Transplanting reference books onto CD-ROM produces some winners, some losers. The Multimedia Encyclopedia of Science Fiction (*** out of four, CD for Mac and Windows PCs, Grolier, about $50 in stores) falls in the middle.

This multimedia version goes beyond its analog predecessor, the Hugo Award-winning Encyclopedia of Science Fiction by Peter Nicholls and John Clute, by adding about 20 videos and 30 audio interviews.

The entries cover nearly 1,800 authors, more than 200 sci-fi themes (androids to virtual reality), popular movies (even trailers for some, including The War of the Worlds) and 300 or so summaries of classics such as Ray Bradbury's Martian Chronicles and Frank Herbert's Dune.

Searching can be done alphabetically, just as you might leaf through the book. To better understand the genre, click through the Time Machine, a time line of real-world events and science-fiction milestones starting with Thomas More's Utopia written in the early 1500s. Browsing through the entries and clicking when one catches your fancy make for fun excursions, too.

Only some of the videos add to the experience. Those based on topics like time travel and life-forms won't enlighten devotees. Videos starring well-known authors work much better, especially the one with Bruce Sterling (author of the Hacker Crackdown) and Frederik Pohl (Gateway) expounding on cyberspace and virtual reality.

Overall, this disk doesn't give life to any strange new worlds, but it will probably energize many to set out in search of books that do.