Students in the intervention group received one hour of training on pain by the same researcher, using a 3D-printed pain biochemical activity model.

Students in the control group received one hour of training on pain by the same researcher, using face-to-face instruction and PowerPoint presentations. To avoid interaction between the two laboratories, the control group received training first, followed immediately by the intervention group, who were then transferred to the other laboratory.

Computer-generated drawings designed to explain the biochemical mechanism of pain were created using plastic filaments from a 3D printer. Students were divided into small groups of nine using the resulting figures, and the processes of pain mechanisms were explained. At the end of the session, the figures were fixed by applying epoxy resin. After the students poured the epoxy resin onto the models in liquid form, it solidified within six hours, securing the shape as a transparent layer.

This form including students' age, gender, high school type, native language, whether they choose a career voluntarily, and whether they have received previous training on pain.

The Pain Mechanism Information Form was developed by the researchers based on literature. The developed questionnaire consists of 14 items, each prepared in a short-answer and fill-in-the-blank format. The scope of the Pain Mechanism Information Form includes: Pain physiology and classification, structure of nociceptors and pain transmission pathways, chemical mediators (Bradykinin, Prostaglandin, Serotonin, CGRP, Substance-P, Histamine), peripheral nerve ending release and mast cell activation, and vascular effects of inflammation (vasodilation, edema).

Five experts were consulted to ensure the validity of the Pain Mechanism Information Form. Each item was reviewed for its appropriateness and clarity for the intended learning outcomes and content, and necessary revisions were made based on the expert opinions. To ensure reliability, scoring was assessed for short-answer tests, and the questionnaires were scored separately by two raters. The inter-rater reliability coefficient (Cohen'

This scale was developed by Tugtekin and Dursun (2022) to measure motivation related to the instructional materials used. It is a one-dimensional, 14-item, 5-point Likert-type self-report scale. High scores on the scale indicate high motivation. The Cronbach's alpha internal consistency coefficient for the measurement tool in this study was determined to be 0.942. Item-total correlation values ranged from 0.629 to 0.820. Permission for use of the scale was obtained from the author via email.