A model is a data management, production and transfer system organized in explanatory trends of past, current and future relationships. The emphasis on each suggests decision making and strategy execution. The objective of this work was to specify a model for of the perception of utility. An exploratory and cross-sectional study was conducted with a selection of 186 students from a public university in central Mexico, considering their participation in the system of professional practices and social service in local organizations. The validity of the instrument that found a one-dimensional variable that explained 43% of the variance was established, but the research design limited the results to the research scenario, suggesting the extension of the work.

Objective. Social historical reconstruction of the Ayotzinapa case from the perspective of Social Work intervention models. Methodology. Mixed, a qualitative, retrospective and hermeneutical study with key informants and other quantitative, cross-sectional and correlational research with an intentional selection of mobilization activists in favor of Ayotzinapa. Results. Disclosure of meanings from discourses and narratives of causal attribution of responsibility to the State for the enforced disappearance and genocide of 43 students, as well as relationships that determine the expectations of justice based on the expectations of honesty. Conclusion. The intersection device corresponds to a qualitative and quantitative diagnosis of the social representations of the Ayotzinapa case spread as a central axis of a public agenda.

Meta-analytic studies are distinguished by comparing literature that reports positive effects with respect to literature that warns of spurious or negative effects. The aim of the present work was to establish the proportion of probabilities between categories and subcategories extracted from the consulted, updated and specialized literature. A documentary study was carried out with a selection of sources indexed to international repositories such as Copernicus, Dialnet, Ebsco, Latindex, Redalyc, Scielo. An indistinct scenario was found, even though the literature that reports positive effects on the quality of life and the subjective well-being of public health services prevails; suggesting the extension of the work to repositories like WoS and Scopus.