Bob Cohen, a long-time marketing and media research executive who served as president of Scarborough Research from 1993-2009, died Saturday. He was 58. Cohen also served as president of the Market Research Consortium, chair of the Council of American Survey Research Organizations, and was a member of the board of directors of Marketing Research Institute International. Prior to Scarborough, he was a top executive at Yankelovich Partners and The Los Angeles Times, and other companies.