AS Americans await breathlessly the coming of television-at-will and communications-on-demand, the flip side of this revolution goes almost unnoticed. The nation's increasing reliance on computers means it is vulnerable to electronic glitches.
Computer gremlins hassle shoppers. In a 1992 study of three retail chains in California, UCLA researchers found that bar-code scanners rang up the wrong price in 5 percent to 12 percent of the sales, usually overcharging.
They also upset car dealers. Chrysler Corporation recalled all its 1995 Neons earlier this month because a water leak in the computer system could cause the engine to stall.
They are sometimes lethal. On July 3, 1988, the USS Vincennes misidentified and shot down an Iranian airliner, killing 290 people, in part because of computer problems.
More often, they're just costly. In 1985, a software problem caused the Bank of New York to run up a $32 billion overdraft. The problem left several of the bank's customers in the lurch, not to mention the $5 million the bank had to shell out in interest charges.
``We have a lot of blind belief that computers are intrinsically good and a lot of examples where they are not,'' says Peter Neumann, principal scientist in the computer science laboratory at SRI International in Menlo Park, Calif. ``As we become more and more dependent, we tend to ignore that there are all these horrible modes of vulnerability.''
Computers are always becoming all fouled up, says Mr. Neumann, author of an upcoming book on the subject. The record stretches from space satellites that disappear to hospital machines with faulty software that have given patients huge doses of radiation with sometimes fatal results.
Computer scientists are divided on whether the situation is getting worse.
``We're no worse than we were five years ago and I think we're better off,'' says Jeff Huskamp, director of the MCNC North Carolina Supercomputing Center at Research Triangle Park.
Other experts believe man's increasing computer sophistication is not keeping up with the proliferation of computing.
``We have a lot of rocket scientists in our industry; what we don't have is a lot of people who exhibit common sense,'' says M. Arthur Gillis, author of ``Sorry, Our Computers are Down'' and 12 other computer-related books. ``They never ask: What if it doesn't work?''
Computers have been failing for some time now. On Oct. 5, 1960, computers attached to the United States early-warning radar system interpreted echoes from radar sensors as a massive Soviet missile attack. Actually, it was the rising moon that triggered the alarm, says Henry Walker, author of ``The Limits of Computing'' and professor of mathematics and computer science at Grinnell College in Grinnell, Iowa.
As software becomes more complicated, the potential for computer bugs increases. ``There are many examples of places where people are trying to solve extremely complicated problems and they can't think through all the things that can happen,'' he says. For example, a 1989 article in Datamation magazine praised the space shuttle's on-board software for having an exemplary error rate of only one error for every 10,000 lines of software code. But ``if you think about a program containing half a million lines of code, that would mean a code would still have 50 errors,'' Professor Walker says. In his view, that total is far too high.
``On the whole, the technology isn't that bad,'' says E. L. Quarantelli, research professor at the University of Delaware. ``It's the people running the technology that haven't thought through the problems that might arise.''
These problems are likely to become more apparent as the commercial world rushes to computerize. Already, attorneys are taking companies to court, claiming economic damages for faulty software. It even has a name: technology performance litigation.
``It has not grown as quickly as our dependence on the technology has grown,'' says Clyde Wilson Jr., a computer litigation specialist based in Sarasota, Fla.
Users are becoming more sophisticated. Computer hardware is much cheaper than it used to be, so users aren't wedded to million-dollar mainframe computers anymore. And more and more software programs are off-the-shelf solutions, which have been much more thoroughly tested than the custom programs common a decade ago.
Still, bugs continue to show up, even in commercial software. When Mr. Wilson's office upgraded to the latest version of WordPerfect 6.0, it found that computer files were becoming corrupted. When the company called WordPerfect's hotline, technicians admitted that, yes, the office had found a bug and that they hadn't yet found a solution.
But Wilson says he won't sue. ``I can keep it from doing serious damage,'' he says.