Relationship between Student-Faculty Ratio and actual class sizes?

That is true tk, but those 5% criteria add up an eventually make a difference since very little separates universities from one another. The rest of the faculty resources rank is not much better. It is still self reported, and since universities are lying about student to faculty ratios, I do not trust the rest of the outputs.

With respect to the OP’s questions, probably the most important thing to understand about S:F ratios is that they do not represent average class sizes.This would be true even if every college calculated the ratio in exactly the same way. The reason is that the S:F ratio doesn’t account for how professors spend their time.

Williams College reports a 7:1 ratio. Berkeley reports a 17:1 ratio. Even assuming they use the same calculation methods, does this mean that Berkeley undergraduate classes typically have 2-3 times as many students as Williams classes? Not necessarily. In some popular lower-division courses, the one at Berkeley may be more than 3x larger than a similar course at a LAC. Lecture class enrollments may be 10X or 20X the number expressed in the S:F ratio … or even higher. In some less-popular upper-division courses, there may not be much difference at all in enrollments at the two schools.

So again, if you really care about class sizes, it’s a good idea to look up enrollments for the ones you care about most. If you think that is too tedious, look at the class size distribution numbers in the Common Data Sets (section I) or on the US News site (under “academic life”). However, keep in mind that at some big research universities, a large number of upper division courses with low enrollments may be inflating the percentage of “small” (< 20 student) classes and deflating the percentage of “big” (>= 50 student) classes. The percentage of time you spend in large lecture classes, especially during your fist 2 years, may be higher than any of these numbers lead you to believe.

No one statistic (or 2 or 10 for that matter) will give you a full picture.
I think F:S ratio is important to note, but also how many ‘instructional’ faculty (vs research, administrative) are FT vs PT, and how many ‘instructional’ grad students there are. These provide additional clues as to the faculty resources and their priorities.

(And then there’s the all-important 4-year graduation rate, which is probably more telling than anything…)

Compare the S:F ratios listed on Newsweek and the ones listed for the Times (https://www.timeshighereducation.com/world-university-rankings) which has an excellent vetting system-getting rid of non-teaching faculty (whereas nonteaching faculty are included in other ranking system. Then the schools have to sign off on the numbers-a lot more accurate! I know of one school that has an absurd student faculty ratio on Newsweek but is simply off the charts on the Times ranking-and the off the charts ratio is consistent with this schools shortage of staff and resources. I think the Times ranking reflects available resources accurately.

lostaccount, I’m not sure what exactly you’re seeing that makes you think the Times ranking accounts for instructional resources better than other rankings do.

Here’s the Times Caltech entry:
https://www.timeshighereducation.com/world-university-rankings/california-institute-technology?ranking-dataset=133819

The Times entry reports the same S:F ratio (3:1) that the CDS reports in section I2 (and which Alexandre challenges in post #18, above). The ratio of graduate plus undergraduate students to “professorial faculty” would be about 7:1 (2181 to 300), which may be what the Times is trying to express in its “Student:Staff Ratio” (“6.9”). The “3:1” ratio appears to express the ratio of undergraduate students to “professorial faculty”.

The CDS, section I1, defines “instructional faculty”. For 2014-15, Caltech shows 330 full time and 25 part-time instructional faculty. I assume the Times is pulling its numbers from the CDS. I’d be surprised if it has devised its own vetting system to separate teaching from non-teaching staff.

This is also a marketing tool. Schools like to boast about low faculty:student ratios to depict a possible level of intimacy and accessibility.

But this means ZERO if you, the student, aren’t the type to engage instructors, go to office hours or glean the benefit. You could attend a school with at 1:1 ratio – but if you’re too shy or arrogant to go to office hours or speak w/the instructor after/before classes – it’s a waste.

IMHO: it’s marketing more than anything else. It’s up to students to decide. I GUARANTEE you, if you regularly go to instructor office hours and engage in meaningful discussion (not simply to beg a few points of a quiz), you’ll serve yourself well, not only in college, but for the rest of your life.

Good luck

I disagree. Small classes do provide the chance to engage even for shy students who DON’T go to office hours.

My kid’s prof took each kid in his class (of 15), on a hike to get to know them, in groups of 3 or 4. ALL of them. Before that, she’d run into him walking to the dining hall and they chatted - he recognized her from class.

It just doesn’t happen in large classes - that’s when it is truly important to go to office hours and develop a relationship but as you say, not every student can or will do this.

Agreed – you can lead a horse to water and whatnot. I’ve had students in my discussion sections and summer classes (~15-20 students) stubbornly refuse to talk in class despite my best efforts to engage. Some kids are just a lot more comfortable sitting in the back and absorbing things.

The same point can be made about virtually all college resources.
They don’t benefit every student equally.