^ I’m not saying that the “best” proxy is stats or that using scores alone would be my ideal approach.
The detailed NSSE surveys (perhaps combined with stats) would be closer to my ideal, but unfortunately they aren’t easily available for our purposes. I’m suggesting that even using a metric as simple and widely available as average SAT scores (perhaps combined w/class size … which you get from USNWR) may do at least as good a job of differentiating universities, w.r.t. instruction quality, as asking as few as ~60 students per school whether their professors are passionate, engaging, caring, and available. I’m thinking more in terms of the broad spectrum of research universities, not focused just on the USNWR top N (as you and @Greymeer seem to be).
I’m not surprised that LACs do consistently better on those questions. I’m also not convinced those questions are especially good at determining instruction quality. Still, if you’re finding that a set of selective LACs do consistently better on those questions than a set of similarly selective research universities - and if you do believe those 4 qualities are good indicators - then you may be on to something. At the very least, by aggregating the responses, you’re more likely to arrive at a representative sample size.