ONE afternoon last week I found myself sitting at a desk that was not mine, answering to a name that was not mine, and fielding phone calls and e-mail messages from colleagues who don’t exist. I held a “meeting” with an actor pretending to be a passive-aggressive employee who was sabotaging a new sales plan with his vocal disapproval. I had a “conference call” with an actress who was convincingly frosty as she refused to share key research and manpower that her department had and mine needed. In other words, I spent that day doing what a growing number of employees will do if they are to reach a position of power or potential: I was being “assessed.”

Most evaluations are not nearly this elaborate and consist of answering true/false questions on screen or with pen and ink, rather than a full day of role playing. But the purpose is the same.

There are 2,500 profiling “instruments,” (oddly, the word test is never used by those in the testing business), and every year, companies seem to rely on them more when deciding to hire or promote. Sixty-five percent of the companies surveyed reported their use in 2006, up from 34 percent of companies a year earlier, according to Staffing Industry Report, a human-resources newsletter.

The reasons for this growth have little to do with the content of tests themselves, because that has stayed more or less the same for three decades. What has changed, instead, is the workplace.