Night-time phone use and sleep among Form 4 day scholars at a secondary school in Gaborone

A. Introduction

Aim and research question

This proposal aims to investigate the relationship between night-time phone use and hours of sleep on school nights among Form 4 day scholars at a day-and-boarding secondary school in Gaborone, Botswana. The research question is: What is the relationship between the time Form 4 day scholars last use their phone at night and how long they sleep on school nights? Because a survey cannot manipulate phone use, the proposal looks for a relationship, not a cause.

The problem and its effect on the population

Day scholars are the right group to study because, unlike boarders at the same school, they have no lights-out rule and usually keep their phone in their bedroom. The American Academy of Sleep Medicine recommends that teenagers aged 13 to 18 sleep 8 to 10 hours in every 24 hours (Paruthi et al., 2016), yet many day scholars leave home before 06:30 to catch transport, so a late night cannot be made up with a later morning. This is a problem because sleep supports attention, memory and mood, and Form 4 is the year in which students cover much of the content for the BGCSE examinations at the end of Form 5. A shortfall that repeats every school night adds up across a term.

The effect on this population is visible in school. Several Form 4 teachers have told me that their day scholars often look tired in first lessons, and some students admit to falling asleep in class. Tiredness of this kind can lower concentration and marks in the year before national examinations, and irritability can strain relationships with teachers and family.

Relevant research

[S1] Hysing et al. (2015) surveyed 9,846 adolescents aged 16 to 19 in Hordaland, Norway, about the electronic devices they used in the bedroom in the hour before sleep, and about their sleep. Most adolescents used at least one device in that hour, and using a mobile phone at bedtime was associated with taking more than 60 minutes to fall asleep and with sleep deficiency. The researchers concluded that technology use is negatively related to sleep and that advice on healthy media use could include restricting devices at bedtime; because the study was cross-sectional, they could not conclude that phones cause poor sleep. This helps address the problem because it suggests that the timing of phone use, not only its total amount, may matter for Form 4 day scholars, so my questionnaire asks when the phone is last used. It also shows that a self-report questionnaire can measure both variables in a school-age sample.

[S2] Perrault et al. (2019) followed adolescents aged 12 to 19 in Geneva, Switzerland, for one month using wrist actigraphy and daily questionnaires. After a two-week baseline and a 40-minute sleep-education workshop, students were asked to stop using screen devices after 21:00 on school nights for two weeks. Those who reduced their evening screen use fell asleep earlier and slept longer, and the longer sleep was associated with better daytime vigilance. The researchers concluded that restricting evening screen use is a promising way to increase adolescents' sleep. This helps address the problem because it suggests that a simple, school-promoted phone curfew could give Form 4 day scholars more sleep and better attention in first lessons.

How the research shapes this proposal

Together, these studies suggest that late phone use and shorter sleep go together, and that cutting phone use after a set time can help. Neither study was carried out in southern Africa, where transport times, housing and phone habits may differ, so it is worth finding out whether the same pattern holds for day scholars in Gaborone before the school recommends any change.

B. Research methodology

Research method

This study will use a survey: an anonymous questionnaire combined with a seven-night sleep diary. An experiment would mean controlling students' phone use at home, which is neither practical nor ethical for a student researcher, and S2 has already tested a curfew. Interviews would give depth but from too few students to see a pattern across Form 4. Observation is impossible because phone use happens at night in private homes. A survey can reach a large enough sample to look for a relationship, and S1 shows that both variables can be measured by self-report.

Procedure

Stratified random sampling will be used. The school has four Form 4 classes, and each class list of day scholars will be numbered and 15 students drawn by a random-number generator, giving 60 participants, mostly aged 15 to 17. Stratifying by class ensures each timetable and set of teachers is represented, and prevents over-representing the Form 4 class I help with as a peer tutor, where friends might answer to please me. Boarders are excluded because their lights-out rule would hide the relationship I am interested in. A sample of 60 was chosen because it is large enough to see a pattern and small enough for me to manage.

