for interpretation are required, and training and further education standards are also defined for professionals.
As an example, the school grade 1 should indicate a very good performance in all federal states and the grade 5 should be regarded as poor and not sufficient for passing. Interpretation objectivity says nothing about the quality of the content. If the implementation or evaluation objectivity is violated, this also falsifies the statement of the interpretation. It is therefore said that whoever has a 2 in Bavaria may have a 1 in NRW (problem of the lack of standardization in terms of implementation objectivity; everyone makes their own test). The objectivity of interpretation is ensured by standardizing the respective test procedure. It is therefore always given when standard scales are available, since a standard deviation of "+/- 1" always comprises 68.3% of the test values.
- Manfred Amelang, Werner Zielinski: Psychological diagnostics and intervention . 3rd corrected, updated and revised edition. Springer, Berlin et al. 2002, ISBN 3-540-42840-2 , ( Springer textbook ).