If the Adversity Score had been used as a threshold check on applications it would have a very large effect.
As you said, the score for Sidwell Friends was 3, and if applied to the SAT score it would have reduced a student’s measured score by 212 points.
For contrast, the school where my son attends (Klamath Union high school, in OR) had an adversity score of 81 and the SAT would have been boosted by 120 points. That’s a huge deal.
Now, the Landscape scores are used differently in the sense that there’s not a single adjustment score added to the SAT, and it’s very opaque how they’re actually applied to actual application consideration processes. Given the number of applications selective schools receive, I figure they do use some sort of mechanical screening process. The Landscape does produce a 1 to 100 “score” for (I believe) both the high school and the neighborhood in which the student lives. It’s not hard to imagine that being used to screen applicants with decent GPA/SAT but coming from poor areas who might receive some extra attention.
In general, the Adversity/Landscape benefits rich applicants from poor areas over poor applicants from rich areas, because it doesn’t look at the student so much as where they live.
That said, having moved from suburban NY/DC to rural Oregon, a student who wants to succeed academically here faces REAL challenges – few/no truly advanced classes, all the issues that come with low-income schools (disruption, low expectations of students, etc). So getting a boost from Landscape isn’t a freebie…