Since the decision to concentrate all teaching-learning sessions in the first half of the day (before lunch) in the Canary Islands at the beginning of the 1990s , the so-called continuous school day has been extended to the vast majority of communities. Spanish autonomous. The split school day, with learning sessions before and after a lunch break, dwindles each year.

Some of the arguments used by the defenders of the first is that it reduces student fatigue and favors attention and academic performance. Now, what does the research say about the impact of the continuous and split school day on students?

Studies and limitations

To begin with, it should be emphasized that the studies that have been carried out to date to determine which type of day favors academic performance to a greater extent are scarce and present a series of methodological limitations that make it difficult to obtain a conclusive answer.

For example, it is not always possible to isolate the effect of the type of day from that of other variables , such as the type of school or the characteristics of the student body. With this in mind, the results available in Spain do not point to a superiority of the continuous school day over the split school day and rather suggest that the split shift promotes academic performance to a greater extent.

Attentional cycles

In contrast to the above, there are abundant studies on how the attentional cycles of schoolchildren are distributed throughout the school day.

To answer this question, attention is measured at different times of the day with, for example, visual discrimination tasks, in which students have to locate specific letters, numbers or symbols within a string in a limited time.

By stages, the results show that:

1. In kindergarten students there is an increase in attention in the morning that decreases in the afternoon.
2. In primary school students , the peak of greatest attention begins to move to the afternoon.
3. And in students in the upper stages of primary school, the highest levels of attention shift clearly towards the afternoon, while they remain especially low during the first hours of the morning.

In general terms, it could be said that students experience an attentional peak until midmorning and another more or less pronounced throughout the afternoon. Precisely for this reason, the split school day, which is divided into two school periods (one in the morning and the other in the afternoon), is better adapted to the attention curve of schoolchildren than the continuous day.

Adolescents: a special case

The case of adolescents deserves special consideration. On the one hand, it should be emphasized that in the secondary stage of the Spanish educational system the continuous school day predominates.

Added to this is the fact that the average number of class hours that adolescents spend in the classroom in Spain is significantly higher than the OECD average, an issue that is not reflected in external assessment tests, such as PISA.

The result is that adolescents start the day very early in the morning to cover all the stipulated daily learning sessions.

Change in sleep patterns

However, there is strong evidence that this population is characterized by different sleep patterns than the preadolescent or adult population. Specifically, young people of these ages are more active and alert as night approaches; they are inclined to delay going to bed and experience, as a consequence, a clear sleepiness in the early hours of the morning.

What is the result of this disconnect between school hours and adolescent sleep cycles? That they receive a good part of the classes in a clear state of torpor; by the way, often confused with a climate of concentration heightened by the silence that prevails in the classroom in the early hours of the morning.

In fact, numerous studies have highlighted how starting the school day first thing in the morning translates, for practical purposes, into sleep deprivation at these ages. And this has undesirable consequences , such as the appearance of behavioral problems, inattention, lower academic performance or a greater number of accidents or injuries.

Start later

A solution raised on numerous occasions by the scientific community is to modify the start time of the school day.

Decision-making in educational matters is complex and always involves multiple factors. Although more research is still needed in this field, it would be highly recommendable to take into account the available evidence on the distribution of learning sessions throughout the day and its relationship with the academic performance and well-being of schoolchildren.

Author Bio: Martha Ferrero Gonzalez is Professor, researcher and vice dean of research and transfer at the Faculty of Teacher Training and Education at Autonomous University of Madrid