SigmaQuest: Learn Statistics

SigmaQuest turns a full statistics course into something you can actually finish. It starts at "what is a variable" and ends at chi-square, regression, and the ways a real study goes wrong. Everything works offline. No account, no sign-up, nothing to log into. THE COURSE • 16 units, 112 lessons, 671 questions — the whole AP Statistics syllabus, plus a closing unit on p-hacking, Simpson's paradox and charts that lie • Seven kinds of question, not four: multiple choice, true/false, fill in the blank, matching, a numeric keypad for the ones you have to actually compute, and two kinds of chart question • Charts are drawn live inside the question — histograms, boxplots, dotplots, scatterplots and normal curves, not pictures of them • Every question you miss comes back on a spaced-repetition schedule that widens as you get it right, and only leaves once it has survived weeks THIRTEEN COURSES, ONE CURRICULUM Pick AP Statistics, a college intro track, a cram list for a STAT 101 final, or a single topic — probability, distributions, regression, inference, data literacy. Progress carries across all of them, because they are all views onto the same lessons. A 12-question placement check can skip you past what you already know. PRACTICE EXAMS Timed, and stratified by unit so no single topic can take over the paper. Choose a 15-question warm-up, a 25-question half exam, or the full 40 questions in 90 minutes. The AP paper comes back with a projected 1–5. THE LAB Six games that drill the parts people lose marks on: Stat Blitz, Sudden Death, Match Madness, Center Stage, Spread Duel and Word Scramble. None of them costs you a degree of freedom. THE FIELD STATION A farm where nothing grows on a timer. A correct answer — anywhere in the app — is the only thing that waters a crop. Every crop's yield is a named distribution printed on the seed packet, and the Almanac plots your harvests against the truth, so you can watch a sample mean converge on μ instead of being told that it does. Fisher worked out randomised blocks counting yields in plots; here the farm is the apparatus, not a mini-game bolted on. THE REFERENCE SHELF A formula sheet, a glossary, a t table, and a normal table you can slide: pick any z and watch the area under the curve move, computed exactly rather than read off a rounded page. Looking something up never costs you anything. THE CREW Ten characters, each with a perk that changes how a session actually plays and a voice that comments on it, plus eight themes. Unlock them by studying, or skip ahead with an optional purchase. Lessons run on df — five degrees of freedom that refill over time. Games, reviews and the reference shelf never spend any. WHAT IT DOESN'T DO No servers, no account, no sign-up. Every lesson, exam, game and reference table works with the network switched off. Progress syncs between your own devices through your own iCloud account, and never passes through ours. SigmaQuest is free and carries ads. It asks before anything is personalized, and declining changes nothing about how it plays. No ad ever interrupts a question, and no ad is ever required to keep studying. AP® and Advanced Placement® are registered trademarks of the College Board. SigmaQuest is an independent study aid and is not affiliated with, endorsed by, or sponsored by the College Board.