In this publication we present the investigation of the spelling progress of children working with Dybuster. We analyze the spelling behavior by means of learning curves based on the collected log file data of the two user studies. First, we compare the learning progress from the first and the second study. This allows for an evaluation of the phoneme-based enhancements, consisting of a new phonological code and an adaptive word selection controller, implemented in the learning software. We expect the dyslexic children who work with the enhanced software version to improve their spelling behavior significantly faster than dyslexic individuals who work with the original version. Second, based on data collected in our second study, we investigate the influence of different cognitive factors on the learning progress. These factors include: the indication of dyslexia, attention functions, and memory performances. Comparing children with and without dyslexia allows us to explore whether both groups benefit to the same extent from the training or if children with dyslexia, irrespective of the method used, generally experience more problems acquiring spelling knowledge. We decided to evaluate attention and memory functions because, on the one hand, it has been suggested that reading problems are associated with impaired memory functions, which in turn cause reduced phonological representations. On the other hand, attention functions build the general basis for learning, since attention processes control all functions of our cognitive system, provided that tasks are not over-learned and automated. Attention helps people focus on the relevant information. Therefore, we aim to examine the influence of memory and attention functions on the spelling progress acquired in a structured environment.
Our results demonstrate that the phoneme-based enhancements implemented in the Dybuster spelling software positively influence the spelling performance of dyslexic children. The participants working with the studentadaptive software version show a significantly increased learning progress. Additionally, there is evidence that both children with and without dyslexia profit from the computer-based training in a similar way. Both groups were able to use the visual and auditory coding system implemented in the learning software to acquire spelling skills and facilitate the memorization of phonological information. Children with low (vs. high) attentional performances could benefit equally from the structured computer-based learning software. This finding implicates that children with low attention resources need clear guidance and may benefit from a structured methodological approach. Moreover, we were able to show that memory functions correlate positively with learning progress irrespective of dyslexia. This indicates that memory functions are important cognitive sources for acquiring spelling skills.