In many rural areas of India, schoolchildren use chalk to write on handheld, erasable black slate tablets roughly the size of a piece of paper, because their teachers lack the funding or electrical infrastructure for anything more sophisticated. A group of humanitarians and educators are trying to change this by developing a new type of solar-powered LED tablet, called the I-slate, that uses a stylus rather than chalk and features a special chip that uses up to 30 times less electricity than a standard computer chip.

Although it sounds counterintuitive, particularly in an educational setting, the I-slate's brain—its information processing chip—is expected to conserve energy by using probabilistic logic, which provides answers to calculations that are rounded rather than precise. (Most chips rely on Boolean logic in their circuits to ensure computers will perform calculations with the utmost precision). These probabilistic chips aren't lazy; they do just enough work to get the job done.

"It's a system of design that factors in human thinking," where the mind is able to fill in the blanks even when it isn't given all of the information available, Krishna Palem, a Rice University computing professor and head of the I-slate project, said yesterday at a panel discussion in New York City commemorating the Institute of Electrical and Electronics Engineers' (IEEE) 125th anniversary. As an example, one of the slides in Palem's presentation included the question, "CAN YOU USTNNDERAD THIS STNECNEE?" The goal is to use the human brain's capacity for interpretation to help in the design of less expensive technology, he added.

Chips in most computers, cell phones and other electronics are made using complementary metal-oxide semiconductor (CMOS) technology. But  the I-slate (which would be roughly the same size as its  chalk counterpart) would use a probabilistic version called probabilistic complementary metal-oxide semiconductor (PCMOS). PCMOS chips are expected to be best suited for applications such as powering the I-slate's display or running streaming video on small screens (such as a cell phone), where picture clarity isn't as important as the message itself.

Palem and his team, which includes doctoral candidate Lakshmi Chakrapani (who helped him develop the system's probabilistic logic), are working with the International Institute of Information Technology (IIIT) in Hyderabad, India, to develop a visually based mathematics curriculum that allows children to learn by doing, regardless of their grade level or whether they have a full-time teacher. Rice and IIIT (working with the Indian nonprofit Villages in Development and Learning Foundation) hope to begin testing prototype I-slates within a year in classrooms in southern India's Mahboobnagar District.

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