stylistic:tone, quality:correction, linguistic:paraphrasing, information:extraction, quality:corruption
Four Levels of Learning Evaluation

Several authors have suggested an addition of a fifth level of evaluation. JJ Phillips has argued for the addition of a Return on Investment (ROI) level, which is essentially about comparing the fourth level of the standard model to the overall costs of training. Roger Kaufman has argued that ROI is essentially a Level 4 type of evaluation because it is still internal to the organization and that a fifth level of evaluation should focus on the impact of the organization on external clients and society.