This systematic review examines how instructional materials that embed errors (so-called 鈥渆rroneous examples鈥) or juxtapose incorrect and correct solutions (鈥渃ontrasting erroneous examples鈥) can influence student learning across a variety of domains (mathematics, medicine, science). The authors reviewed 40 studies and found that these approaches can enhance learning 鈥 especially by helping students grasp both what not to do (negative knowledge) and what to do (positive knowledge) 鈥 but the benefits depend strongly on how the errors are used, what scaffolding (prompts, feedback) is provided, how complex the task is, and how much prior knowledge the learner has.