{"id":"dat-col-textbook-buy-rent-digital","audience":"college","category":"decisions","technique":"context","title":"Compare buying, renting or going digital for a textbook","free":false,"task":"You need the Econ 201 textbook. Your professor requires the online homework code, which comes with the digital version or costs $60 on its own. You can resell a bought book at the end for 40% of its price. Write exactly 3 numbered lines, one per option, each showing the real semester cost, then one unnumbered last line: Get: [option]. Plain text, under 70 words.","materialLabel":"Your textbook price notes (attached to your prompt automatically)","material":"ECON 201 - Principles of Macroeconomics, 9th ed. (Halvorsen & Pike)\n\nOptions I found:\n1. Buy new (campus bookstore): $180\n2. Rent print (Bookhop rental, full semester): $95, return by Dec 20\n3. Digital edition (publisher site, 180-day access): $70\n\nNotes:\n- Syllabus: \"Weekly homework is completed online through the publisher's platform.\"\n- My roommate says I can \"just use the library copy\" - it's 2-hour reserve only.\n- Bookhop charges a $25 late fee if the return is late. I'm always on time.\n- Used copies are the 8th edition; prof says chapter numbers changed.\n- Bookstore buyback is usually around 40% if the edition is still current.\n- Shipping for the rental is free over $35.\n- I like highlighting, but the digital version lets you highlight too.","rules":[{"type":"numberedItems","count":3},{"type":"plainText"},{"type":"maxWords","max":70}],"mistakes":[{"title":"Not mentioning the homework code","why":"The AI compares sticker prices and misses that print needs a $60 code.","fix":"Add: \"Homework code is required: included with digital, $60 otherwise.\"","checks":["r0","r1","r2"]},{"title":"Forgetting resale","why":"The AI treats buying as a full $180 loss.","fix":"Add: \"I can resell a bought book for 40%.\"","checks":["r0"]},{"title":"Not asking to see the work","why":"Three pricing styles are easy to mix up.","fix":"Add a line to copy: \"1. Buy: $180 − $72 + $60 = $168\"","checks":["numberedItems","r0"]},{"title":"Trusting the AI to count words","why":"AI is bad at counting. Ask for a total word limit and it often lands over it.","fix":"Cap each line: \"each line under 14 words.\"","checks":["maxWords"]},{"title":"Forgetting where it goes","why":"AI loves markdown tables and bold, which show up as clutter in your budget notes.","fix":"Add: \"Plain text, no bold, headings or tables.\"","checks":["plainText"]}],"promptHints":[{"label":"Mentions the code","patterns":["code","homework","\\$?60"]},{"label":"Mentions resale","patterns":["resell|resale|buyback","40\\s*%"]},{"label":"Asks to show the math","patterns":["show (the |your )?(math|work)","x \\$|\\bx\\b.{0,10}=","calculation","step"]},{"label":"Sets a word limit","patterns":["\\d+\\s*words","word (limit|count)","under \\d+"]},{"label":"Asks for plain text","patterns":["plain","no bold","no markdown","no formatting","no (headings|tables)"]}],"hint":"The cheapest sticker price isn't the cheapest semester. Tell the AI about the required code and resale value.","rubricLabels":["Buy new is $180 − $72 resale + $60 homework code = $168","Rent is $95 + $60 code = $155, and digital is $70 with the code included","The last line picks digital, after the three lines, with nothing before the first numbered line"]}