Considering training effects in performance tests - the case of the D2-attention test

A widely applied test used to measure selective attention and concentration is the d2-attention test. There is however, a training effect when this test is repeatedly carried out. The aim of this paper is to provide a methodological approach to adjust for training effects in studies designed to detect intra-individual differences. In total, the d2-attention test was presented 9 times to a total number of 20 subjects. It was presented 5 times under the same conditions. Taking into account the test results under the same conditions only, a logarithmic training effect function was developed for each subject. The constant varies between 290 and 520, and the factor varies between 50 and 150. Some subjects were already successful from the first application of the d2-test, while others showed a steeper learning curve. Performance test designs should generally consider possible training effects. Individual training effect functions to adjust for training effects are strongly recommended.