Effect of Stroke-level Intra-writer Normalization on Computerized Assessment of Developmental Dysgraphia

Developmental dysgraphia (DD) can negatively influence writing speed, legibility of written product, and even planning and content generation. This could have a detrimental impact on self-expression, and communication in childhood. The goal of this study is to investigate new intra-writer and self-esteem normalization methods (IWN) in direction of improving computerized DD assessment based on the quantitative analysis of online handwriting. For this purpose we enrolled 97 children who wrote a paragraph using a digitizing tablet. Their handwriting proficiency was rated by the Handwriting Proficiency Screening Questionnaire (HPSQ). The handwriting was parametrized using a conventional set of features that were consequently normalized by four newly designed IWN. Based on the results we observed that a stroke-level ℓ₂ norm normalization decreased the computerized DD assessment error from 23 % to 18 %. This study proves that the stroke-level IWN has the significant potential in the field of computerized DD diagnosis and assessment.