The six concepts and research ethics

Which description best fits operationalising a variable?

Guidelines for research with animals ask researchers to reduce the number of animals used and to refine procedures to minimise harm. What is the third principle?

During a ten-minute observation, a researcher counts how many times each child shares a toy. What kind of data is this?

Turner et al. (2008) compared antidepressant trials registered with the US Food and Drug Administration with the trials published in journals. About 94% of the published trials appeared positive, but only about half of all registered trials were. Which bias does this show most directly?

Rosenthal and Fode (1963) told some students their rats were bred to be good at mazes and others that theirs were bred to be poor. The rats were in fact alike, yet the first group recorded better performance. Which control would best reduce this bias in later studies?

Maguire et al. (2000) found larger posterior hippocampi in London taxi drivers than in controls. Woollett and Maguire (2011) scanned trainee drivers before training and three to four years later. Why does the later design give stronger evidence that learning the city caused the difference?