Scientific Questionnaire

The Effect of Grade Level on Hours of Sleep


Do the Sophomores of last year get less sleep on school nights on average than that of the Freshmen of last year?


Sophomores will have less sleep on a school night than freshmen during the school year of 2014-15.

Type of Investigation

It is a comparative investigation due to the lack of a control group.

Parts of the Investigation

Independent Variable: Grade of the Student

Dependent Variable: Hours of sleep on school nights last year

Control Group: None

Experimental Group: All groups (9th and 10th graders)

Constants: School people came from, similar amounts of AP classes in each respective group

The Manipulated Data of the Amount for Sleep in Hours on a School Day for 9th/10th Graders Last Year

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When surveying a group of 13 ninth graders and 13 tenth graders, it was shown that there was no significant difference between the two groups in the number of hours slept on a school night last year.

The average for the 10th grade group were around 6.538 hours while the 9th grade group had a higher average sleep time, sitting around 7.15 hours. However, the P value was calculated as 0.155 which indicates that the two groups are not statistically significant, or that the independent variable has no effect on the dependent variable. The 2SEM graph also displays this, the 2SEM bars, whose values are 0.983092 for 9th graders and 0.664692 for the 10th graders, end up overlapping one another. This additionally displays that there is no significant difference between groups; the grade change from 9th to 10th did not correlate to the amount of sleep received each school night.

The factors that were hypothesized to have affected the amount of sleep were the increasing number of AP classes, amount of homework, and possibly extracurricular activities, leading to a greater workload. Inherently, the increasing workload also leads to less and less sleep. Studies have shown that nearly 20 percent more 12th-grade students have sleep deficits than do those in ninth grade, showing that workload does indeed have and effect on the hours of sleep. (1) Another study conducted by the National Sleep Foundation, concluded that in 9th grade, the average adolescent sleeps for 7.6 hr per night, and this time decreases to 7.3 hr in 10th grade (2). This study shows the same trend as Duval's, albeit on a smaller scale. The change occurs due to the aforementioned slight increase in workload, but is also offset by upperclassmen having more experience in tackling workload. Although there is a trend of less sleep as students pass their years through high school, the change between freshmen and sophomores is not as apparent as between other years. Conclusively, the hours of sleep sophomores get is not significantly lower than the hours of sleep freshmen get on an average school night throughout the school year.


The hypothesis that sophomores will have less sleep on a school night than freshmen during the school year of 2014-15 was not supported by the data. When surveying a group of 13 freshmen and sophomores of the past school year, it was shown that there was no significant difference between the two groups in the number of hours slept on a school night last year.

Sources of Inaccuracy/Errors

One source of inaccuracy that affected our experiment was how hard each individual decided to work on their homework. This would cause some slight differences in how long the work took them, slightly changing the amount of sleep they get. Another inherent accuracy would be the extracurricular activities and study habits of each individual. One who had more activities outside of school would have to start their work later in the day, reducing the amount of sleep. Likewise, the study habits of each individual would play a huge role in how much they sleep. Someone who does all of their work without delay nor distraction would be able to go to bed faster than someone who puts off their work till the night. These inconsistencies are something that would be accounted for in a revision of this experiment.


1) Duval, Sylviane. "Most High School Students Are Sleep Deprived." Most High School Students Are Sleep Deprived. N.p., 5 Jan. 2010. Web. 07 Sept. 2015.

2) Gillen-O’Neel, Cari, Virginia Huynh, and Andrew Fuligni. Child Development, Xxxxx 2012, Volume 00, Number 0, Pages 1–10 To Study or to Sleep? The Academic Costs of Extra Studying at the Expense of Sleep (n.d.): n. pag. Https:// National Sleep Foundation. Web. 6 Sept. 2015

3) Martin, Jennifer. "Designing a Scientific Questionnaire". 4 Sept. 2015