Well I just wanted to know in general, but in particular schools like case, tufts, bu, and temple. I guess these all give out tons of interviews!
Case- numbers school. You got high DAT, GPA- got invite. Your interview is rated and numbers plugged back in spreadsheet. When your total number is higher than arbitrary amount of points school decides to use you get acceptance Dec 1. Repeat as necessary until enough deposits to fill the class. Admission to such school is pretty straightworward process and appl with high stats have pretty good chance to be invited and accepted.
Some schools are not numbers schools. While they definetly appreciate appl with high stats, it is not enough by itself to grant interview or acceptance. Schools like UNC, Louisville clearly state on their admission pages they give your stats only 60 % of total weight and 40 % comes from PC, EC, interview etc. School like UOP accepts pretty much everyone they interview but to be choosen for their interview is another story.... This process appear more convoluted and that is when many people start saying "How come people with lower stats invited and I still did not hear anything from that school"...
I like last year description of one applicant to UF
"it is like adcom throws all aplications down the stairs and whichever falls on stair 1, 4 and 12 gets accepted"
There is no particular logic from applicant point but be sure that school does know what they doing. What we as applicants tend to forget that every DS has its TARGET audience. Many factors will come into play- does this appl has high stats and instate DS where he/ she very likely to be accepted? is this university our feeder school? Do we traditionally receive large amount of applicants from this area and they do tend to martriculate with us? do we have representation from this state? etc.
Regarding Tufts and BU- they both schools that interview late, have large pool of applicants- 4,000+ each and interview 400+ appl, fewer pre Dec, more post Dec. Acceptance rate 60- 70 %, higher for pre Dec dropping down as times goes. Generally most March interviews will be for alternate/ waitlist although some years they had 10- 15 spots open.