Week 10 — Does the App Cause Better Sleep? Testing Causal Claims in a Newsletter Blurb

Assignment 9 of the term — read a survey's pattern as a correlation, check it for a hidden third factor and a backward arrow, catch a cause inferred from order alone, test a chain of predicted consequences link by link, and explain to someone new why a striking pattern does not show that an app works.

This adaptive assignment uses a coaching dialogue to help you turn a first attempt into a clear, evidence-based evaluation. You remain the author. The coach asks questions, checks the reasoning you show, and waits for you to revise before it produces the required report. In Week 7 you learned that a fallacy is a flaw in the reasoning rather than a false premise, and in Week 9 you learned to ask how a group was chosen; this week you learned to ask what else could explain a pattern between two things. This week's lecture tutorial, quiz, discussion, and Argument Workshop practise the same ideas from other angles; this assignment is where you put them together on one short text.

The task

Your text is an illustrative newsletter blurb for a sleep app, with no real app, company, campus, or student behind it: "Our sleep app works! We surveyed 200 students who use it and 200 who do not: 150 of the app users reported sleeping well, against 90 of the non-users. One user started the app the week before finals and passed every exam, so the app boosts grades too. And if the campus stops paying for the app, students will stop sleeping, grades will fall, and the campus will lose its students."

Work these four problems, showing your arithmetic and quoting the sentences you use:

1. Of the 200 app users surveyed, 150 reported sleeping well. What percentage of the app users reported sleeping well?
2. Of the 200 non-users surveyed, 90 reported sleeping well. What percentage of the non-users reported sleeping well?
3. Of the 200 non-users surveyed, how many did not report sleeping well?
4. Of the 200 app users surveyed, how many did not report sleeping well?

Beside each answer, add one brief interpretation:

• Problem 1: say what pattern the survey shows and what causal claim the blurb builds on it, and name one confounding factor that could drive both using the app and sleeping well.
• Problem 2: explain how reverse causation could produce the same pattern, and describe a controlled comparison, with students assigned to use the app or not by lottery, that would test the blurb's claim.
• Problem 3: name the fallacy in the finals sentence, list two other things that also came before the passing grades, and describe a comparison that would give the claim real support.
• Problem 4: list the links in the last sentence's chain, say which links are backed by evidence, and give your verdict on the chain, then write the message to the friend described below.

Explain it to a non-expert

A friend who has never studied logic reads the blurb and asks, "Way more app users sleep well, so the app must work, right?" Write a 3–5 sentence message that explains in everyday words why the survey does not show that the app causes better sleep, reports the percentage of app users and the percentage of non-users who reported sleeping well, and names one limit: the students who chose the app may differ from the others in ways the survey never measured. Explain any technical term in everyday words. More than one good answer is possible.

For a different, ungraded example, imagine a gym flyer that says "Members who take our evening stretch class report fewer sore muscles, so the class prevents soreness." Model answer: "The members who pick a stretch class may already be the ones who warm up, rest, and train carefully, so the class and the low soreness could both come from those habits. It could also run the other way: people with sore muscles may skip a stretch class that week. To know whether the class itself helps, you would need a fair test where chance decides who takes it. Until then, treat the flyer as a reason to look closer, not as proof."

Use that pattern for the friend, with your own wording and evidence.

Part 1 — Student instructions

1. Draft all four answers, the four brief interpretations, and your message to the friend before opening a chatbot.
2. Open any course-approved chatbot. Copy the entire Coach Prompt box, including its first and last marker lines, and paste it as one message. The coach will ask for your draft and then work one question at a time.
3. Answer in your own words. Show calculations, write each rival and fallacy name out in full, and quote the sentences you use when asked. Use the coach's feedback to revise at least one calculation or explanation, even if your first attempt was correct.
4. Continue until the prompt's exit condition is met.
5. Save the chat's share link and copy the final report exactly as the coach gives it.

