The goal of this observational study is to develop a questionnaire to assess a child's concept of pain and to evaluate its psychometric properties in schoolchildren aged 8-17 years. The main question[s] it aims to answer are:

• Validate to Spanish language the Conceptualization of Pain Questionnaire to assess a child's concept of pain.
• Conduct an analysis to evaluate its psychometric properties. Participants will respond a questionnaire of 15 items and asks respondents to respond if they believe the items/statements to be true or false, although they are allowed to respond undecided.

The inclusion criteria were: to be able to read and write in Spanish language and excluded if they suffered from an intellectual disability that, according to the teachers, could interfere with their participation in the study procedures.

The main outcome was: The Conceptualization of Pain Questionnaire - Spanish version.

Inclusion Criteria:

• Were able to read and write in Spanish

Exclusion Criteria:

• If they suffered from an intellectual disability that, according to the teachers, could interfere with their participation in the study procedures.

Schoolchildren aged 8-17 years.