research types

Randomized controlled trial (RCT)

Participants are randomly assigned to intervention or control to test causality

Case study

In-depth analysis of a single subject, case, or event

Case series

Observational report describing characteristics or outcomes from multiple similar cases

Cohort study

Observes groups with shared characteristics over time to study risk or disease

Cross-sectional study

Gathers data at a single point in time to analyze prevalence or correlations

Case-control study

Compared people with a condition (cases) to those without (controls), retrospectively

Meta-analysis

Uses statistical methods to combine results from multiple studies into one conclusion

Systematic review

Comprehensive review of literature with strict methods to minimize bias

Qualitative Research

Uses open-ended methods like interviews to explore meaning or lived experiences

Descriptive study

Observed and describes trends or patterns without inferring cause and effects

Experimental research

Manipulated variables to establish cause-effect relationship

Quasi-experimental research

lacks randomization but includes intervention and control comparison

Longitudinal study

Data is collected over an extended time period from the same participants

Survey research

Collects self-reported data from a population using questionnaires or interviews

Mixed methods

Combines qualitative and quantitative research methods in a single study

Retrospective study

Looks backwards in time using existing records to examine exposures and outcomes

Prospective study

Follows participants forward in time to monitor outcomes after exposure