Which of the following objective measures would be least appropriate to use?

The least appropriate measure among the given options is the use of mother reports to complement child reports of depression. This is because mother reports introduce a level of subjectivity that could potentially bias the data. While parental input is valuable in many contexts, in matters concerning mental health, it's crucial to prioritize the child's self-reporting as this provides direct insights into their emotional state. Relying on mother reports may not fully capture the child's personal experience and feelings regarding their depression, which are essential for accurate assessment.

In contrast, teacher assessments, standardized test scores, and peer evaluations are largely designed to minimize bias and subjectivity. Teacher assessments often leverage structured criteria based on observed performance, standardized test scores provide quantifiable data on academic achievement, and peer evaluations can foster an understanding of collaboration and teamwork, benefiting from perspectives directly related to group interactions. Each of these measures has a defined methodology that enhances their objectivity compared to reports from a parent about their child's mental health.