# Reliability of the Japanese Version of the Kit for Assessment of Time Processing Ability (KaTid)-Child in Typically Developing Children: A Pilot Study

## TL;DR

This pilot study validates the Japanese version of a tool for assessing time processing ability in children, showing it is reliable for typically developing children.

## Contribution

The study provides the first validation of the Japanese version of the KaTid-Child for use in typically developing children.

## Key findings

- Test-retest reliability showed moderate-to-strong correlations across four domains of time processing.
- Inter-rater reliability was perfect with kappa and ICC values of 1.00.
- The Japanese and Swedish versions showed high concordance for 8-10 year olds but differences in younger children.

## Abstract

Background: Children with developmental disabilities often experience difficulties in time management, which negatively affect their daily functioning and social adjustment. The Kit for Assessment of Time Processing Ability (KaTid) is a validated Swedish instrument for assessing time management skills. However, its use in Japan remains limited, and a culturally adapted version has not yet been validated.

Objective: This study aimed to validate the Japanese version of the KaTid-Child (KaTid-C-J) by examining its test-retest reliability, inter-rater reliability, and comparability of Time Processing Ability (TPA) scores with the developmental age bands of the original Swedish KaTid-Child.

Methods: Twelve typically developing children aged 5-10 years were recruited through snowball sampling. The KaTid-C-J was administered twice by the same examiner with an interval of 30-60 minutes to assess test-retest reliability. Video recordings were independently scored by another rater to assess inter-rater reliability. Spearman’s correlation, Bland-Altman plots, Cohen’s kappa, and intraclass correlation coefficients (ICCs) were used to examine reliability. Bootstrapping was performed to estimate 95% confidence intervals (CIs). Comparisons between the Japanese and Swedish versions were made using chi-squared tests.

Results: Test-retest reliability showed moderate-to-strong correlations (Spearman’s ρ = 0.531-0.872) across four domains of time processing (TP, TO/TC, TO/OT, TM), with no systematic or random errors. Inter-rater reliability was perfect, with both kappa and ICC values of 1.00. The Japanese and Swedish versions demonstrated high concordance for children aged 8-10 years; however, children aged 5-7 years showed slightly higher ability scores in the Japanese version, possibly due to linguistic and cultural differences in month-naming conventions.

Conclusions: The Japanese version of the KaTid-Child demonstrated high test-retest and inter-rater reliability, supporting its potential as a reliable tool for assessing time processing ability in typically developing Japanese children. Further studies with larger and more diverse samples are needed to confirm its validity and cross-cultural applicability.