I made a speech to a group of physicians and health professionals at Emory University the other day. When the time came for questions, I knew exactly what to expect.

I always do.

Whether I'm talking to Boy Scouts or to my middle-aged and older buddies who belong to the SeniorNet computing club, I can depend on the same basic questions from any audience. My answers to these questions aren't always what you'd expect. Since these questions are so common, and my answers are not, we'll tackle some of them today.

People love to rate things, so I'm often asked for an opinion on whether desktop computers are better than laptops; whether Macs are better than PCs; or whether a specific model of Dell computer is better than another Dell.

Trouble is, imagine if someone asked you to decide among a truck, a convertible or a fuel-efficient hybrid car. Your choice would depend on how you planned to use it.

If you need to haul things, a two-seater sports car would be a poor choice. If you drive hundreds of miles each day, a car that sips instead of guzzles is a good choice.

It's the same with high-tech purchases. The way to make a good one --- whether you're shopping for a computer, software or an HDTV --- is to start by defining the problem you are trying to solve. Once you do that, it's easy to figure out the best technology.

If you start by deciding that you travel a lot and need to check e-mail from hotel rooms, you arrive at the decision that you need a battery-powered computer.

The point is this: You don't have to be a computer expert to make intelligent decisions when it comes to buying a gadget. Instead of thinking in terms of brands and advertising claims, start with your own needs, your own problems.

What if you can't come up with a problem to solve? Then you don't need the new gadget.

Some other questions:

> How safe am I when I am online?

The truth is that you're about as safe as you are in the rest of your life. That is, not very safe. You're not safe driving to work. Nor is your information safe in that plastic mailbox on the street in front of your house.

There's also the danger that someone will hack into your computer and steal your credit information. Even worse, as has happened several times recently, the giant database companies that store your information aren't always able to guard it in an effective way.

So take all the precautions you can when working online. But then go ahead with your life.

Keep in mind that you're as safe buying a book online as you are when you hand your credit card to the server at a restaurant. Don't let the real worries about security make you stop eating at restaurants or buying books online.

> Should I get my high-speed Internet service over cable, or is DSL best?

In theory, cable modems are faster than DSL. In practice, unless you download digital copies of feature-length movies, you probably won't notice much difference. If you're moving from a dial-up connection, what you'll really notice --- with either --- is that the Web is more fun to use when you don't spend a lot of time waiting.

So when it comes to high-speed access, shop based on price, convenience and the reputation for technical support of the high-speed providers in your area.

The "in your area" part of my answer is important. Don't worry about national reputations. A company can have great people in one part of the country, duds in another. So instead, ask your neighbors about their experiences.

> What's the best way to buy a computer: online, retail store, small mom-and-pop store, or from a guy I met in the alley last week?

Don't buy from the guy in the alley. Otherwise, buy from the place that offers the best price for the computer you need.

It's really no different from the way you should shop for a car. First, come up with the specifications you want or need as far as processor speed, amount of RAM, size of hard disk, etc. Use them to price brand-name computers at retail stores, online and in mall shops.

Once you're close to making a decision, use www.google .com and type in the name of the seller and the term "customer service." If you find a long list of complaints, rinse and repeat with your second favorite computer.

Those are some of the questions I get. But this is my favorite. It came from an earnest woman in the back row: "What's that interesting design on your shirt?"

My answer: "Mashed potatoes with a little gravy."

tecbud@ajc.com