Human interaction with machine translation takes three basic forms: evaluation, revision and use. This chapter focuses on the cognitive complexities of the first two forms, i.e. evaluation and revision. Evaluation is considered from the perspective of human and automatic evaluation. Human evaluation can take the form of error annotation, adequacy or fluency measurement or ranking. Automatic evaluation focuses primarily on similarity measures. All of these forms of evaluation are problematized from a cognitive processing perspective. The process of revision, or post-editing, is also considered from a cognitive perspective. It is demonstrated that this is a complex cognitive process, which, to be properly understood, needs to be examined through a dynamical and situated embodied cognitive lens.