| Course | HLTH 8745 Health Psychology |
|---|---|
| Week | Week 5 |
| Paper type | Measurement critique |
| Length | About 600 words, 5 pages |
| Format | APA 7 student paper |
| School | Walden University |
| Program | PhD in Public Health |
| Updated | October 2026 |
Free sample paper for HLTH 8745 Week 5
Measurement Critique: Why One Afternoon Saliva Sample Could Not Detect the Cortisol Difference a Teaching-Case Study of Stressed Teachers Called Absent
Student Name
Walden University
HLTH 8745: Health Psychology
Instructor Name
Month Day, Year
Measurement Critique: Why One Afternoon Saliva Sample Could Not Detect the Cortisol Difference a Teaching-Case Study of Stressed Teachers Called Absent
The Study and Its Conclusion
In a teaching case, a school district study gave 214 teachers the ten-item Perceived Stress Scale and collected one saliva sample from each during a weekday afternoon, anywhere from two to four o'clock. Teachers in the top third of perceived stress had mean cortisol levels no different from those in the bottom third. The authors concluded that felt stress "leaves no biological signature" in this group. The critique examines how both variables were measured and argues that the cortisol measure was poorly placed to detect the difference the authors called absent.
How Perceived Stress Was Measured
The Perceived Stress Scale asks how often in the past month respondents felt that life was unpredictable, uncontrollable and overloaded (Cohen et al., 1983). It measures appraisal over weeks, not a reaction at a given moment. That matters for the comparison: a teacher who has felt overloaded for a month would be expected to show changes in the pattern of cortisol across days, not necessarily a higher level at one afternoon hour.
How Cortisol Was Measured
Cortisol follows a strong daily rhythm. Levels rise sharply in the 30 to 45 minutes after waking, a rise called the cortisol awakening response, then decline through the day to low levels in the evening. Adam and Kumari (2009) reviewed salivary cortisol in large studies and stressed that single samples are highly sensitive to time of day, time since waking and other factors, and that the measures most often linked to chronic stress are features of the daily pattern, such as the awakening response and the slope of decline across the day.
Expert guidelines on the awakening response stress strict timing relative to waking and checks on whether participants sampled when instructed (Stalder et al., 2016). The study met none of these conditions.
Table 1
What the Study Measured Against What Chronic Stress Research Typically Requires
| Feature | Study | Typical requirement | |
|---|---|---|
| Samples per person | One | Several per day, often over two or more days | |
| Timing | Mid-afternoon, a two-hour window | Fixed to waking, plus samples across the day | |
| Waking time recorded | No | Yes, to compute awakening response | |
| Days sampled | One | Two or more to separate day-to-day variation | |
| Adherence to sampling times checked | No | Yes, by electronic monitoring or diary | |
Requirements summarize recommendations in Adam and Kumari (2009) and Stalder et al. (2016).
Why the Null Result Is Uninformative
An afternoon sample falls in a period when cortisol is relatively low and flat, so differences linked to chronic stress, such as a flattened daily slope or an altered awakening response, would barely register. The two-hour window adds noise, since cortisol continues to fall during that period. A teacher sampled at 2 p.m. and one at 4 p.m. differ for reasons unrelated to stress. With one sample per person, these sources of noise cannot be averaged out. Under these conditions, failing to find a difference says more about the measure than about teachers.
Acute stress responses, by contrast, are best captured with laboratory stressors that include social evaluation and uncontrollability, which Dickerson and Kemeny (2004) found produced the largest cortisol responses. The study measured neither the acute response nor the daily pattern.
Conclusion
The study cannot conclude that felt stress leaves no biological signature. It can conclude only that one afternoon sample did not differ by perceived stress. A redesign would collect samples at waking, 30 minutes later, and at set times across two weekdays, with waking times recorded.
