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CAPP Validity

The development of CAPP, while respecting the needs and constraints of industry and the work context, is uncompromisingly based on scientific principles and recent research results in applied psychology. Therefore, the validation of the instruments making up the CAPP system has been performed according to strict psychometric standards. Extensive validation research conducted with a large number of participants over the years has clearly established the quality of the CAPP instruments with respect to:

  • Reliability
  • Face and content validity
  • Construct validity
  • Predictive validity


Many tests in the human resource area are self-evaluation personality scales and questionnaires, consisting of standard items such as simple questions or statements. There are only very few CAPP instruments of this nature. For these, classic item-to-scale reliability has been established. However, most CAPP instruments are measuring performance skills or employ the innovative "fuzzy-set" procedure (see "Tests"). Since these procedures do not depend on items that are combined to scales, the reliability - in the sense of stability of the results - for these instruments has been established via test-retest procedures. Detailed statistical reports of the reliability data are available to professionals for inspection on the net or for downloading (see Info/Contact).

Face and content validity

Face validity is achieved when there is high plausibility that a test actually measures the dimension it claims to measure. Content validity refers to the fact that the test contents needs to adequately reflect the underlying dimension. CAPP instruments either consist of classic published instruments with proven face validity or were developed by SIGMA under the direction of Prof. Scherer based on research results and practical experiences in industry. Thereby, direct correspondence between the tests and the dimensions to be measured was achieved. In addition, a number of psychologists who use the CAPP instruments in their daily human resource work, such as recruitment and development, have helped to establish a high degree of face and content validity of the instruments.

Construct validity

A test is considered to be construct-validated (in terms of content validity) when its scores on certain dimensions correlate significantly with other tests that are supposed to measure similar dimensions. Under the direction of Prof. Scherer, SIGMA has conducted intensive construct validity analyses for each CAPP instrument, studying, separately for each dimension, both the correlations with other CAPP instruments (see the discussion of the "multi-trait, multi-method" approach on the page "Tests") and with tests developed by other researchers. The results have shown a high degree of construct validity in virtually all cases. Detailed statistical reports of the construct validity data are available to professionals for inspection on the net or for downloading (see Info/Contact).


Predictive validity

Predictive validity refers to the correlation of a test result with the concrete behavior or achievement of a candidate and thus the test's capacity to predict future achievements. SIGMA is actively pursuing efforts to collaborate with industry to obtain empirical data on the predictive validity of CAPP dimensions for the future performance of candidates. Research so far has shown high correlations of CAPP dimensions with educational achievement and level of position in a company. It can also be shown that the CAPP profile can predict job satisfaction and general "well-being" or life satisfaction to an important degree. In addition, in a series of research studies in collaboration with industry and international organizations, validity correlations with peer ratings (360 degree) have been obtained. Detailed statistical reports of the data on predictive validity are available to professionals for inspection on the net or for downloading (see Info/Contact).