Margaret Raymond and Eric Hanushek respond: The assertion that "archival time-series analysis" is second in quality only to a true controlled experiment
That Project STAR was a controlled experiment
has been widely recognized by educational researchers, sociologists, economists, and statisticians, including the distinguished Frederick Mosteller, who wrote that STAR was "a controlled experiment
which is one of the most important educational investigations ever carried out.
Gilliam and Iyengar employ a complex, controlled experiment
, supplemented by a probability telephone survey, to explore the connection.
A controlled experiment
is in progress to identify the impacts of an oil spill on a coastal salt marsh and to evaluate in situ biological remediation techniques to help restore the environment.
The controlled experiment
took place in the late 1940s and early 50s in at least four Indian residential schools, documents in the National Archives reveal.
That would be a true, controlled experiment
, says Stumpf, where any effect measured could only be due to the one variable that was changed.
Scientists have just completed the first controlled experiment
validating one of folk medicine's favorite treatment: eating yogurt can prevent vaginal yeast infections.
Empiricism is the systematic study of natural phenomena by direct observation and controlled experiment
Training Guide on the Controlled Experiment
in Social Research.
She thinks that designing a controlled experiment
will give researchers a better understanding of the factors affecting IVF outcome, rather than just analyzing statistics.
According to the Atlantic, a new study by market-research firm called Qualtrics, working with public-opinion shop Evolving Strategies, did a controlled experiment
testing the reactions of independent and persuadable voters to ads from Romney, Obama, and a Republican super PAC.
He said: "We support a controlled experiment
providing information to parents whose children are being targeted by paedophiles.