When the Winter Olympics were on, my wife watched it devotedly.

But she also did social media and e-mail on her laptop at the same time.

"You're going to miss the performance," I said while figure skating was on.

"I can multitask," she said proudly.

A minute later a skater did a spectacular triple Lutz, but Amy missed it because she was looking at her computer screen and not at the TV screen.

This is yet another demonstration that multitasking is a bad idea and usually doesn't work.

A few times I wrote something on the PC while simultaneously talking on the phone.

Invariably, my concentration on the phone call waned, and before I knew it, I missed what the person was saying, which was uncomfortable and potentially embarrassing.

People who multitask think they are getting more done, but a growing body of psychology research indicates this is not true.

In particular, a 2001 study conducted by Joshua Rubinstein, Jeffrey Evans, and David Meyer found that multitasking reduces productivity as much as 40%.

The only multitasking that really works is when you do two activities at the same time and both are not demanding – for instance, mowing the lawn while listening to an educational lecture on your iPod.

I don't actually do that because I do not mow the lawn or own an iPod. But you get the idea.

I know a lot of subscribers will write to tell me that they are successful multitaskers. But unless you have measured your productivity and quality on a task (e.g., writing) with and without multitasking, I would argue that you don't know whether it serves you well.

As a youngster fresh out of college, I drove from the plant at Westinghouse into Baltimore to take marketing classes at Johns Hopkins.

I multitasked way back then when, in bumper-to-bumper traffic, I foolishly opened my textbook on my lap and read while driving. Result: several narrowly avoided fender benders and minimal retention of read material.

I am much more of a fan of sequential tasking: doing one project, and then when you tire of it, switching to something else.

I saw the rudest form of multitasking recently when I attended a lecture: many people in the audience were pecking away at their smart phone screens as the speaker talked.

This is discourteous as well as disconcerting to the speaker if he sees it. If you don't want to listen to the lecture, don't attend. Otherwise, eyes on the stage and phone in your pocket.