This article presents a classification system for research methods in Psychology, previously published by the authors. The system is based on the logic of the research plan and is divided into three main groups: a) theoretical studies, b) empirical quantitative studies, and c) empirical qualitative studies. Theoretical studies include classical reviews and meta-analyses. Empirical quantitative studies include observational descriptive studies, survey descriptive studies, experiments, quasi-experiments, ex post facto studies, single-case experimental studies, and instrumental studies. Empirical qualitative studies include ethnography, case studies, and action research. The authors describe the main characteristics of each type and provide keys to identify their subtypes, illustrated with actual publications. The classification system is proposed as a model for research reports to be published in this journal. The authors emphasize the importance of precise information regarding the process of selecting participants and the need for careful data collection and analysis in qualitative studies. They also argue against including "mixed methods" in the first hierarchical level of the classification, as it is difficult to find studies that combine quantitative and qualitative designs. The authors also highlight the importance of using the correct label for studies to ensure the validity of the research and to allow for proper evaluation of the study's strengths and weaknesses. The classification system is intended to help researchers organize their work and to ensure that their research is properly understood and evaluated.This article presents a classification system for research methods in Psychology, previously published by the authors. The system is based on the logic of the research plan and is divided into three main groups: a) theoretical studies, b) empirical quantitative studies, and c) empirical qualitative studies. Theoretical studies include classical reviews and meta-analyses. Empirical quantitative studies include observational descriptive studies, survey descriptive studies, experiments, quasi-experiments, ex post facto studies, single-case experimental studies, and instrumental studies. Empirical qualitative studies include ethnography, case studies, and action research. The authors describe the main characteristics of each type and provide keys to identify their subtypes, illustrated with actual publications. The classification system is proposed as a model for research reports to be published in this journal. The authors emphasize the importance of precise information regarding the process of selecting participants and the need for careful data collection and analysis in qualitative studies. They also argue against including "mixed methods" in the first hierarchical level of the classification, as it is difficult to find studies that combine quantitative and qualitative designs. The authors also highlight the importance of using the correct label for studies to ensure the validity of the research and to allow for proper evaluation of the study's strengths and weaknesses. The classification system is intended to help researchers organize their work and to ensure that their research is properly understood and evaluated.