"Context: Code review is a fundamental, yet expensive, part of software engineering. Therefore, research on understanding code review and on how to improve reviewers performance is paramount.

Objective: We aim to test whether there is an effect of a guidance approach on review effectiveness and efficiency. This relationship is expected to work through lowering the cognitive load of the task; therefore, we analyze the mediation relationship as well.

Method: To test our hypotheses, we employ an experimental design where professional developers with little review experience have to perform three code review tasks. We use three conditions: no guidance, a checklist, and an explicit review strategy. Furthermore, we measure the reviewers� cognitive load.

Limitations: The main limitations of this study concern the specific cohort of participants, the mono-operation bias for the guidance conditions, and the generalizability to other changes and defects."