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3-D equipment gives school lessons an added dimension


Vera Johnson's fifth-graders barely noticed as visitors walked into their classroom this week. They were far too focused on the disembodied head that seemed to float in the front of the room.

Suddenly a human ear, with all its innards exposed, jumped out at them.


The kids were responding to a relatively new kind of technology just starting to filter into North Texas classrooms: a 3-D projection system, coupled with interactive, computer-driven content.

In her class at Richardson ISD's Hamilton Park Pacesetter Magnet elementary school, Johnson was teaching a lesson about the human senses. Down the hall, Brittany Russo gave her third-grade class a tour of the solar system. The sun, planets and asteroids spun gently like an animated chandelier. Russo "grabbed" a comet and took the class on a virtual ride though an orbit, all the while engaging her students in a spirited question-and-answer session.

Both teachers were part of a pilot program coordinated last school year by DLP, a division of Texas Instruments that produces hardware for this kind of 3-D projection. This week, both teachers welcomed the technology back into their classrooms.

"My struggling students don't give up," Russo said. "It's almost impossible for them to stop paying attention."

The pilot program is putting projectors and content into eight public school districts in five states. In Texas, it's being used by schools in Richardson and Dickinson, near Houston, as well as Tarrant County College. Early studies indicate kids taught with the technology learn some particularly challenging lessons faster and better, company officials and teachers say, though not all education experts are convinced.

TI also provided the equipment for the Shelton School, a private school in Far North Dallas that specializes in children with learning difficulties, including dyslexia and attention-deficit disorder.

The floating head was too distracting and confusing for her sixth-graders, teacher Laurent Sanders said. But a visually simple 3-D math simulation was effective in helping teach about computing the volume of irregularly shaped objects. Volume is a concept that challenges many kids with standard learning abilities, as well.

In the 3-D lesson, "floating" stacked polygons could be rotated and separated and filled with color, demonstrating how each contributed to the whole. Sanders did an informal test, using her standard lesson with one class and the 3-D projector with another. The kids who had the 3-D lesson asked better questions and caught on faster, she said. Then she showed the 3-D lesson to the first class. One girl raised her hand with a comment:

"Why didn't you just show us this in the first place?"

The teachers at Hamilton Park reported similar results. They tested kids before and after the lessons. Students who had the 3-D experience showed greater understanding of the material, the teachers said. While none of these experiments were sophisticated enough to be conclusive, all of the teachers were confident the 3-D lessons helped.

How it works

Whether it's tech-generated images or the real world, human 3-D perception works the same way. Each eye transmits a slightly different "flat" image into the brain, where the two pictures are processed into what we experience as depth.

For theater-style 3-D, two projectors simultaneously flash images onto a special screen. To see the 3-D image, viewers must wear polarized glasses that allow only one of the images into each eye. The projector and screen are relatively expensive - tens of thousands of dollars for a theater model - and the glasses relatively cheap.

The TI-style technology works differently. The two images are flashed through one projector onto a standard screen. But the visual stream is cut up into bits only one-120th of a second long. A bit for the left eye is followed by a bit for the right eye, over and over. Special glasses are synchronized with the projector and alternately block the vision in each eye for one-120th of a second at a time - far too fast for people to notice.

As far as the brain is concerned, it's getting two simultaneous images that it combines to produce the 3-D perception. And so the disembodied head "floats" in the front of the classroom.

The projector costs about the same as many other school-ready models - less than $800 - and can be used for showing 2-D content. Several companies make 3-D-ready projectors. But the fancy electronic "shutter glasses" aren't cheap - more than $75 each.

Is classroom 3-D worth the money? The answer isn't entirely clear.

The technology used in the pilot has several special features: The visuals are sharp and engaging. The lessons that have been designed for the 3-D equipment are unusually interactive, allowing teachers much more control than is the case with any film or even many computer-based lessons. For the solar system and human senses lessons, for instance, teachers were able to quickly adjust the display based on students' response.

Would it work as well if it just looked like 3-D, the way many computer design programs or modern video games create seemingly solid forms on a 2-D screen? Researchers admit they don't know for sure.

Cost question

Count Thomas Reeves as a skeptic. He is professor emeritus in the University of Georgia's department of educational psychology and instructional technology. He started researching educational technology in the early 1970s, and he's seen many ballyhooed gadgets fail to pan out in the classroom.

Though he did not witness the TI display, his educated guess is that the 3-D-ness of the lessons didn't make a huge difference. But maybe it's one of many tools that might work in the right classroom, he said.

"I think that in the hands of a stimulating teacher who can provide the proper give-and-take, a tool like this could be useful," he said. "But is the cost of it justified?"

During the two classes in Hamilton Park, several kids were obviously responding to the 3-D effects, reaching out almost unconsciously to "touch" images. And the teachers think the whole package pulls students in. Most of the students go to 3-D movies, so the school displays need to keep up, the teachers say.

"It keeps their attention, and brings what's going on outside into school," Johnson said.

That's what the TI folks want to hear. The hardware and content for the pilot project are being donated by the companies involved. If demand goes up, they anticipate more content will be produced and the cost of the special glasses will start to drop. And schools, the firms hope, will eventually be willing to pay.

The teachers, however, warned not to put too much emphasis on 3-D.

"It will get old really quickly," the Shelton School's Sanders said. "It needs to become just an additional tool."

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