References
Adam, E. K., & Kumari, M. (2009). Assessing salivary cortisol in large-scale, epidemiological research. Psychoneuroendocrinology, 34(10), 1423-1436. https://doi.org/10.1016/j.psyneuen.2009.06.011
Cohen, S., Kamarck, T., & Mermelstein, R. (1983). A global measure of perceived stress. Journal of Health and Social Behavior, 24(4), 385-396. https://doi.org/10.2307/2136404
Dickerson, S. S., & Kemeny, M. E. (2004). Acute stressors and cortisol responses: A theoretical integration and synthesis of laboratory research. Psychological Bulletin, 130(3), 355-391. https://doi.org/10.1037/0033-2909.130.3.355
Stalder, T., Kirschbaum, C., Kudielka, B. M., Adam, E. K., Pruessner, J. C., Wüst, S., Dockray, S., Smyth, N., Evans, P., Hellhammer, D. H., Miller, R., Wetherell, M. A., Lupien, S. J., & Clow, A. (2016). Assessment of the cortisol awakening response: Expert consensus guidelines. Psychoneuroendocrinology, 63, 414-432. https://doi.org/10.1016/j.psyneuen.2015.10.010
The Walden HLTH 8745 Week 5 instructions
Students critique how a study measured its key variables and whether those measures support its conclusion. Faculty expect the critique to describe each measure accurately, explain what it captures and over what time frame, and compare the study's procedures with established methodological guidance. The strongest critiques show specifically why a measure could fail to detect a difference, rather than simply calling it weak. A table comparing the study's methods with recommended practice is a useful format. Faculty value critiques that distinguish between a finding that a difference is absent and a finding that the study could not detect one. Recommendations should describe a better design in concrete terms, including timing, number of samples and checks on participant adherence.
How this HLTH 8745 Week 5 example is built
The critique opens with the teaching-case study's design and its conclusion. A section describes the Perceived Stress Scale, citing Cohen and colleagues, and notes its month-long time frame. A section describes cortisol's daily rhythm and cites Adam and Kumari on the sensitivity of single samples and the measures linked to chronic stress. Table 1 compares the study's sampling with typical requirements, citing Stalder and colleagues on the awakening response. A section explains why an afternoon sample with a two-hour window is uninformative and cites Dickerson and Kemeny on conditions that produce acute cortisol responses. The conclusion restates what the study can claim and proposes a redesign with timed samples across two weekdays.
Where the marks sit in the HLTH 8745 Week 5 rubric
Faculty grade the critique on accurate description of the measures and on the logic connecting measurement to the conclusion. Calling the cortisol measure inadequate without explanation earns little. Credit rises when the critique explains the daily rhythm, the time frame of each measure and how the sampling window introduces noise. Comparing the study's methods with published guidelines in a table earns credit for precision. Graders look for the difference between a study that found nothing and a study that could not have found anything. A redesign earns credit when it specifies timing, number of samples and adherence checks. Accurate citation of methodological sources is expected. Avoiding overstatement, such as claiming the study proves stress does affect cortisol, shows balanced judgment.
HLTH 8745 Week 5 help: mistakes that cost marks
Measurement critiques often list weaknesses without showing how they affect the result. To write a stronger critique, describe what each measure captures and over what period. Look up methodological guidance for the biological measure and compare the study's procedure with it, item by item. Explain how the gaps could hide a real difference, for example by sampling at a time when differences are small or by adding noise. Distinguish what the study found from what it could have found. Propose a better design in concrete terms. A measurement critique of the study your section assigns can be written from these steps.
Get a HLTH 8745 Week 5 example written to your instructions
Provide the assigned study or its reference, with the critique prompt and rubric. The paper that returns judges each instrument by what it can detect, explains any mismatch between a measure's timing and the question asked, and restates null findings at their true strength. Its school district is not real. Delivery is 24 to 48 hours; the first is free.
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HLTH 8745 Week 5 questions, answered
Is self-report weaker evidence than a biomarker?
Not automatically, because they measure different things. A perceived stress score is the right measure of appraisal, and no biomarker substitutes for it; cortisol is informative about one physiological system and says nothing direct about how a person experiences their situation. The sample criticizes the study for how it sampled cortisol, not for asking people how stressed they felt.
Why does the time of the saliva sample matter so much?
Because cortisol follows a daily pattern, rising after waking and declining through the day, and stress research often examines that pattern rather than a single level. An afternoon sample falls on a flatter stretch of the curve where differences are harder to see. Your critique does not need exact values to make this point; describing the rhythm accurately is enough.
Can a critique conclude that the study was worthless?
It can, but the sample does not, because that would overstate the case. The stress scale data remain usable, and the study documents a question worth asking. The critique restates the cortisol result as inconclusive and explains what design would be needed. Proportionate conclusions usually score better than dismissals, which read as a reaction rather than an appraisal.
Where can I find a free HLTH 8745 Week 5 sample paper?
This page holds the complete Week 5 measurement critique, showing why one afternoon saliva sample could not detect a cortisol difference between teachers with high and low perceived stress, with four references.
Why does one afternoon cortisol sample miss chronic stress effects?
Cortisol rises after waking and falls through the day, and the features most linked to chronic stress are the awakening response and the daily slope. A single afternoon sample falls in a low, falling period and varies with time of day, so differences can be hidden.