Innovator in Artificial Intelligence Created 'Pleasing' Pastel Portraits

A doctoral student of great focus and discipline, he specialized in mathematical logic at Massachusetts Institute of Technology from 1957 to 1962. There, he worked with some of the brightest minds in theoretical computer science and artificial intelligence, including Marvin Minsky and John McCarthy.

"Working with McCarthy and Minsky was no mean feat," Minker said. "He did very good work with them. He was in the forefront of history."

As a research assistant, Dr. Hodes took part in the pioneering work being done in the development of the computer programming language LISP, used in artificial intelligence research. He was one of the first people to recognize that logic could be used as a programming language.

After joining NIH's National Cancer Institute in 1966, Dr. Hodes worked on computer tools in biomedical applications, including developing software for online analysis of biomedical images.

One of his two patents included a method that allowed radiologists to calculate the dosage and location for treatment of tumors.

In the 1980s, the "Hodes clustering model" revolutionized how substances and other compounds were screened to treat cancer. His system helped scientists save the lives of thousands of mice that would no longer be needed in experiments, for which a Canadian humane society gave him a commendation.

As much as Dr. Hodes was a patient researcher and diligent mathematician, he also was a doting uncle who showered his nieces and nephews with attention, gifts and encouragement.

Gail Elizabeth Hodes Plotnik recalled her Uncle Louie buying her a telescope and sending her to an exclusive ballet camp. She remembers him as someone witha ready smile and a determination to do as much as he could. "If you talked to him, he probably felt it wasn't nearly enough [and that] maybe he could have done more."