Some notes: SBG was introduced in Algebra II as a mid-year experiment; in 2011 and 2012 I gave a one time test of basic skills at the beginning of the year in Pre Cal before the SBG style tests began. In 2012 I gave fewer Pre Cal tests because, ironically, Texas toyed with the notion of increased standardized testing: 15 exams required to graduate high school. We administered benchmarks and real versions of all those tests that school year, in addition to the previous slate of tests still required for the class of 2013. That summer they retracted the plan after public outcry.
I allow about 40 minutes for each test. They happen every 7-10 calendar days. What I think is missing from Frank's numbers is a considering of that old stand by the quiz. Usually at least two quizzes accompany those three term tests, and take about 20 minutes each. Also, it is more common for schools here to have six terms per year. Estimate 15 tests and 12 quizzes per school year and you get about 14 hours, excluding the final.
My Opinion vs Student Opinion
If you ask my students, a lot of them would tell you we test a lot. In the case of testing successive Fridays, that's when many will moan "didn't we just have one?" If you ask the right followup questions, you can get them to see beyond the gut reaction. Do we have quizzes? No. Do you have more grades? Yes. Do you know more about how you're doing? Yes. Do you have homework on top of all of this? No.
I have had them interviewed before, year after year, lots of feel like they have a more specific idea about how they're doing. They can misfire on one part of an assessment but celebrate success on another and come out feeling like they learned. They can share heartbreak over coming oh so close to that elusive 4.
Are these test high stakes? I don't think so. My students get nervous about them, sure. They THINK it's life or death (thanks grade culture). Some of them really push themselves to get double 4s as much as possible. A lot are ready to have a shot at improving something that didn't go well previously. How do I know they aren't high stakes? I have watched the data for years. The standard 15 unit tests allows 15 attempts at 15 test grades. My students have over 80 attempts at 40 test grades. One misunderstood topic in the mix doesn't make a dent.
At the end of some grading terms, topic 7 or 8 might make a 1 point difference. Nobody fails a grading term for an isolated problem, it takes a series of miscues. At I've noticed the problem long before it's ever actually a problem.
I think a better question is: what are you getting from your 14 hours?