BURIED in a pile of long-discarded floppy disks were the very first versions of "Reader Rabbit" and "Where in the World Is Carmen Sandiego?" A computer-savvy 5-year-old girl ("I'm almost 6!") sniffed in dismissal of the crude graphics and tinny sound quality. "Reader Rabbit" will celebrate its 10th anniversary this summer, and "Carmen" came out in 1985.

The young reviewer's comments seemed harsh about two of the classic programs that started the revolution in educational software, but compared with today's multimedia offerings her assessment is valid.

Most of the new programs discussed here are for children 3 to 7 years old, but older students and adults might enjoy some packages. A major caveat: Increased sophistication and quality usually means a more powerful computer is needed to run them.

Most programs require significant hard-disk space, a monitor capable of displaying enhanced graphics and a sound card. A software program retailing for $39 might not work unless several hundred dollars in hardware is added. A CD-ROM drive is becoming a strongly recommended option because many of the better programs are being released on CD-ROM.

"Thinkin' Things": This Edmark program is a marvel of smooth integration of all the elements needed to engage a youngster 4 to 9 and provide a rich educational supplement. The program has six activities that try to stimulate a child in various cognitive areas.

In one, Oranga Banga is a hip, simian musician who plays percussion instruments for a child to repeat in sequence. Oranga shouts out a cheery "Groovy!" after a successful completion, and a reassuring "Why don't you try that again?" follows a miss. The program also allows the student to make up a tune using drums, cymbals, chimes, triangle, gong or block. The sequence is recorded and can be played back instantly. The waterfowl Toony Loon does the same thing as Oranga but with a xylophone that changes its bars into other musical shapes, such as rubber bands, wine glasses and even squawking chickens.

Feathered Friends teaches pattern-matching by having a child assemble cartoon birds in a factory. Several birds are already assembled in a pattern; the child must pick the right shoes, body, hat and color to fill in the next pattern. Teaching Motion

Flying Shapes and Flying Spheres teach depth perception, motion and spatial relationships. Each shape bounces around the screen in a pattern the child sets, and makes a distinctive sound when it hits the edge of the screen. The sounds range from laughter to water gurgling down a drain.

In the Fripple Shop, the student operates a pet store selling Fripples. A customer either comes to the shop, calls on the phone or faxes an order for a Fripple with certain characteristics -- such as curly hair, spots, but not small eyes. If the child picks out the Fripple with those characteristics from several pictured on the shelf, it bounces out of the store, with appropriate sound effects, into a delivery van.

Thinkin' Things comes in Macintosh and MS-DOS versions. Both retail for $59.95.

"The Backyard": Broderbund has a deserved reputation as a leader in the field of learning software for children. The runaway success of its "Carmen Sandiego" series, with spinoffs into formats as diverse as a live-action television program and a Saturday-morning cartoon series, is not a fluke.

"The Backyard" is the third installment of the exploration programs, which include "The Playroom" and "The Treehouse." The program lets a child explore the backyard by clicking on objects and interacting with them. Some objects react immediately; others take the player to a different level.

With a click on the dirt in the garden, the hose sprays water and plants sprout. One click on the hole in the picnic table drops the player into an animated board game and a competition against a robot named Bongo Bot.

There are some familiar characters in "The Backyard." Pepper Mouse from "The Playroom" is one of the guides. The other guide is a new character named Ginger Mouse. In both "The Treehouse" and "The Backyard," the child has the option of picking a female or male character as a guide. "The Backyard" also has an original song, played at the beginning of the program.

"The Backyard" is available for about $35 in the DOS/Windows and Macintosh versions.

"SimCity 2000": When Will Wright designed a "game" that couldn't be won, didn't have a time limit or shootouts with aliens, used minimal hand/eye coordination and involved planning a city, most computer-industry insiders scoffed. But Maxis's "SimCity" became not only a hit but also an addiction and a requirement in several urban planning courses.

The newest "SimCity" version is "SimCity 2000." It is a major jump in sophistication and complexity, which is amazing in a program that was already sophisticated and complex. Designing and maintaining a city is a task that exercises all the mental muscles.

While this is clearly a program for older students and adults, the 6-year-old Deputy Mayor had lots to contribute. "Dad, you can't put houses there; it's too far from the power plant." She was right. An additional power plant had to be built, at a cost of $6,000. Taxes had to be raised to pay for it.

The Mac and DOS version retails for $69.95; a Windows version is to be released soon.

CD-ROM's: The large amount of space on CD-ROM disks enables programmers to add rich sounds, videos and near-movie-quality animation. The price war in the computer industry has made CD-ROM drives affordable. Encyclopedias have proved very well suited to the format; here are updates on three of the more interesting and useful ones:

The 1994 editions of "Microsoft's Encarta," "Compton's Interactive Encyclopedia" and "Grolier's Multimedia Encyclopedia" are notable for changes in the way they look and are operated (the interface, in computer jargon), and for the addition of more video and sounds.

"Encarta" has made the most startling changes. The 1993 version set a standard in electronic encyclopedias. Others were based on a printed version, and used much of the same information. Though "Encarta" was based on the text of Funk and Wagnall's, the visual aids and a large portion of the text were specially commissioned.

A standout feature is its "Find Wizards." The wizards ask a number of questions about what information is desired, conduct a search and present the user with a list of relevant articles. One can search by subject, discipline (such as biology) or time line, pictures, video or audio.

And all is not serious. "Encarta's" system contains a multimedia trivia game called Mind Maze that can entertain and infuriate for hours.

Compton's program has lowered its price to $149.95 (the original retail price was $395). "Encarta" costs $139.95 (also down from $395). Grolier's system lists at $395, but has a special price of $149 for first-time buyers. All three encyclopedia are available in Macintosh and Windows versions.

Photo: Toony Loon, a character from the "Thinkin' Things" software program by Edmark. (Edmark Corporation)