Development of the child’s ego strength scale: an observation-based assessment of the board game behaviors in play therapy in Korea

BACKGROUND: The purpose of this study was to develop a scale for assessing children’s ego strength through the observation of children playing board games in a therapeutic setting. Because ego strength is an index of psychosocial health, it is important to assess ego strength in childhood. In particular, children aged 7 to 9 exhibit their ego-strength characteristics in a situation challenged by self-competence due to their latency period. Therapists can identify such ego strength through game behaviors of children aged 7 to 9 in the play therapy setting. Thus, it is needed to develop a scale by selecting game play behaviors that grasp ego-strength. METHOD: Data were collected from 127 play therapists and play therapist-supervisors, who observed 468 play therapy sessions and 55 children aged 7–9 who received play therapy in Korea. The scale was created through content validity verification, factor analysis and verification of criterion-related validity. RESULTS: We generated a Child’s Ego Strength Scale (CESS) consisting of five sub-factors (Coping Strategy, Cognitive Strategy, Ego Restriction, Interpersonal Functioning, Frustration Tolerance) through exploratory factor analysis. The scale met the goodness of fit criteria in a confirmatory factor analysis. The analysis of therapy sessions of children with strong and weak ego strength, as identified by play therapists, showed a significant difference between the two groups in all five sub-variables. There was a significant correlation between the CESS scores and scores of ego strength-related variables of the Rorschach scale, indicating good criterion-related validity. CONCLUSION: The CESS appears to be a practical method for the assessment of ego strength in the field of child counseling. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13034-021-00369-3.