Timing May Not be Everything. But it Matters
Updated: Oct 4
A teacher friend recently asked me about the timing of instruction and the best times to teach certain subjects. He wrote:
I immediately thought of the oft-cited study in which researchers evaluated judicial rulings on parole, across four Israeli prisons, to better understand factors that influenced parole decisions. Gender of the prisoner, the prisoner’s ethnicity (Arab vs. Jewish), the severity of the crime, e.g., fraud vs. assault, or the amount, amount of time already served, were all possibilities they thought might influence decision-making.
The parole boards consist of a judge, a criminologist, and a social worker and they spend the entire day reviewing applications presented in random order. The judges spend around six minutes on each case, the time of the decision is recorded, they have two food breaks (a morning break and an afternoon break), and in 65% of cases, parole is denied. Thus denial of parole can be thought of as the ‘default decision’. Data on decision-making vs. time of day were plotted on a graph.
Given this information, we’d expect the graph to look like this:
Interestingly it looked like this:
It turned out that as the judges got closer and closer to their food breaks, they increasingly resorted to the default position of parole denial. We know that engaging in complex decision-making is difficult and these data suggest that as the judges got hungrier and more in need of a break, they were less able to devote the intellectual effort needed to go against the default position of denial. Thus they were more likely to revert to the default and deny parole. Indeed, as you can see in the graph, right before the break the percentage of time parole was granted had fallen to zero!
Back to my friend and his question. The results of the judge study and others suggest that time of day does play a role in learning as does taking breaks. In his 2018 book When, Daniel Pink explores the mismatch between what we know about the best time to do things and the way educational scheduling happens. As you might imagine, most educational scheduling tasks are administrative. Pink, however, suggests we should take a more careful look at our scheduling from a pedagogical perspective.
A 2016 research study examined students’ class schedules, grades, and state exam scores from almost 2 million students in the Los Angeles Unified School district and found some interesting effects of time of day of instruction. “If a student took a math class at the beginning of the day in the first or second period compared to the end of the day, the fifth or sixth period, they performed significantly better on their math GPA and their math test scores.” (Pope, 2016). Increases in GPA were similar for having English class in the morning, vs. the afternoon, but there was not an increase in English state test scores.
Another study, this time in Denmark, found that “for every hour later in the day, test scores decrease by 0.9% of a standard deviation. In addition, a 20- to 30-minute break improves average test scores.”
As with the parole board, a likely explanation for this pattern is that over the course of a day students’ mental resources are increasingly depleted, they experience increasing cognitive fatigue, and as a result, are more likely to underperform on a test.
This research speaks to the ordering of the school day and differential learning throughout the day, rather than the specific time that it should start.
This is important.
It is acknowledged that as children grow and develop, physiological changes can cause delays in going to sleep in the evening and make it more difficult to wake up early in the morning. Less commonly acknowledged is the role of cognitive fatigue and decreased student performance across the school day (regardless of when it starts).
It can be tempting (as with many things) to try and figure out the “best time” to be teaching and learning specific subjects or doing certain tasks. The time-of-day effect, however, varies based on the nature of the task. As Simon Folkard said in Stress and Fatigue in Human Performance, “Perhaps the main conclusion to be drawn from studies on the effects of time of day on performance is that the best time to perform a particular task depends on the nature of that task.”
Are there key takeaways from these findings for schools, teachers, and education policymakers?
I think so.
We focus a lot of time and energy on what we are teaching, how we are teaching, why we are teaching, who is teaching, but not as much on the most effective and efficient timing of learning and when students are likely to be most productive.
We know that learning is hard and takes considerable effort. Thus we must work to schedule our students’ days accordingly and consider the impact of cognitive fatigue as well as the need for frequent breaks.
There may be certain classes or tasks which schools deem more or less cognitively taxing (think PE vs. math or science) and figuring out the best time to schedule them matters. It turns out that timing, while not necessarily ‘everything’, does make a difference and some subjects will be better placed in (as my teacher friend put it) the ‘golden hours’.