The Effect of Grade Level on Sleep

By: Sravika K. and Taniya K.


Does grade level affect the amount of sleep a student gets?


11th and 12th graders will get less sleep than 9th and 10th graders.

Type of Investigation

This type of investigation would be comparative, where 9th and 10th graders are being compared to 11th and 12th graders in the aspect of how much sleep they get.

Parts of the Experiment

Independent variable: Grade level

Dependent variable: The amount of sleep student gets

Control group: None

Experimental group: 28 students (7 from each grade level)

Data Table

Big image

Bar Graphs


11th and 12th graders attained less sleep than 9th and 10th graders. When looking at the mean of the two groups, 9th and 10th graders had an average of 7.5 hours, while 11th and 12th graders had 6.5 hours, showing the decreasing amount of hours as grade levels change. As per Standard Deviation and Standard Error of Measurement, the error bars do not overlap enough, displaying that the difference was indeed not significant enough. The p-value for the data collected was 0.009, which also shows the significance of data, considering that it is under 0.05. As high school life progresses, students tend to take more harder classes, such as AP, and at the same time, there are other pressures such as SATs, ACTs, and college admissions. Such things are not commonly dealt with as a freshmen or a sophomore, but juniors and seniors go through long hours of working on them as they get closer to graduating. This leads to students in higher grades to receive less sleep, as stated by a study done by the National Sleep Foundation.


The hypothesis was supported with evidence stating that grade level does indeed affect the amount of sleep, considering that 11th and 12th graders obtained less sleep than 9th and 10th graders.

Sources of Inaccuracies/Error

Hours spent on after school activities takes away time to do homework, which in turn takes away hours of sleep. Some people spend hours on after school activities, while others may not. This would definitely skew the data and be one of the major sources of error. In addition, some students may take longer to do homework that someone else would do in a short amount of time relatively, considering everyone has a different intellectual level, along with the difficulty of classes they take. In such situations, inaccuracies in results may occur.


"High School Students Getting Less Sleep." National Sleep Foundation. National Sleep Foundation, 25 Jan. 2010. Web. 04 Sept. 2014. <>.

Martin, Jennifer. Video on Biostats. 04 Sept. 2014

Martin, Jennifer. Video on T-test and Correlation. 04 Sept. 2014

Martin, Jennifer. Directions on CER. 04 Sept. 2014