build Tool: Use a grading rubric
For a structured interview question, creating a grading rubric can help assess multiple candidates' answers and to fairly and consistently compare applicant responses.
For the attribute or quality the question is designed to test, Google often documents with illustrative examples what a poor, mixed, good, and excellent answer would cover.
Have interviewers take detailed notes of the responses. This allows the independent hiring committee to review and verify the assessments of the interviewers.