Rick Nelson

Test is useless—for people, not chips
November 30, 2006

Testing is useless—at least when it comes to screening people for medical conditions. That’s the premise of Darshak Sanghavi, a pediatric cardiologist, writing in Slate. Medical tests, he contends, result in false positives and unnecessary treatment that can do more harm than good.

Sanghavi cites as an example a random test at an airport that correctly identifies 99 percent of cocaine smugglers and correctly excludes 99 percent of nonsmugglers. “Assume about 100 smugglers enter an airport of 100,000 passengers. Among smugglers, 99 would have a positive test, and one would be negative. But among law-abiding travelers, 999 would have false-positive tests. Thus, only 99 out of 1,098 people who test positive, or less than 10 percent, are real smugglers. So, a lot of innocent people endure fruitless internal body-cavity searches. If all you care about is catching smugglers, the results are great, since only one escapes. But if you focus on the harm to bystanders, the screening procedure seems pretty draconian.”

Does this apply to the electronics industry? Before you throughout your test equipment, keep in mind that false positives are less of a problem for chips and circuit boards. Certainly, the industry wants to reduce the false-positive (false fail) problem, but it’s nowhere near as significant as in the medical industry. Chips and boards don’t suffer physical and emotional stress from false positives—the worst case is “no fault found” after additional diagnosis.

Posted by Rick Nelson on November 30, 2006 | Comments (0)