Table 2 Three levels of research
| Â | Level of research | ||
|---|---|---|---|
Primary | Secondarya | Tertiary | |
Research | Empirical study: research based directly on observation, experiment, or simulation rather than on reasoning or theory alone [26, 47]. | Systematic review: collation and interpretation of existing empirical studies using systematic and explicit methods [48]. | Review of reviews: collation and interpretation of existing systematic reviews [48]. |
Types of research | Qualitative study: research that aims at exploring and understanding phenomena in terms of the meanings people bring to them [49, 50]. | Qualitative review: review combining qualitative studies. | Review of qualitative reviews: review combining qualitative reviews. |
Quantitative study: research that aims at testing theories by examining the relationship among variables [49]. | Quantitative review: review combining quantitative studies. | Review of quantitative reviews: review combining quantitative reviews. | |
Mixed methods study: research involving collecting and integrating both quantitative and qualitative data [49]. | Mixed studies review: review combining qualitative, quantitative, and/or mixed methods studies. | Review of mixed studies reviews: review combining mixed studies reviews. | |
Data | Primary data collected from fieldwork or lab work. | Findings from included studies. | Findings from included reviews. |
Data analysis | Analysis: a step within empirical study of investigating, making sense of, interpreting, and/or theorizing primary data using statistical and/or text analysis procedures [49, 51]. | Synthesis: a step within a systematic review consisting of creating something new of findings from included studies [48]. | Synthesis of findings across included reviews. |