The document describes the development of the Simulated Colonoscopy Objective Performance Evaluation (S.C.O.P.E.) tool, which is a non-virtual reality simulation for assessing endoscopic skills. Four tasks were created to evaluate core skills: scope manipulation, tool targeting, loop management, and mucosal inspection. A study of 35 subjects stratified into novice, intermediate and expert groups found that experts outperformed intermediates, who outperformed novices, on all four tasks and the total S.C.O.P.E. score, demonstrating the tool's ability to differentiate skill levels. This provides initial validity evidence for S.C.O.P.E. as an objective assessment of endoscopic skills.