40 Chapter 2 points were given when less time was needed to make the puzzle with a maximum of ten points. All points were counted afterwards. The reliability differs per age but is at least .40 (Kort et al., 2005a). Procedure The current study was based on existing data collected by a clinic for assessment and intervention of children with learning disorders. Between 2009 and 2013, data were filed at this clinic. The following procedures were followed: Assessment started with parents and teacher filling in questionnaires about current problems and child’s development. Afterwards, parents were invited for an interview at the clinic. Both the questionnaires and the interview were in order to rule out other explanations for reading and spelling problems. Assessment took place at a clinic for assessment and intervention of children with learning disorders. Parents brought their children to the clinic in Nijmegen (the Netherlands), and MSc‐graduated clinicians tested the children individually in quiet rooms. Mostly the assessment took two consecutive mornings from about 9.00 a.m. until 12.00 p.m. including breaks. After assessment, clinical reports were written by the MSc‐graduated clinicians. The continuity of quality was guaranteed by supervision of certified clinical health psychologists. The stored files were used for this study. Results Table 2.1 presents the descriptive statistics of all standardizedmeasures. Both raw scores and age‐related scaled scores are given. Prior to the analyses, all scores (except for age) were standardizedusing z‐scores. Z‐scores were calculated by subtracting the mean raw score from each value and then divided that by the standard deviation. A composite score of these z‐scores was computed for phonological awareness, rapid automatized naming, semantic abilities, and perceptual organization. Rapid automatized naming is the only variable in which a negative score means a better performance because rapid automatized naming is expressed in time needed to finish reading letters and digits. In Table 2.2, Pearson correlations are given. All predictor measures were significantly related to word decoding and pseudoword decoding. Furthermore, semantic abilities was found to be significantly related to phonological awareness and rapid automatized naming. Of the covariates, age, and perceptual organization were significantly related to word decoding and pseudoword decoding.