Strengths: identify the ways in which a performance was of high quality and commendable. Each strength statement should address what was valuable in the performance, why this attribute is important, and how to reproduce this aspect of the performance.
(from Organization of the SII Report in 4.1.9 SII Method for Assessment Reporting)
What can easily be forgotten in the rush to get to Areas for Improvement, is that the purpose identifying strengths shouldn’t be primarily about affirming the performer. It isn’t a compliment or a thumbs up, though it can be phrased and taken that way. It is, instead, a way to capture the aspects of performance that should be reproduced in future performances. And beyond this, HOW to reproduce those aspects. If Areas for Improvement is about MAKING gains, then Strengths is about PRESERVING gains.