Dorothea B. Marsden, M.Ed., is a nationally-known early childhood educator, trainer, and developer of assessments for preschool and school-age children. She was originally a teacher of preschoolers and then on the Faculty at Tufts University's Eliot Pearson Department of Child Study for 16 years. She worked with Dr. Samuel Meisels developing the Early Screening Inventory and continued to help write and standardize the several revisions. She helped design and then direct several innovative high quality early childhood programs in Massachusetts and Vermont. She is also one of the primary authors and developers of both the Work Sampling System and the Ounce Scale, observational assessments for children birth through age 8.