Which quality in a recommendatory letter is most impactful for an application?

A recommendatory letter that highlights validated experience and personal insights carries significant weight in an application because it provides specific, concrete examples of a candidate's skills and accomplishments. This kind of detail assures the reader of the writer's genuine assessment of the individual. Personal insights allow the recommender to illustrate how the applicant has demonstrated particular strengths or overcome challenges, thereby showing a deeper understanding of the applicant’s character and capabilities.

In contrast, flattery and unnecessary praise often lack substance and can be perceived as insincere, thus failing to offer meaningful insight into the applicant's qualifications. Generic comments do not differentiate the candidate from others and often render the letter ineffective since they do not provide sufficient evidence of the individual’s unique contributions. Brief and concise criticism, while potentially useful, is generally less impactful in a recommendatory letter, which should focus on positive attributes rather than negative feedback. Overall, letters that present validated experience and personal insights provide the strongest endorsement of an applicant’s potential.