Which type of review is considered the most formal?

The type of review considered the most formal is the inspection. Inspections are structured processes that follow a defined set of procedures and involve multiple participants, including stakeholders who may not be directly involved in the work being reviewed. This process is characterized by pre-defined roles, a documented process, and a focus on finding defects in the work product. Inspections typically require specific documentation and can involve a checklist to ensure all aspects are covered, which enhances their rigor and formality.

In contrast to inspections, other review types, such as technical reviews and walkthroughs, while they follow some structure, do not match the level of formality and rigor associated with inspections. Informal peer reviews, on the other hand, are characterized by their lack of formal procedures and documentation, making them the least formal among review types. Thus, inspections stand out as the most formal method, aimed at achieving a high level of quality assurance in the reviewed material.