Introduction
Interpersonal negotiation skills (INS) comprise actions used to solve social situations between interacting individuals involving different needs or desires. These abilities are part of one’s social competence and may be impaired in some psychiatric conditions. There are few validated psychometric tools for measuring INS in the literature. This pilot study aimed to investigate some basic psychometric properties of the Brazilian version of the Interpersonal Negotiation Strategies Interview (INSI) in children and adolescents.

Methods
We developed a new version of the INSI adapted to the Brazilian culture using eight different dilemmas in dyadic situations (with peers and adults), presented visually as drawings on cards. A group of psychologists and psychiatrists chose and adapted the dilemmas formerly proposed by the original version. The same scoring criteria as for the original instrument were used. A total of 20 children and adolescents were included in this pilot study. We investigated test reliability using measures of interrater reliability, test-retest, and internal consistency. The content validity of the INSI was also evaluated by comparison with scores from the Child Behavior Checklist-Revised (CBCL).

Results
Internal consistency and test-retest evaluations were acceptable (rater 1: α = 0.77; rater 2: α = 0.72); the reliability of the instrument was excellent (K = 0.078; intraclass correlation coefficient = 0.98; 95% confidence interval 0.97-0.99); and content validity was strongly significant (p < 0.001).

Conclusions
Preliminary results suggest that this version of the INSI has good interrater reliability and internal consistency and constitutes a promising tool to assess social competence.