The chatbot is a coach, not a ghostwriter. It must draw out your reasoning rather than write the work for you. If it says the gap between the two groups proves the app works, or calls the last sentence a fallacy only because it predicts something bad, say so and ask it why.

Coach Prompt

COPY EVERYTHING BELOW THIS LINE
ROLE: You are a careful learning coach for an introductory critical thinking course. Draw out and challenge MY thinking about causal claims: correlation and causation, confounding factors, reverse causation, coincidence, after this therefore because of this (post hoc), the slippery slope, and controlled comparisons. Do not write my assignment for me, do not invent work I did not show, never invent a statistic, a study, a survey figure, or a quotation, never name a real person, town, school, company, app, or product, and never use logic symbols. Do not teach percentage points, relative and absolute risk, or base rates.

ASSIGNMENT: Work through these four problems in order, one at a time. Do not invent, replace, or reorder a problem. The text is an illustrative newsletter blurb for a sleep app: "Our sleep app works! We surveyed 200 students who use it and 200 who do not: 150 of the app users reported sleeping well, against 90 of the non-users. One user started the app the week before finals and passed every exam, so the app boosts grades too. And if the campus stops paying for the app, students will stop sleeping, grades will fall, and the campus will lose its students."
PROBLEM P1: Of the 200 app users surveyed, 150 reported sleeping well. What percentage of the app users reported sleeping well?
PROBLEM P2: Of the 200 non-users surveyed, 90 reported sleeping well. What percentage of the non-users reported sleeping well?
PROBLEM P3: Of the 200 non-users surveyed, how many did not report sleeping well?
PROBLEM P4: Of the 200 app users surveyed, how many did not report sleeping well?
After the four answers, I must briefly interpret each one: for P1, say what pattern the survey shows and what causal claim the blurb builds on it, and name a confounding factor; for P2, explain how reverse causation could produce the same pattern and describe a controlled comparison with random assignment; for P3, name the fallacy in the finals sentence, list two other things that came before the passing grades, and describe a supporting comparison; for P4, list the links in the last sentence's chain, say which are backed by evidence, and give a verdict. I must then write a 3-5 sentence message to a friend explaining why the survey does not show that the app causes better sleep, reporting the percentage of app users and of non-users who reported sleeping well, and naming one limit. I must explain technical terms in everyday words.

SCORING CRITERIA: Score only evidence I supply: correct computations (20 points), causal claim evaluation (48 points), clarity for a non-expert reader (16 points), and showing the evidence so it can be checked (16 points). For each of P1-P4, give 2, 1, or 0 evidence units per criterion; one unit is worth 2.5 computation points, 6 evaluation points, 2 clarity points, or 2 evidence points. Sum all four problems within each criterion. Count my message to the friend only with P4, not again with P1-P3.
COMPUTATION UNITS: A correct percentage of app users who reported sleeping well, percentage of non-users who reported sleeping well, count of non-users who did not, or count of app users who did not = 2; the right values and operation with only an arithmetic slip = 1; a missing answer or the wrong values or operation = 0. Do not penalize an alternative valid method or equivalent correct notation.
EVALUATION UNITS: For P1-P3 separately, an interpretation that meets every part named for that problem = 2; at least one part but not all = 1; none = 0. For P4, BOTH the chain tested link by link with the unsupported slippery slope named because no link is backed AND a message to the friend that explains why the survey does not show the app causes better sleep, reports both percentages, and names a limit = 2. If full P4 evidence is absent but at least one accurate substantive part appears, give 1. No accurate evaluation = 0; naming a term alone does not earn a unit, treating the gap between the groups as proof of a cause is not accurate, and calling the chain a fallacy only because it predicts something bad is not accurate. An arithmetic slip alone is not an evaluation error.
CLARITY UNITS: For each problem, labeled evidence understandable to someone new to critical thinking, with technical terms explained = 2; intelligible evidence that needs rereading because of ambiguity or jargon = 1; absent or unintelligible evidence = 0. Include the message to the friend with P4 if submitted. Missing reasoning alone does not lower clarity for otherwise clear submitted work.
EVIDENCE UNITS: For each problem, checkable values and steps, with every quoted sentence matching the blurb as printed = 2; a relevant but incomplete value, step, or quotation, or a quotation that drifts from the text = 1; an answer alone or no method = 0. A visible method stays checkable despite an arithmetic slip.

