<p>Duke, Vanderbilt, Emory, and Wash U are in many ways quite similar to Northwestern, but I don’t think the OP’s 30% admit rate cutoff is totally off-base. Duke is probably harder to get into than Northwestern, while Vandy and Wash U are probably similar or only slightly easier. Emory has a 29% admit rate–close enough that I’d include it.</p>
<p>These schools have several things in common with Northwestern: medium-sized private research universities with strong academics, low s/f ratios, and secular, i.e., neither affiliated with nor influenced by any particular religious denomination at this point in their institutional histories.</p>
<p>Another feature of NU that was striking to me and my D2 when we visited there last summer was that Greek life is very strong, with 32% of male students in fraternities and 38% of females in sororities. That was a big turn-off to my daughter and I’m no fan of it myself, but some people find it a positive. IMO whenever you get that much Greek presence, it starts to dominate campus social life and becomes a defining characteristic of the school. In that respect, too, Duke (29% M, 42% F), Vandy (35% M, 50% F), Wash U (25% M, 25% F), and Emory (29% M, 33% F) are quite similar to Northwestern.</p>
<p>At a slightly less selective level (>30% admit rate) but still with strong academics, Wake Forest (35% M, 50% F), Lehigh (38% M, 39% F), RPI (21% M, 16% F) and Case Western (28% M, 31% F) all fit the model of small-to-midsize, private, secular research universities with low s/f ratios and a very active Greek presence.</p>
<p>Among the larger LACs, Colgate (32% M, 29% F) and Bucknell (43% M, 48% F) are quite similar in all respects but size.</p>
<p>Now if you’re looking for “similar” in particular academic programs, that’s another matter. In engineering, for example, I’d say Cornell, Michigan, Illinois, Wisconsin, Purdue, and Carnegie Mellon are most similar, but most of these schools are in other crucial respects more different than similar.</p>