87 Role of semantics in a phonics through spelling intervention 4 and orthographic errors was calculated by adding the types of errors as these have been classified in Appendix A. Finally, the percentage of errors for each classification was calculated based on the total number of possible errors for each category per version. Phonics through spelling intervention A phonics through spelling intervention aimed to reach a functional level of technical reading and spelling by means of combining reading and writing in one intervention followingtheprotocolbyBlomert (2006).Uniquetoaphonics throughspellingintervention is that during the intervention, both reading and spelling instruction and exercises were equally balanced in terms of time spent on each topic (50–50). This is rather unique as most studies include less or even no spelling instruction or exercises. Children had a weekly 45-min session with a clinician. The mean length of the intervention was 27.04 weeks (SD = 4.93). Variation in the length of the intervention occurred due to variation in the post-intervention assessment schedule (for instance due to holidays or personal circumstances). Furthermore, variation in the length of the intervention occurred due to variation in time needed to acquire 80%-accuracy levels and improved fluency levels as described below. During the sessions, the clinician tailored the intervention as much as possible to each child’s needs. Explicit direct instruction, guided exercises, and feedback were given according to each child’s needs. Approximately half of the time was spent on reading activities and the other half of the time was spent on spelling activities. The continuity of quality during assessment and intervention was guaranteed by supervision of certified clinical health psychologists. The intervention included two stages: 1. Phonological spelling The intervention started with practice of the phonological base of reading and spelling due to learning the grapheme-phoneme correspondences (GPCs). After learning the GPCs, children learned to use this letter knowledge in reading and writing words and sentences/texts by using an explicit strategy. When children mastered the basic levels, children learned to read and write words based on syllables as well. Accuracy was trained first, followed by efficiency and words and sentences/texts increased in difficulty. Feedback was given on accuracy and later also on efficiency. 2. Orthographic spelling Dutch is a rather transparent language, but still morphological rules and orthographic patterns need to be learned to write and read words (mostly polysyllabic words) correctly. The morphological rules and orthographic patterns can be found in Appendix A and were taught according to each child’s needs.