THE MYTH OF MULTITASKING: HOW "DOING IT ALL" GETS NOTHING DONE, by Dave Crenshaw, Jossey-Bass, 138 pages, $19.95.

Dave Crenshaw, a business coach for CEOs, is a graduate of Brigham Young University's School of Management. In this candid and satirical little book, he takes on one of the most talked about social myths of the modern scene — multitasking.

Using an anecdotal approach, Crenshaw tells stories about executives with the key phrase being that "multitasking is a lie. The truth is that multitasking is neither a reality nor is it efficient," writes Crenshaw, acting the role of a business executive lecturing an employee who prides herself on her ability to do many things at the same time.

Crenshaw quotes the conclusion of a study conducted at the University of California at Irvine, saying, "Eleven is the average number of minutes an employee can devote to a project before being interrupted."

To buttress that statement, Crenshaw includes another from Rene Marois, a Vanderbilt University psychologist, who said, "Our research offers neurological evidence that the brain cannot effectively do two things at once."

In Crenshaw's fictional account of a business owner trying to teach a CEO that she is not really multitasking, she gives him an example of continuing to answer her e-mails even while a secretary comes in and asks her a question. The owner asserts that she was not multitasking at all — but switchtasking.

As a result, she lost time, maybe five minutes — and she did both tasks with lower quality. The author adds Suze Orman, a prominent business author, saying that multitasking is "the absolute ruination of the perfection of a project."

Finally, the author concludes that the CEO in his example lost on average 28 percent of the workday due to interruptions and inefficiencies — with multitasking or switchtasking being responsible.

According to one study, two hours are lost per person through interruptions during a 40-hour work week. Another researcher concluded that $650 billion is lost to the U.S. economy due to interruptions just like these.

Crenshaw asserts that multitasking became popular toward the end of the 20th century as a way of justifying the chaos most of us face on a daily basis. We simply turned it to our advantage, thinking that multitasking is a good thing. He quotes the Wikipedia definition of multitasking as "the apparent simultaneous performance of two or more tasks by a computer's central processing unit."

The key word is "apparent."