Scientific and non-scientific approach; quantitative research (experimental and non-experimental research approach; paradigm, quantification, operationalization, variables); qualitative research (paradigm, objectives, strategies, unit of analysis); comparison of the characteristics of different approaches (weaknesses and strengths of each approach); necessary conditions for reliable causal inferences (factors that compromise the validity of certain types of conclusions); methods of data collection and data sources: survey, interview, questionnaire, checklist, content analysis, observation (systematic observation under natural conditions), focus groups, documentation, archive; sampling (probabilistic and non-probabilistic sampling); planning, organizing and conducting research.

compare data collection methods and data sources within qualitative and quantitative research approaches, assess the requirements for selecting suitable data collection techniques and analysis methods, assess the requirements for a valid scientific argument (assess the factors that contribute to or reduce the internal and external validity of the research), evaluate the quality of research designs within the qualitative and quantitative research approach in the investigation of problems in the field of social work, design a research plan for a selected problem from the field of social work,