Resumen
Objectives Mindfulness consists of paying attention to the present moment with curiosity, acceptance and non-judgment.
Although several instruments exist for evaluating mindfulness in adults, few have been adapted for children, and even fewer
have been adapted to the Basque language. The aim of the present study is to adapt the Reduced Kentucky Inventory of
Mindfulness Skills (KIMS-R) questionnaire for use with Basque-speaking children.
Method A total of 479 children from the last 2 years of primary education (Years 5 and 6), aged between 9 and 12 years,
participated in this study. The sample was divided into two subgroups: exploratory subsample (n = 237) and confirmatory
subsample (n = 242). In addition to the KIMS-R, we also administered other questionnaires to measure mindfulness, per-
ceived stress, emotional skills, neuroticism and depression.
Results The analysis showed that the adapted questionnaire was reliable, with scores measuring consistency and stability in
acceptable ranges. The analysis revealed a 5-factor structure (Internal observation, External observation, Description, Acting
with awareness and Acceptance without judgment). These dimensions showed acceptable internal consistency (α between
0.69 and 0.83; ω between 0.69 and 0.83) and temporal stability (r = 0.54, 0.64, 0.79, 0.40, 0.59). The instrument was also
found to have adequate external validity, with associations being observed between mindfulness and emotional abilities,
perceived stress, neuroticism and depression.
Conclusions The Basque version of the KIMS-R will enable scholars to assess the ability of children in the Basque Autono-
mous Community to be mindful. It will also be useful for evaluating the effectiveness of interventions designed to promote
mindfulness skills. This adaptation of the KIMS-R instrument can be considered a step forward in the field of mindfulness
research.
Preregistration This study is not preregistered.