Clock vs. Air Purifiers: Class Time Matters More Than You Think! 🕒📝

You know that feeling when you're sitting in an 8:30 am lecture, struggling to keep your eyes open? Or when you're fighting off a food coma in a 1:30 pm class right after lunch? Well, turns out you're not alone - and it might be affecting you much more & longer. In a large-scale anonymous survey on student satisfaction and performance, we found that class timing can be a big factor relating to students’ satisfaction and probably learning outcomes.

In a series of ongoing projects exploring the effect of indoor environments on human cognitive performances (i.e. learning outcomes, work productivity, emotion, etc.), researchers of MCRE utilize all kinds of methods (sensors, surveys, etc.) to unveil this connection. In this study, moving beyond traditional survey methods, we employed the BERT model to analyze a wealth of open-ended question responses, extracting contextual sentiment. This approach allowed us to quantitatively “read between the lines” and delve deeper into the nuanced opinions and feelings of participants.

Among all the factors that affect the students’ responses, we are surprised by the effect of an unexpected one: class time. Turns out, the time of day a class is held is a WAY bigger deal than any of the indoor air quality features, including CO2, particles, temperature, etc. Students absolutely dislike those 8:30 am and 1:30 pm classes compared to other time slots. The winner is the 4:00 pm classes with the highest rating and more positive sentiment in the course survey: a massive 0.41 point advantage over the 8:30 am slots. In comparison, most of the indoor environmental factors the researchers measured barely moved the needle. (The only exception was particulate matter (PM), which had a small 0.24 point impact).


Interestingly, some other studies also find similar “early morning effects”, although the mechanism behind it is still under discussion. In a paper published in Nature Human Behavior, researchers also found the negative impact of early morning classes --associated with lower attendance, shorter sleep, and poorer academic achievement-- by analyzing university students’ digital traces. One easy-to-guess reason is that with the popularity of mobile devices and all sorts of online activities, we're falling asleep later and later, thus making the early morning effects much more significant than before.

Although observing a correlation is just the starting point, it's an exciting reminder that there's so much more to discover about the nuance of human behavior: some details, like an early waking-up or a food coma after a good lunch (NOTE: strictly speaking we are NOT sure if they really cause the difference), may just secretly shape our experiences and opinions. This has important implications. Can we rethink our schedules and put the most important tasks or challenging courses in those “late afternoon sweet spots” to boost productivity?