Sampling design and case study in the formation of the sport detraining competence

Abstract

This article describes and analyzes the transition from a census design to a case study, and evaluates its impact on the validity and transferability of the results. The methodological problem arises in an emerging normative context that drastically reduced student enrollment. A mixed paradigm with qualitative predominance is assumed, non-experimental, structured in three stages. The first (diagnosis, 2022-2023) uses a population census of 25 students and all the teachers who attended them in practice. The second (design and validation, 2023-2024) uses intentional sampling to select 16 experts through the Delphi method. The third (pilot, 2025-2026) assumes a collective and instrumental case study based on a census of the context: the 7 students and all available tutors and advisors, due to the institutional reduction derived from the 2022 National Career Meeting. Theoretical, empirical, and statistical methods are applied. Expert criteria validate the proposal (W=0.976; p<0.001). The case study documented that in Investigative Labor Practice I, 71.4% of students reached the competent condition, while in Investigative Labor Practice II, 85.7% consolidated and transferred the competence. It is concluded that the sampling design is pertinent: the transition to the case study guarantees internal validity through triangulation and confirmability, and ensures the analytical transferability of the findings to other similar formative contexts.