ESSEN, Germany -- How you interact with your computer is all- important. It can mean the difference between getting your work done quickly and spending a lot of time in frustration.

That's why the most important interface between man and machine is the input device. For most users, a keyboard and mouse are old friends on the computer table.

But an input device long familiar in the graphics world is finally gaining the attention it deserves: The graphics tablet. In a nutshell, this peripheral lets you use a stylus to input information.

In principle, a graphics tablet functions like a piece of paper upon which a stylus is moved. The difference is that the drawing or writing shows up on the computer screen, not on the surface of the tablet itself.

Unlike touch pads and touch screens, which sense contact between the stylus and the tablet, graphics pads carry a signal from the stylus to the tablet. The tablet then transfers that signal to the computer, which converts the signal into a representative movement on the computer screen.

Graphics tablets are also pressure-sensitive, meaning they reflect to the computer how much pressure is applied to the tablet by the stylus that you hold in your hand. Press down firmly, and a thicker line will appear on screen.

Among many professional computer users, especially graphics professionals, graphics tablets are already standard equipment.

Designers and graphic artists swear by them.

The use of a stylus is the most precise possible interface with a computer, says Thomas Hofmann, a scientific worker at the Institute for Ergonomics and Design Research at the University of Essen, in Germany.

Professional-grade devices, offered by manufacturers such as Genius, Aiptek, or Wacom, can cost several hundred dollars, but smaller, high-quality ones are also available for general use. The rule of thumb when buying graphics tablets is that the bigger the tablet, the more it will cost.

While professionals can get devices in sizes as large as a standard piece of paper, home users should find the smaller devices well suited for text or image manipulation.

Some are available for as little as 50 dollars.

Yet very few non-professional computer users own the devices. "There's still a lot of potential for the home computer market," says Wacom's Sabine Mende.

Mende recommends graphics tablets for any users who perform diverse tasks on their computers. Industrial designer Thomas Hofman sees graphics tablets as worthwhile from an ergonomic point of view, offering a chance to switch between typing on the keyboard and writing using the stylus, DPA reported.

Making the switch is no problem: studies have shown that computer neophytes become comfortable with stylus and graphics tablets quickly. Directing the cursor, selecting objects, and writing and dropping data are easy with a graphics tablet -- and more natural than using a mouse, once you know how it's done.

Research has shown that children also take readily to graphics tablets, and they love tablets for using drawing programs, Hofmann says. Studies have shown that children who rely upon a mouse and keyboard at the computer at a very early age can suffer weaknesses in writing and gross motor skills. Use of a graphics table might, by contrast, encourage handwriting skills in children.

Graphics tablets do have drawbacks, of course. "It bothers me that the 'page' is separated from the output device," says Andreas Prions, a European industrial designer. Prions has plenty of professional experience with tablets.

Ergonomics expert Hofmann also sees this as a negative. "The eye of untrained users constantly switches between the tablet and the monitor when you're drawing something," he says.

This is less than optimal from an ergonomic standpoint.

Tablet manufacturers are working on a solution to this problem already. Wacom, for example, offers a device dubbed "Cintiq" that is both monitor and graphics tablet.

While the model stands as an important milestone in the graphics tablet's development, it also reflects just how much the devices are still aimed at the pros. The Cintiq can cost several thousand dollars, depending upon size.