I was reading this article from BusinessWeek.com titled Gateway to Better Hiring and I enjoyed this test that the author incorporated into her employment ad.
Here is an example. I was hiring an editor, and so I included this instruction in the job ad: “If you are interested in this job, please write to me at this e-mail address with your comments on the most recent edition of our newsletter.” (I included the URL for the newsletter, of course.) That is a simple enough gate. Curious to know what percentage of candidates followed the instruction? Ten percent. The rest probably never saw the instruction at all, “buried” as it was in a 100-word job posting. They just spotted the job ad, read maybe the first line, and shot off a résumée. (sic)
That 90% aren’t in my pool. I saved time, and the best candidates rose right to the top.
She goes on to suggest a writing assignment for candidates to get a glimpse of their writing ability and grammar. This task is one we use in our sourcing activities and it is quite effective. One other piece of information you learn is their responsiveness to your request. Some respond fairly quickly while others ignore the request all together. Some respond poorly while others respond in thought-provoking ways.
On your next round of candidates, ask them to analyze part of your business, address a market question or explain a finely-worded topic. You will be surprised at what you learn from such a simple exercise.