(FORTUNE Magazine) – -- In the ''information richness'' studies that Vanderbilt professor Richard Daft conducts, employees invariably say that face-to-face communication with management and fellow employees is preferable to other modes. Respondents do give reasonably high marks to some high-tech gadgetry, but as Daft notes, such tools work best if the users have already met in person. Herewith the pros and cons of communications whiz-bangery:

VOICE MAIL Pros. Because of the short time allowed to leave a message, people learn to be focused in what they say, observes San Francisco consultant Bert Decker. -- Helps companies reduce expenses and improve productivity. Dennis Vohs, chairman of Ross Systems, which makes application software for computers, estimates that his Octel voice-mail system saves the company $2 million a year in travel and secretarial expenses. For a user with 1,000 employees, an average system costs $110,000; for one employing 30,000, about $1.75 million. Most companies say the money saved covers the cost of the system within one year. Cons. Employees, secretaries in particular, can overuse voice mail. When a secretary is busy or away from her desk, she often transfers her calls to a colleague who may have shifted his calls. ''Customers get irritated with too many forwards,'' notes Union Pacific's Walsh.

VIDEOCASSETTE Pros. It can cost as little as a few thousand dollars to make a ten-minute corporate video. % Cons. Fear of the camera. Executives must spend time and money for training to overcome this fear. -- It is one-way and provides no chance for feedback.

VIDEOCONFERENCING Via digital transmission Pros. Increases productivity and decreases travel budgets. ''We no longer lose two or three days of work when employees fly from New York City to Los Angeles for a two-hour meeting,'' says H. Mitchell Watson Jr., chief executive of ROLM Co., which has headquarters on both coasts. -- High-quality reception. -- Interactive and easy to operate, especially systems like PictureTel's Model 200, which allows zooming in or out for a better view. As many as eight sites can participate, though only the one speaking is displayed at any time. -- Increasingly affordable. The average cost for a videoconference system is $50,000, down from $90,000 four years ago. Coast-to-coast transmissions that once cost as much as $1,200 an hour can now cost as little as $30 an hour. Cons. The picture can be slightly jittery.

Via satellite transmission Pros. Can reach remote areas where telephone companies have not yet installed fiber-optic networks to transmit digital signals for videoconferencing. -- Executives can choose one-way, two-way, or even 16-way conferencing. Most, like Walsh of Union Pacific, use one-way satellite transmission to communicate with large numbers of employees at multiple locations simultaneously. Cons. A two-way system is fairly expensive. Market-leader Hughes charges about $56,000 to set up the transmission, and hardware costs another $45,000 or so. As your usage increases, your dollar-per-hour cost decreases.