Research on general cycles of student alertness and fatigue at different ages
Student sleepiness at school is a wide spread phenomenon according to teachers' reports in
international assessments – on average internationally, this limited the effectiveness of instruction for
around half of Grade 4 students (e.g. Mullis et al., 2012b, Exhibit 8.10) and for nearly 6 out of 10 Grade 8
students (e.g. Martin et al., 2012, Exhibit 8.22). Research from different countries has identified the
phenomenon that students experience different cycles of alertness and fatigue during the typical school day
and week. This has been well documented for over a century and fits in with broader research on different
cycles of alertness for human beings (Davila and Devolvé, 1994). Although there are individual differences
that are reflected in learning time preferences (see Box 4.2),


 the observed fluctuations in human alertness
also vary by age, which suggests that the amount of instruction time should be adapted accordingly.
Cycles of alertness at different ages
Testu (2008) and Dubocovich et al. (2005) believe that research from different countries has identified
some universal patterns. Baade (1907) observed two cycles of alertness among primary school children
with their attention increasing until around a.m., falling until 2 p.m. and recommencing. Later research
(Rutenfranz and Hellbrügge, 1957; Fischer and Ulich, 1961) found that school age participants performed
best on mathematics calculations between 10 a.m. and midday and between 3 p.m. and 4 p.m., while they
performed worst during the first hour of the school day and around 2 p.m. More recent research also
identified similar daily cycles of students’ alertness in the United Kingdom, Germany, Spain, Israel and the
United States (Andrade and Menna-Barreto, 1996; Klein, 2004). 


Testu (1994a, 1994b, 2008) finds that
children aged 10 to 11 have an initial low level of alertness around 8 a.m. to 9 a.m. and that this rises to a
peek of alertness around the end of morning classes (11 a.m. to 12 p.m.) (Figure 2.3). There is a second
low in level of alertness immediately after lunch break, but alertness increases to an afternoon peak around
4 p.m.
Importantly, the observed cycles of alertness change significantly as children grow up. Both the
length and amplitude of cycles of alertness change with age. For example, students aged 13 to 14 have
their attention peaks later than those aged 9 to 10 (Fischer and Ulich, 1961). Also, the youngest children
(aged 5 to 9) tend to have a much weaker or even negligible peak of alertness in the afternoon and,
consequently, show much weaker afternoon performance than older students. In research between 1972
and 1978 on teaching behaviours that are conducive to learning, Fisher (1978) found higher estimates of
actual learning time for children in higher grades, reflecting that older children could concentrate for
longer periods of time (11 minutes of mathematics and 19 minutes of reading in Grade 2; 15 minutes and
35 minutes respectively in Grade 5).
EDU/WKP(2016)1
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Accordingly, some researchers advocate for different amounts of instruction time for children of
different ages.


 Touitou and Bégué (2010) believe that a system which would respect biological rhythms
should encompass, depending on the age, 4 to 6 hours of instruction time a day, 4 days and a half up to
5 school days a week and 180 to 200 school days a year. In turn, La ligue de l’enseignement (2010)
advocates a daily instruction time of five hours for primary school children due to their more limited
attention span. Suchaut (2009) argues that time organisation should take into account research evidence
and limit the school week to around 20 hours until the 3rd Grade and introduce a shorter daily instruction
time distributed across a larger number of days. This should be no more than six hours of instruction per
day in lower secondary school and no more than seven hours in upper secondary school. Testu (2008)
suggests that increases in the weekly number of hours should occur as a function of a student’s age, with
21 hours for children aged 6 to 9, 25.5 hours for children aged 9 to 13, 28 hours for students aged 13 to 15
and 31 hours for those aged 16 to 19. For all age groups, Testu advocates classes beginning no earlier than
8.30 a.m. and a long midday break (12 to 2.30 p.m.) that would help in managing the midday fall in levels
of student alertness.