Background There is a need for instruments with acceptable psychometric properties for measuring time management/time processing ability. KaTid-Child (Swedish: Kit for assessing Time processing ability) was developed for children aged 5–10 years. To meet needs of assessing older children, KaTid-Youth was created. The aim of this study was to investigate the validity of KaTid-Youth.
Methods This study investigates the validity of KaTid-Youth using Rasch models: partial credit and common item equating.
Results Results indicate that KaTid-Youth has acceptable psychometric properties and seems to measure the same construct as KaTid-Child.
Conclusions Indications of gender differences in the sample call for further research. The results indicate that time processing ability can be seen as one construct in which time perception, orientation and management can be operationalized as different levels of complexity in time processing ability. Expressions of time processing ability differ at different ages. Thus, early intervention in time perception and time orientation may be needed to promote time management in later childhood. Professionals need to take time processing ability into consideration when meeting children who risk delayed development of daily time management.