I complain about needless complexity in credit card agreements, telephone bills and government forms when it is a nuisance. Once in awhile, an example stops me in my tracks because it is much more serious. Reading the January, 2009 edition of Vanity Fair, I was horrified to read that unclear instructions had killed hundreds of people. On September 29, 2006, a Legacy 600 private jet caused an accident with a Boeing 737 in South America that killed everyone onboard the 737. I had heard about this accident in the news, but until I read the magazine article, I hadn't realized that unclear instructions and an unwieldy computerized Flight Management System were the roots of the accident.

Two pilots were flying a new but "inherently simple jet that had been stuffed with electronic capabilities-most of them nested, and therefore hidden from immediate view." As the Vanity Fair author points out, they were unable to answer the offhand question from a passenger who asked, "How much longer (to the destination)?" because the computer screen offered them:

"Duty time, Block time, Local time, Push time, Release time, Time Off, Time en Route, Time of Arrival, Fuel-Remaining Time, Void Time and Coordinated Universal time (aka Zulu time)."

Much more seriously-fatally for others-they had unknowingly turned off the TCAS transponder in mid-flight during their fumbling and searching. They had been flying on a collision course with the Boeing 737, yet they weren't transmitting their position so that collision-avoidance systems on the ground and other aircraft could detect them.

The overstuffing of functions in electronics is rampant, but when it occurs in trains, planes and automobiles, the result can be deadly. Let your mind wander to computer-guided robotic surgery and experiments with computerized anesthesia and you'll be sure to lose sleep.

There is a pervasive and dangerous acceptance that instructions must be thorough and that choices must be infinite. As a result, information that is exhaustive is frequently useless. Because an engineer can dream up a function doesn't mean it makes sense to add it.

What can we do about this? Complain. Send emails and letters to companies who issue unclear instructions telling them that you won't buy more from them because you couldn't understand how to use the last item you purchased from them. Companies have time and money to advertise products; equal attention needs to be paid to making sure we can use them after we buy them.

A few years ago, The European Union paved the way for consumers to seek refunds and even file lawsuits if they bought unassembled furniture and could not put it together based on the instructions provided by the seller. Until we, as buyers, users and citizens, declare unclear information unacceptable and dangerous, companies and legislators will continue to take the easy way out. Shorter, clearer writing is much harder to achieve than verbosity. Companies and government agencies must stop treating information as a label to be slapped on as a product or service goes out the door. Treated as an afterthought, rather than as an integral part of the development process, communication suffers.

However, there is an exception to every rule. There is one instruction writer we should thank. His unclear writing inadvertently saved lives. When police found the undetonated bomb that proved the Al-Qaida connection in the Madrid terrorist attack, they discovered that it didn't go off because the bomber programmed his cell phone alarm as the trigger for 7 pm rather than 7 am. For once, unclear instructions saved lives.

So when does life depend on clear instructions?-almost always.

Irene Etzkorn is the executive director, simplification for the Siegel+Gale New York office.