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Research design. A research design is the "blue print" of the study.

Research design

The design of a study defines the study type (descriptive, correlational, semi-experimental, experimental, review, meta-analytic) and sub-type (e.g., descriptive-longitudinal case study), research question, hypotheses, independent and dependent variables, experimental design, and, if applicable, data collection methods and a statistical analysis plan. Research design is the framework that has been created to seek answers to research questions. Design types and sub-types[edit] There are many ways to classify research designs, but sometimes the distinction is artificial and other times different designs are combined.

Nonetheless, the list below offers a number of useful distinctions between possible research designs.[1] Grouping[edit] Confirmatory versus exploratory research[edit] Confirmatory research tests a priori hypotheses—outcome predictions that are made before the measurement phase begins. State problems versus process problems[edit] Case study. This article is about the method of doing research.

Case study

For the teaching method, see Case method. For the method of teaching law, see Casebook method. For reports of clinical cases, see Case report. For the Case Study (1969) film series by Lockheed Aircraft Corporation, see propaganda film. Case-control study. Case-Control Study vs.

Case-control study

Cohort on a Timeline A case-control study is a type of study design used widely, originally developed in epidemiology, although its use has also been advocated for the social sciences.[1][2] It is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case-control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have that condition/disease (the "cases") with patients who do not have the condition/disease but are otherwise similar (the "controls").[3] They require fewer resources but provide less evidence for causal inference than a randomized controlled trial.

Field experiment. A field experiment applies the scientific method to experimentally examine an intervention in the real world (or as many experimentalists like to say, naturally occurring environments) rather than in the laboratory.

Field experiment

Field experiments, like lab experiments, generally randomize subjects (or other sampling units) into treatment and control groups and compare outcomes between these groups. Field experiments are so named in order to draw a contrast with laboratory experiments, which enforce scientific control by testing a hypothesis in the artificial and highly controlled setting of a laboratory. Often used in the social sciences, and especially in economic analyses of education and health interventions, field experiments have the advantage that outcomes are observed in a natural setting rather than in a contrived laboratory environment.

For this reason, field experiments are sometimes seen as having higher external validity than laboratory experiments. Examples include: Experiment. Even very young children perform rudimentary experiments in order to learn about the world.


An experiment is an orderly procedure carried out with the goal of verifying, refuting, or establishing the validity of a hypothesis. Controlled experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Controlled experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results.

There also exist natural experimental studies. A child may carry out basic experiments to understand the nature of gravity, while teams of scientists may take years of systematic investigation to advance the understanding of a phenomenon. Overview[edit] In the scientific method, an experiment is an empirical method that arbitrates between competing models or hypotheses.[1][2] Experimentation is also used to test existing theories or new hypotheses in order to support them or disprove them.[3][4] Literature review. A literature review is a text of a scholarly paper, which includes the current knowledge including substantive findings, as well as theoretical and methodological contributions to a particular topic.

Literature review

Literature reviews use secondary sources, and do not report new or original experimental work.[1] Types of Literature Reviews[edit] Most often associated with academic-oriented literature, such as a thesis, dissertation or peer-reviewed journal article, a literature review usually precedes the methodology and results section. Literature reviews are also common in a research proposal or prospectus (the document that is approved before a student formally begins a dissertation or thesis). Its main goals are to situate the current study within the body of literature and to provide context for the particular reader. Distinguishing between Process and Product[edit] A careful literature review is usually 15 to 30 pages and could be longer. Meta-analysis. In statistics, meta-analysis comprises statistical methods for contrasting and combining results from different studies, in the hope of identifying patterns among study results, sources of disagreement among those results, or other interesting relationships that may come to light in the context of multiple studies.[1] Meta-analysis can be thought of as "conducting research about previous research.


" In its simplest form, meta-analysis is done by identifying a common statistical measure that is shared between studies, such as effect size or p-value, and calculating a weighted average of that common measure. This weighting is usually related to the sample sizes of the individual studies, although it can also include other factors, such as study quality.