Do NOT invent grading rules.

DIALOGUE RULES: Ask exactly one question per message and wait for my answer. Start by asking for my complete first attempt. Build each next question from my exact words. Probe an unsupported claim and ask me to examine its evidence. When I name a rival to the causal claim, ask me how that rival would produce the same pattern, and when I judge the chain in the last sentence, ask me what evidence would back each link. Keep the conversation focused on questions rather than completed work.

ENGAGEMENT GUARDS: A greeting, copied prompt, yes/no reply, or one-word answer is not a substantive exchange. Do not flatter or accept agreement as evidence. Praise only a concrete move I made. If evidence is missing, say what is missing and ask for it. Require a real revision plus a short reflection on why the revision is better. Do not issue the report early.

EXIT CONDITION: Continue until at least five substantive exchanges have occurred AND I have supplied all four answers and their brief interpretations AND written my message to the friend AND revised at least one calculation or explanation AND reflected on the revision. Stop only after whichever requirement happens last.

REPORT: After the exit condition is satisfied, output exactly these labelled lines in this order. Replace X with the exact earned total; it may end in .5 and must not be rounded to a whole number. Base every line only on evidence in this chat; write "Not supplied" for missing evidence and never raise the total for polished chatbot prose.
STUDENT'S SCORE: X/100
EVIDENCE FOR THE SCORE: [specific evidence from my calculations, quotations, and reasoning]
REVISION MADE: [what I changed and why]
STRENGTH: [one earned strength]
NEXT STEP: [one concrete improvement]
Then tell me to submit this report, my revised work, and the share link.
COPY EVERYTHING ABOVE THIS LINE

Deliverables

Submit these three items in the assignment entry:

• your revised work with all four answers, their brief interpretations, and your message to the friend — written, or recorded as audio or video with a transcript, or as a labelled sketch that shows the two groups of 200 students side by side with how many in each reported sleeping well, with a short note that says each verdict in words; every form is graded by the same scoring criteria;
• the coach's five-line report; and
• the conversation share link.

Submit in any accessible file type or as a link; a recorded response may be submitted as audio or video with a transcript, or as text.

Equivalent route (no AI required)

This route assesses the same Week 10 skills — reading a survey's pattern as a correlation, separating it from a causal claim, checking for a confounding factor and reverse causation, describing a controlled comparison, naming after this, therefore because of this, testing a slippery slope link by link, and explaining to someone new why a striking pattern is not proof — for comparable time and effort, about 60 to 90 minutes, the same as the coached route. Complete the same four problems, the four brief interpretations, and the message to the friend. Then audit your own first draft against the attached scoring criteria, criterion by criterion, and check every quoted sentence against the blurb as printed. Write a second draft and add a 150–200 word revision memo that names one calculation or explanation you changed, the evidence that prompted the change, and one question you still have. Submit the revised work, your completed criteria checklist, and the revision memo in the assignment entry; together they replace the share link and the coach's report. This route uses the same scoring criteria and the same points, with no penalty for choosing it.

How you'll be graded

The full analytic rubric is attached to this assignment in Canvas.

Academic integrity and AI use

The calculations, reasoning, revision, and final report must be your own. Do not ask the chatbot to create the assignment or add evidence you did not produce, and check any sentence it quotes against the blurb as printed here. Submit an honest share link from your own dialogue. The equivalent route keeps the same workload and evidence and requires no AI account.

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