Because CS10, being an intro class, has its highest enrollment in Fall, not in Spring.
In the most recent CS10 cohort (the one in which 35% of grades were an F) only 34 students were graded.
If you're going to look at intro classes, why not look at the Fall semesters, which have much higher enrollment?
# grades % F grades
Fall 2019 268 0.37%
Fall 2020 259 8.49%
Fall 2021 342 3.22%
Fall 2022 218 13.30%
Fall 2023 194 7.22%
Fall 2024 169 1.18%
Fall 2025 146 2.74%
Additionally, if someone is taking an intro class in the Spring, that's probably because they already failed it in the previous semester. While that doesn't guarantee that they'll fail again, it does make it more likely.
Sure, but 12 people got an F in CS10 in Spring 2026, which is higher than any prior spring. The second-highest number of Spring F grades was 9, in Spring 2022, when four times as many students were graded (133 vs 34).
Separately, there's a clear downward trend in the number of grades being awarded in the fall semester. Perhaps students have the option to take the course pass/fail?
12 Fs across 34 students is not statistically significant. Comparing the spring 2022 vs spring 2026 rates only works if the composition of the groups is similar (e.g. same % of students that previously failed the course), which seems dubious given the dramatically different sample sizes.
That doesn't mean there isn't a problem worth investigating. If I was a dean I'd certainly have some questions if I found out that 35% of students failed a class. But without knowing the specifics it's irresponsible to draw any conclusions about these 34 students with the limited data we have available.