In a controlled experiment, researchers meticulously manipulate one or more variables to determine their effect on another ...

Welcome back to our series of articles sponsored by Intel – “Ask a Data Scientist.” Once a week you’ll see reader submitted questions of varying levels of technical detail answered by a practicing ...

Jonathan Freeman, Donald A. Goldmann and John E. McGowan, Jr. Most information in hospital epidemiology comes from observational studies of hospitalized patients, not from planned experiments. Data ...

Unmeasured confounding variables are a common problem in drawing causal inferences in observational studies. A theorem is given which in certain circumstances allows the researcher to draw conclusions ...