Research methodology: Study types

Different study designs are popular within research fields, and sufficient knowledge of study types may help you to design your research methodology. Different types of studies refer to various methods for obtaining data, i.e., information researchers collect depends on their goals, and the questions they're trying to answer. This simply means that several study types can answer the study question, but what is the best? There are two main categories of studies; observational and experimental. Observational studies involve collecting and reviewing data in a non-invasive way (literature review, meta-analysis, and systematic review). Experimental studies vary widely but always involve the researchers designing a study with certain variables (inclusion and exclusion criteria), interventions (exposure), and intentional data points (outcomes). Researchers pick the best preferable study type to answer their research question or hypothesis. For instance, when researchers want to know available data on a certain topic, they may choose an observational approach to write review articles, or design an experimental study (randomized controlled, case-control, cohort, and cross-sectional study) to write original articles. The present editorial aims to clarify the important differences between the experimental study types to select the best study design answering the study question.