The design is correlational: each student provides an average "last phone use" time and an average sleep duration across the five school nights in the diary, and the two will be compared. Because diary times are estimates and late outliers are likely, the relationship would be tested with Spearman's rank correlation, which compares ranks rather than exact values. The setting is the school library during a free period, because it is quiet and away from teachers who might see answers. On a Friday, I will explain the study, collect signed forms and give each participant an envelope with the questionnaire, a diary and a code number. Students complete the questionnaire on the spot (about ten minutes), then fill in the diary each morning for the following seven nights, Sunday to Saturday, so that five school nights and two weekend nights are covered. On the Monday after the last entry, the diaries are returned in the sealed envelope to a box in the library.

Ethical considerations

The IB requires written parental consent for participants under 16 (International Baccalaureate Organization, 2025); my school requires it for everyone under 18, so an information letter and consent form will go to the parents of every participant, and each student will also sign their own assent form. This matches APA Standard 3.10 (American Psychological Association, 2017), which asks for the young person's assent as well as permission from a “legally authorized person”, and the school will give written permission because the study takes place on its premises. Students will be told in writing and in person that they can withdraw at any time, and can withdraw their data until the diaries are returned, by quoting their code. Questionnaires carry a code, not a name, and the code list is kept separately in a locked drawer, so no teacher or parent can link answers to a student who admits to using a phone at 01:00 against family rules. To protect participants from harm, no item asks about the content of phone use, and a student who reports very little sleep will receive, with everyone else, a debrief sheet with sleep-hygiene advice and the school counsellor's contact. There is no deception, and the full aim is shared in advance.

C. Data collection

The data-collection tool

The tool, given in full in the appendix, has two parts: a ten-item questionnaire completed once, and a seven-night sleep diary with four entries per night. For example, item 3 asks: On a typical school night, at what time do you last use your phone? with the options before 20:00, 20:00–21:59, 22:00–23:59, midnight or later, and I do not have a phone. The diary asks each morning for the time the student got into bed, the time they last used their phone, the time they think they fell asleep and the time they woke up. Sleep duration is then calculated from the estimated time of falling asleep to waking. Together, these items measure both variables in the aim: when phone use stops, and how long the student sleeps on school nights.

Design decisions

Time bands were used in item 3 instead of an open answer because students may not remember exact minutes, and bands make answers easy to compare across 60 people. The diary, by contrast, asks for clock times, because it is filled in the next morning when memory is fresh, and exact times allow sleep duration to be calculated. A seven-night diary was added because one night may not be typical; a test the next day or a family event could change one night completely. The diary includes the two weekend nights even though the aim concerns school nights, because comparing the two shows whether early transport, rather than phone use alone, limits sleep. Items ask about behaviour (times, frequency) rather than opinions such as "Is your phone use a problem?", because opinions about phones are likely to be influenced by what adults say. The order moves from neutral items (transport, bedtime) to phone items and then to sleep and tiredness, so the form feels like a survey about school nights rather than a test of phone habits; the main sleep measure, the diary, is completed separately at home each morning, so sleep times are not written down straight after the phone items. The questionnaire is kept to ten items so that it fits in ten minutes of a free period and students do not rush the later items.

Likely challenges

One likely challenge is under-reporting. Students may give earlier times because they fear that parents will see the answers, especially where families have a no-phones-at-night rule, even though the forms are anonymous. The sealed envelopes and the return box are intended to reduce this fear. A second challenge is missing diary entries: day scholars leave home early, and a student who oversleeps may skip that morning's entry and try to remember it days later, which makes those times less accurate. Finally, some participants might not take the study seriously and give careless answers.

Estimating the time of falling asleep is also difficult, because nobody notices the moment they fall asleep. S2 used actigraphy to avoid this problem, but the school cannot provide wrist devices for 60 students, so sleep duration in this study will be an estimate, and this will be stated when the results are reported.

