In general, quantitative research seeks to understand the causal or correlational relationship between variable through testing hypotheses, whereas qualitative research seeks to understand a phenomenon with a real-world context through the use of interviews and observation.
When reviewing research that you have found, start by reading the abstract in order to identify the purpose of the study and the methodologies used. Research articles should also include a section that describes the methods used in more detail.
The table below illustrates the main differences between qualitative and quantitative research. Be aware that these are generalizations, and that not every research study or article will fit neatly into these categories.
| Qualitative | Quantitative | |
| Keywords | Complexity, contextual, inductive logic, discovery, exploration | Experiment, random assignment, causal/correlational, validity, deductive logic |
| Purpose | Understand a phenomenon | Discover causal relationships or describe a phenomenon |
| Sample | Purposive sample, small | Random sample, large |
| Data | Focus groups, interviews, field observation | Tests, surveys, questionnaires |
| Methods/Design | Phenomenological, grounded theory, ethnographic, case study, participatory research, clinical research | Experimental, descriptive, comparative, correlational |
Keep in mind that research articles are not always 100% qualitative or 100% quantitative. A mixed methods study involves both qualitative and quantitative approaches.