Quantitative research studies produce results that can be used to describe or note numerical changes in measurable characteristics of a population of interest; generalize to other, similar situations; provide explanations of predictions; and explain causal relationships. Quantitative methods depend on the design of the study (experimental, quasi-experimental, non-experimental). Study design takes into account all those elements that surround the plan for the investigation, such as research question or problem statement, research objectives, operational definitions, scope of inferences to be made, assumptions and limitations of the study, independent and dependent variables, treatment and controls, instrumentation, systematic data collection actions, statistical analysis, time lines, and reporting procedures.
Adapted from: Salkind, N. J. (2010). Encyclopedia of research design (Vols. 1-0). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412961288
Data mining
The process of discovering useful patterns in very large databases. Methods from statistics, machine learning, and database management are used to restructure and analyze data in way that permit knowledge of information to be extracted from the material.
Experimental design
Experiments are ways of assessing causal relationships by randomly allocating "subjects" to two groups, then comparing one group (the control group, in which no changes are made) with the other group (the test group, who are subjected to some manipulation or stimulus).
Health data
Data about the health of individuals or populations, primarily gathered when people interact with health care systems.
Psychometrics
The application of mathematical principles to the measurement of psychological constructs.
Structured observation
A method of collecting observational data through the use of pre-coded schedules which allow the presence, frequency, and duration of prespecified actions, behaviors, or occurrences to be recorded in a systematic way.
Survey research
A method that involves asking a sample of people a set of per-prepared questions on a single occasion in order to gather data about their opinions and behavior.
Definitions are from Sage Research Methods' Methods Map.
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