A<unk>  is an<unk>  that summarizes the current state of understanding on a topic. A<unk>  is generally considered a secondary source since it may analyze and discuss the method and conclusions in previously published studies. It resembles a survey<unk>  or, in news publishing, overview<unk> , which also surveys and summarizes previously published primary and secondary sources, instead of reporting new facts and results. Survey<unk> s are however considered tertiary sources, since they do not provide additional analysis and synthesis of new conclusions. Academic publications that specialize in<unk> s are known as<unk>  journals.<unk> s teach about: * the main people working in a field * recent major advances and discoveries * significant gaps in the research * current debates * ideas of where research might go next A meta-study sumarizes a large number of already published experimental or epidemiological studies and provides statistical analysis of their result.
Review article
Source document
Diagnosis-related group
Procedure code
Pharmacy research
Incident report
Montreal experiments
Expert report