{"id":"acct-systematic-sample-selection","audience":"accounting","category":"finance-work","track":"finance","technique":"constraints","level":"intermediate","title":"Select every fourth invoice for a sample and total it","free":false,"task":"You're selecting a systematic sample of 5 invoices from a population of 20 for an audit test. Write a prompt for plain text with lines starting \"Interval:\", \"Selected:\", \"Key items:\" and \"Total selected:\". Interval is population divided by sample size. Start at the random start given, then take every interval-th invoice. Key items (over $3,000) are tested separately; list them but don't add them to the sample. Under 80 words. No bullets or numbering.","materialLabel":"Invoice population and sampling notes (attached to your prompt automatically)","material":"INVOICE POPULATION - Oct 2026 AP invoices, numbered 1 to 20 in posting order\n\n# : Amount\n1: $120   2: $450   3: $980   4: $75   5: $1,200\n6: $310   7: $2,150   8: $640   9: $90   10: $1,750\n11: $405   12: $820   13: $55   14: $3,100   15: $260\n16: $1,480   17: $700   18: $95   19: $1,125   20: $530\n\nSampling plan: systematic selection, sample size 5, random start = invoice 3 (drawn by the audit senior). Interval = population / sample size. Key items: any single invoice over $3,000 is tested 100% separately and is not part of the sample.\n\nNote: a staff member suggested also adding invoice 7 'because it looks large'. The plan does not call for judgment picks.","rules":[{"type":"plainText"},{"type":"maxWords","max":80},{"type":"maxBullets","max":0}],"promptHints":[{"label":"Names the four lines","patterns":["interval:","selected:","key items","total selected"]},{"label":"Gives the start and interval","patterns":["start.*3","every 4th","20 / 5"]},{"label":"Separates key items","patterns":["key items","over \\$3,000"]},{"label":"Bans judgment picks","patterns":["(no|don'?t).*judgment"]},{"label":"Caps length","patterns":["\\d+\\s*words","plain"]}],"mistakes":[{"title":"Adding invoice 14 to the sample","why":"The AI includes the large invoice in the sample.","fix":"Add: \"Key items are listed but not part of the sample.\"","checks":["r2"]},{"title":"Wrong sequence","why":"The AI starts at 1 or uses interval 5.","fix":"Say: \"Start at invoice 3 and take every 4th: 3, 7, 11, 15, 19.\"","checks":["r0"]},{"title":"Judgment picks","why":"The AI adds invoice 5 or 10 because they look large.","fix":"Add: \"No judgment picks.\"","checks":["r2"]},{"title":"Markdown extras","why":"The AI adds bold labels, headings and a closing note.","fix":"Say: \"Plain text, no bold. Output only the lines asked for.\"","checks":["plainText","maxBullets","r1"]},{"title":"Trusting the AI to count words","why":"AI is bad at counting and runs past word limits.","fix":"Ask for fewer words than the real cap and keep each line short.","checks":["maxWords"]}],"hint":"A systematic sample follows an interval from a given start. Give both, and keep key items separate.","rubricLabels":["The line starting \"Interval:\" shows 20 / 5 = 4 and the line starting \"Selected:\" lists invoices 3, 7, 11, 15 and 19","The line starting \"Total selected:\" shows $980 + $2,150 + $405 + $260 + $1,125 = $4,920","The line starting \"Key items:\" lists invoice 14 ($3,100) separately, and the output doesn't add judgment picks"]}