I am learning a lot this week at the Third European DOE User meeting in Lucerne, which features many excellent applications of DOE to industrial problems. Here’s an interesting observation from Pavel Nesladek, a technical expert from the Advanced Mask Technology Center of Dresden, Germany. He encounters severe pressure to find answers in minimal time at the least possible cost. Pavel found that whatever number of runs he asked to do for a given design of experiment, his manager would press for fewer. However, he learned that by asking for a prime number, these questions would be preempted, presumably because this seemed to be so precise that it must not be tampered with! For example, Pavel really needed to complete 20 runs for adequate power and resolution in a troubleshooting experiment, so he asked for 23 and got it. Tricky! Perhaps you stats-savvy readers who need a certain sample size to accomplish your objective might try this approach. Prima!