PSY 335 Week 1 The Scientific Method and Reading Research Example

Screens at Bedtime: Using the Scientific Method to Read and Critique a Sleep Study

[Student Name]

University of Phoenix

PSY/335: Research Methods

Week 1 Assignment

[Instructor Name]

[Date]

The student researcher and her question are composites written for a model paper; research findings come from the sources listed.

Most people hold beliefs about behavior drawn from experience: that phones keep us awake, that cramming works or that opposites attract. The scientific method puts such beliefs up against evidence that anyone can check. This paper applies the method to one student's question about bedtime screen use and critiques a published study that addresses it.

A Question From Everyday Life

Marisol is a twenty-year-old psychology major at a university in Phoenix, Arizona. Most nights she scrolls social media or watches short videos in bed for an hour or more, then struggles to fall asleep and drags through her eight o'clock statistics class. Friends tell her the blue light from screens is the problem; her roommate says it is the content, not the light. Marisol wants to know which, if either, is true.

Other Ways of Knowing

Before turning to research, it is worth noting how Marisol currently knows what she knows. Her friends' claim rests on authority and repetition: they have heard it often. Her own sense that screens keep her up rests on intuition and personal experience, which can mislead because she notices bad nights after scrolling and forgets bad nights without it. Science differs by testing claims systematically, with procedures that others can check and repeat.

The Steps of the Method

The scientific method moves from observation to question, from question to hypothesis, from hypothesis to a test, and from results back to theory. Marisol's observation is that she sleeps poorly after scrolling. Her question is whether screen use before bed delays sleep. A testable hypothesis must be precise and falsifiable: college students who use a phone for an hour before lights out will take longer to fall asleep than when they read a printed book for the same time. Some possible result, no difference in time to fall asleep, could show it wrong.

The hypothesis also needs operational definitions. Screen use might mean minutes of phone use logged by an app; time to fall asleep might be measured by a wrist-worn activity tracker or a sleep diary. Each choice affects what the study can show.

Finding a Study

A search of PsycINFO for "screen" or "light-emitting," "bedtime" and "sleep latency," limited to peer-reviewed empirical articles, located a controlled laboratory study that closely matches Marisol's question.

Summary of the Study

Chang et al. (2015) brought twelve healthy young adults into a sleep laboratory for two weeks. On five consecutive evenings, participants read for four hours before bed on a light-emitting tablet; on five other evenings, they read a printed book under dim light. Each person experienced both conditions, in counterbalanced order. Compared with the printed book, reading on the tablet lengthened the time it took to fall asleep, suppressed the evening rise of melatonin, delayed the timing of the body clock, reduced rapid eye movement sleep and left participants less alert the next morning.

Strengths

The design has several strengths. Because each participant served in both conditions, differences between people, such as natural night-owl tendencies, cannot explain the results. Counterbalancing the order prevents the first week's experience from biasing the second. Sleep and melatonin were measured objectively in a controlled environment rather than by self-report, and room light, meals and bedtimes were held constant, which strengthens the case that the screen itself caused the changes.

Limitations

The same control limits how far the findings travel. Twelve participants is a small sample, so estimates of effect size are imprecise. Four hours of reading is far longer than most students spend on a phone before bed, and a tablet held at reading distance may differ from a phone. The lab removed the content Marisol's roommate suspects, the social media posts and videos that may excite or upset, so the study tests light rather than engagement. Participants were healthy young adults without sleep disorders, and results may differ for people already sleep-deprived.

The study answers the friends' theory about light; it leaves the roommate's theory about content untested.

One Study Is Not the Last Word

Open Science Collaboration (2015) repeated 100 studies published in leading psychology journals and found that far fewer of the repeated studies produced significant results than the originals had, and effects in the repetitions were on average about half as large. Simmons et al. (2011) showed that common, often unreported choices during analysis, such as deciding when to stop collecting data or which measures to report, can make false positive findings far more likely than the stated alpha suggests.

These findings do not mean the screen study is wrong. Its design, with objective measures and a fixed protocol, guards against many of these problems. They do mean that Marisol should treat it as strong but incomplete evidence and look for replications, ideally with larger samples and realistic phone use.

Refining Marisol's Question

Reading the study sharpens Marisol's question. She now sees two separate possibilities, light and content, and realizes a study could separate them, for example by comparing phone use with a night filter against phone use without one, and calm content against social media. She also sees that a realistic study would use shorter exposure, students' own phones and their own bedrooms, trading some control for relevance.

Reading the Parts of an Article

The critique also shows why each section of an APA research report matters. The abstract gave the headline result. The introduction explained why evening light might matter for the body clock. The method section revealed the small sample and the long reading period, details absent from news coverage. The results section reported the size of each effect, and the discussion acknowledged that a lab differs from a bedroom.

Conclusion

The scientific method turned Marisol's hunch into a falsifiable hypothesis with measurable variables. A well-controlled laboratory study supports the idea that evening screen light delays sleep and lowers morning alertness, though its small sample, long exposure and lab setting limit generalization. Research on replication and analytic flexibility explains why her next step should be further testing rather than certainty.

References

Chang, A.-M., Aeschbach, D., Duffy, J. F., & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences, 112(4), 1232-1237. https://doi.org/10.1073/pnas.1418490112

Open Science Collaboration. (2015). Estimating the reproducibility of psychological science. Science, 349(6251), Article aac4716. https://doi.org/10.1126/science.aac4716

Simmons, J. P., Nelson, L. D., & Simonsohn, U. (2011). False-positive psychology: Undisclosed flexibility in data collection and analysis allows presenting anything as significant. Psychological Science, 22(11), 1359-1366. https://doi.org/10.1177/0956797611417632