Tag Archives: Survey design

PMean: The perils of shortening a survey

Dear Professor Mean, I’m trying to publish a research study that involves some survey data, but the peer-reviewer is complaining about something I did. There was a scale that I used that had five items, but because the survey was already very long, I used only three of the five items. The peer reviewer seems to think that I arbitrarily chose these three items after looking at the data. How should I respond? Continue reading

PMean: A biased sample of car speeds

Dear Professor Mean, I read a newspaper report about speed limits and how few people obeyed them. A reporter decided to collect some hard data and drove exactly at the speed limit (55 mph in this particular setting). The reporter noticed that nine cars passed his car for every car that he passed, and concluded that most people are breaking the speed limit. I’m wondering if this is really a valid way to collect data. Continue reading