Affiliation: | 1. New York University, Dept. of Teaching & Learning, 239 Greene St, #420, New York, NY 10003, USA;2. Hunter College, Dept. Curriculum and Teaching, 695 Park Ave., West 1103, New York, NY 10065, USA;3. Chegg Inc., 3990 Freedom Circle, Santa Clara, CA 95054, USA;4. Towson University, Dept. of Mathematics, 7800 York Rd., Rm. 356, Towson, MD 21252,USA |