D. Discussion

Possible findings and implications

If day scholars who last use their phone after 22:00 report clearly less sleep on school nights than those who stop earlier, this would support S1 and S2 in a Gaborone setting. The school could then add a sleep-education session to Form 4 life-skills lessons, similar to the workshop used in S2, and suggest in the parent newsletter that phones are charged outside bedrooms on school nights. If the relationship is stronger on school nights than at weekends, this would suggest that early transport is what turns late phone use into lost sleep, which would also support discussing first-lesson times with the school.

If there is little relationship, the school may need to look at other causes such as homework or transport.

Researcher bias

As a day scholar at this school who was in Form 4 two years ago, I already expect late phone use to reduce sleep, so confirmation bias could lead me to read an unclear diary time, such as "11ish", as later rather than earlier when calculating sleep duration, strengthening the relationship I expect. To reduce this, diary times will be converted using written rules decided in advance (for example, "11ish" becomes 23:00), and a classmate who does not know the aim will check a random 10 of the 60 diaries. Because I know many participants, I could also unintentionally show approval when classmates mention late phone use while I explain the study, which could encourage them to exaggerate. Reading the same written instructions to every group reduces this expectancy effect.

An additional research method

The questionnaire can show whether late phone use and short sleep go together, but not why students keep using their phones when they know they are tired. A follow-up semi-structured focus group with six to eight volunteers from the sample could explore this. Scott et al. (2019) used focus groups with 24 adolescents aged 11 to 17 and found that night-time social media use was driven by fear of missing out and by expectations to stay available and reply quickly to friends. If similar reasons appear in Gaborone, a curfew aimed at individuals may not work, because the pressure comes from the whole friendship group; a class-wide agreement to go offline at the same time might be more effective. A focus group also suits the topic ethically: the IB guide lists media consumption and healthy lifestyle habits as suitable interview topics, while mental health concerns are not appropriate for students to explore with peers (International Baccalaureate Organization, 2025), so the questions would stay on habits and friendships rather than feelings. This would deepen understanding of the population's problem by explaining the behaviour that the survey can only measure.

Appendix: Data-collection tool (not included in the word count)

Part 1. Questionnaire (completed once, in the library)

Code number: ______   Do not write your name anywhere on this form. Tick one box for each question. There are no right or wrong answers.

1. How do you usually travel to school? ☐ Walk ☐ Combi or bus ☐ Family car ☐ Other
2. On a typical school night, at what time do you get into bed? ☐ Before 21:00 ☐ 21:00–21:59 ☐ 22:00–22:59 ☐ 23:00 or later
3. On a typical school night, at what time do you last use your phone? ☐ Before 20:00 ☐ 20:00–21:59 ☐ 22:00–23:59 ☐ Midnight or later ☐ I do not have a phone
4. Where is your phone while you sleep on school nights? ☐ In my bed ☐ Next to my bed ☐ Elsewhere in my bedroom ☐ Outside my bedroom ☐ I do not have a phone
5. On how many school nights in a usual week do you use your phone after you get into bed? ☐ 0 ☐ 1–2 ☐ 3–4 ☐ 5
6. On a typical school night, is your phone on silent or switched off while you sleep? ☐ Switched off ☐ On silent ☐ Sound on
7. In a usual week, how many times are you woken by your phone during the night? ☐ Never ☐ 1–2 times ☐ 3–4 times ☐ 5 or more times
8. On a typical school night, how many hours do you sleep? ☐ Less than 6 ☐ 6 to less than 7 ☐ 7 to less than 8 ☐ 8 to less than 9 ☐ 9 or more
9. In a usual school week, how often do you feel sleepy during your first lesson? ☐ Never ☐ 1–2 days ☐ 3–4 days ☐ Every day
10. In a usual school week, how often do you arrive late because you overslept? ☐ Never ☐ 1–2 days ☐ 3–4 days ☐ Every day

Part 2. Sleep diary (fill in each morning, Sunday night to Saturday night)

Write clock times (for example 22:40). If you are not sure, write your best guess and put a question mark after it.

When you have finished, put this diary in the envelope, seal it and drop it in the box in the library. Thank you for taking part.