A close-up portrait photograph of Karen Spärck Jones. She is an older woman with short, wavy white hair and round, wire-rimmed glasses. She is smiling broadly and is looking off to the viewer's right. She wears a white collared shirt underneath a red jacket or blazer. The background is a plain, dark gray or black.
Karen Spärck Jones invented Inverse Document Frequency in 1972.
A foundational element in modern search engines, it provides the mathematical basis for determining which words in a search query are most important for retrieving relevant results. She died #OTD in 2007. #TechSky #WomenInSTEM