Browse the glossary:

• random
  — By chance, not predictable; … (read more)
• random allocation (randomization, random selection)
  — The process of assigning participants in a study to treatment comparison groups using a chance process, like drawing lots, to protect against bias.; … (read more)
• randomization, stratified see stratified randomization (stratification, stratified allocation)
  — The process of assigning participants in a study to treatment comparison groups based on characteristics (strata) thought to affect their prognosis; … (read more)
• randomized study (randomized control trial, RCT, randomized trial, randomized controlled trial (should not be used))
  — A category of studies comparing two or more treatments in which random allocation is used to assign participants to treatment comparison groups; … (read more)
• recruitment
  — The process of persuading people to join a group or study.; … (read more)
• reference standard test (gold standard, reference test)
  — The best available method of determining whether people have a condition; … (read more)
• regulation of research
  — Processes used to assess whether proposed research is scientifically defensible, ethical, and worthwhile; … (read more)
• relative effect
  — The ratio of outcome measures in one treatment comparison group compared to another in a study; … (read more)
• reliability
  — The extent to which a claim or evidence about a treatment effect is trustworthy; … (read more)
• repeated measures study
  — A type of non-randomized study, similar to an interrupted time series study, in which outcomes are measured in the same participants at multiple time points; … (read more)
• reporting bias (publication bias)
  — Bias resulting from decisions by researchers, or others (e.g. drug companies or journal editors) not to report or publish the results of a study, or not to provide full information about a study; … (read more)
• reproducibility (repeatability, replicability)
  — The extent to which the results of studies are confirmed in the results of subsequent studies; … (read more)
• research
  — The use of systematic and explicit methods to address questions; … (read more)
• research data (empirical data, empirical evidence)
  — Information gathered in studies to help address research questions, such as assessing treatment effects; … (read more)
• research evidence (research findings, research results)
  — The findings of studies, including systematic reviews; … (read more)
• research methods (methods)
  — The systematic and transparent steps and protocols researchers follow to address research questions; … (read more)
• research priorities
  — Research projects selected as particularly deserving of support; … (read more)
• resource use
  — In treatment comparisons, all the important items and people used to deliver a treatment, and which may differ between the treatment comparison groups in a study; … (read more)
• risk of bias
  — The likelihood of there being a systematic error (bias) that distorts an effect estimate in treatment comparisons.; … (read more)
• risk ratio (RR, relative risk)
  — The likelihood of an outcome in one treatment comparison group divided by the likelihood in another; … (read more)