Tabla de Contenidos: “…Drawing valid inferences I: internal and external validity -- Drawing valid inferences II: construct and statistical conclusion validity -- Sources of artifact and bias -- Selection of the research problem and design -- Experimental research: group designs -- Control and comparison groups -- Assessing the impact of the experimental manipulation -- Observational research: case-control and cohort designs -- The case study and single-case research designs -- Evaluation of the single case in clinical work -- Qualitative research methods: an overview -- Assessment methods and strategies -- Assessment and evaluation of interventions -- Statistical methods of data evaluation -- Interpretation of the data -- Ethical issues and guidelines for research -- Publication and communication of research findings -- Closing comments: methodology in perspective.…”