What type of review is not based on a formal documented procedure?

An informal review is characterized by its lack of a formal documented procedure. This type of review typically involves casual discussions among team members about a piece of work, such as code, test cases, or other artifacts. Participants may provide feedback based on their expertise or experience without adhering to strict guidelines or checklists that are common in formal reviews. The focus of an informal review is often to share knowledge and perspectives in a relaxed manner, fostering collaboration rather than strictly evaluating compliance to defined standards or processes.

In contrast, technical reviews, formal reviews, and systematic reviews follow structured procedures with specific roles, documentation, and criteria for evaluation. They are more formalized processes designed to ensure a thorough examination of work and adherence to requirements. This distinction makes the informal review stand out as the option that does not rely on formal documentation or defined procedures.