[1] In the study of finite geometry, she introduced the concept of the complement of an oval,[2] and her work with Rita Zemach on orthogonal arrays of strength four was described as "the first significant progress" on the subject.
Although she planned a teaching career with the master's degree she earned, her instructors provided support to continue her studies for another year.
However, her interest in mathematics diminished as she became involved in the paramilitary Haganah and then worked in the Red Cross during World War II.
At the end of the war, Seiden came to work for the Palestine Census of Industry and began studying statistics under Aryeh Dvoretzky.
[1][4] On the recommendation of Tarski, she entered graduate study in statistics at the University of California, Berkeley in 1947 as an assistant to Jerzy Neyman.