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About BSc EOR Wiki
An idea at a time.
A connected way to study.¶
A learning companion for Econometrics and Operations Research at the University of Groningen. Find a definition, work through an example, and follow the connections that make a difficult step understandable.
Use the Wiki alongside your course materials. Your lecturer's syllabus and assessment guidance remain the reference for your course.
Choose a useful first step
Start with the task in front of you.¶
01 / Getting started
Find your place in the course.¶
Open the course hub, choose your lecture or week (or the By topic view, which groups the same concepts by subject), and start with one concept. Read its definition and example before exploring further. Where a course has worked exam problems, its Practise section links to them.
02 / Studying & revising
Turn a gap into a next step.¶
Find the topic, try recalling it, and follow a prerequisite when an explanation stops making sense. Use your study record to choose what to revisit.
03 / Teaching & tutoring
Prepare the foundations.¶
Inspect what a concept assumes and where it is used next. Check its sources against your learning outcome before choosing an example or activity.
Where the notes are strongest. Year 1 has the most developed concept coverage. Pages connect definitions, intuition, examples, prerequisites, related ideas and sources where available. Year 2 has concept notes for Math V, Life Insurance, Game Theory and Risk Insurance, each with figures and AI checks; the other hubs say where notes have not yet been written. Year 3 has four Stochastic Models foundation notes. A course link is not a claim of complete coverage.
Find the right part of the material
Search broadly. Then narrow the question.¶
A title, a course or a teaching unit¶
The header search accepts concept names, aliases, course codes and lecture tags. It also recognises concept names in Chinese, Dutch, German, French, Spanish, Italian, Polish and Romanian; when a search finds nothing, the results page can offer Did you mean …? with the English term. m1c (or M1) identifies Math I: Calculus; m1c-lecture02 narrows to Lecture 2.
Keep the search inside your course¶
Course search limits matches to that course. The Math I–IV hubs organise 37 lecture or week entries.
Keep a set for the next tutorial.¶
Save selected Finder concepts as a named study set for tutorial preparation, revision or teaching. Reopen it, add a note, reorder the concepts or remove items. Each set keeps the selection and order you saved.
Study sets stay in this browser, in the current local account workspace. Account cloud sync and Account backups do not include them. Use Library backup (.json) for all saved sets, or Set backup (.json) for the current set or unsaved draft. Preview a backup before importing it as new sets. Set notes (.md) provides a readable list, not an importable backup.
If local account storage is unavailable, you can still preview and download a draft. Named study sets are unavailable in Exam Mode.
With Account connected, Share with a connection sends a saved set to one of your study connections. It reaches them as a notification; Copy to my study sets opens it in their Finder as an unsaved draft, leaving out any concept that is no longer published, and they choose whether to save it.
Review sessions use 5 or 10 concepts from a set, in its saved order or up to its available count. Done and Skip describe that session, separate from mastery ratings.
Review sessions are saved in this browser and are unavailable in Exam Mode. Resume restores the concept queue and your position; it does not restore an unfinished AI question set. Session completion does not change mastery or award extra XP. AI checks and mastery ratings keep their existing records.
Practise with worked exam problems¶
Math I has worked problems from the mock exam and weekly tests. Each gives a short plan and folded steps with marks; every step links to the concept page it uses. The Problem connections panel on the right lists What you need (the concepts the problem uses) and Try next (the next problems to try); on phones and narrow windows these two lists sit below the problem. Open the problems from the course's Practise section or the sidebar's Worked exam problems link; on a problem page the left sidebar shows each course as a card listing its problems. They are practice, not a preview of the live exam, and are not in Exam Mode.
Personal evidence, practical next steps
Notice what needs another attempt.¶
Course diagnostics starts with four short lists: Weak by evidence (mastery below 50), Prerequisite gaps (concepts you have started whose foundations are shaky), Due for review (once strong, but the last evidence is over 30 days old) and No evidence yet. Below them, every concept is listed by teaching unit. Opening a page is not evidence. Open it from a course page and choose a manageable review target. My → Study → Progress shows the same numbers for all your courses side by side, each with a link to its diagnostics.
AI mastery checks need an internet connection to check your answers; an account is optional for practice. Questions and options load first; the correct answer and explanation arrive after you submit. If checking fails, your selected answer stays in the open quiz for Retry check answer. A question updated since you loaded it requires a fresh page before starting another check. These repeatable learning questions support practice and friendly rankings; they are not a confidential examination bank.
Your mastery rating¶
Rate a concept after trying to explain or use it. Your ratings and your AI-check answers together form the concept's mastery score (0–100); recent and more reliable evidence counts more, and older evidence fades with a 60-day half-life. One rating alone moves the score only part of the way: a single Mastered reads about 68. With too little evidence the page shows Mastery: no evidence yet. The same score appears in diagnostics, maps, Learning Path and the Concept Galaxy.
Open the information button beside My understanding for this guide while studying. Course diagnostics uses the same initials: M, C, P and U. An unrated concept is separate from Unknown: visiting a page alone does not choose a rating. Not assessed in prerequisite readiness means that none of its prerequisites has evidence yet: no rating and no AI-check answer. A prerequisite without evidence counts as 0 in the readiness percentage.
Practise before you reveal¶
Random revision moves through a chosen pool of concepts.
Self-test opens content folded so that you can attempt recall before reading the explanation.
AI-test uses an available AI mastery check as the next step. Availability depends on the concept.
A check is a prompt to think¶
Some concept pages offer a short AI-generated multiple-choice check. Your answers count toward the concept's mastery score as soon as the result is saved, and the result shows the change, for example Mastery 41 → 58. Harder questions count more, a timed-out answer counts as wrong, and a repeat check within seven days counts half. The result also suggests a self-rating; choose Use as self-rating only if it matches your own judgement, and compare explanations with the course sources. The optional timer choice is remembered in this browser. With a connected account, server-confirmed repeat checks earn XP subject to the daily limit, pay EORbits for one check per concept each UTC week (Monday to Sunday), and count once per concept per UTC day towards quiz badges. Guests can practise and get feedback online, but imported guest results do not later earn cloud rewards. Checking needs internet even if questions have loaded. Once you have shown you know a concept, its answers move your EOR Rating only a little.
No evidence on the prerequisites yet? Readiness says Not assessed, rather than implying a failed 0% result. Rate a prerequisite or take its AI check to begin your own assessment.
Readiness is a personal study indicator. It is not a course grade, a predicted exam mark, or a report about a class. A visit is never evidence; a short AI check adds limited evidence, not proof of understanding.
Self-ratings earn no XP or EORbits from 17 October 2026. They count only as study evidence; AI checks keep their usual rewards and limits.
When the missing step is elsewhere
Follow the connection back.¶
Concept connections, Concept maps and Learning Path expose recorded prerequisites, later uses and possible routes towards a target.
Nearby starts with the current concept, its direct prerequisites, up to ten direct dependents, and related concepts. When there are more than ten dependents, the same ten appear across visits and devices. All three maps use the same fixed concept positions and connected course regions. Nearby shows only the current neighbourhood and any neighbours you explicitly expand; expanding does not reshape the course borders. Prerequisites and Dependents show the wider study routes; switching between the three tabs keeps your place on the map, and on wider screens the Prerequisite map and Dependent map buttons under Concept maps open those views directly. Optional map enhancements may require an unlock or an active trial; the interface shows their availability. The 3D view inside concept maps is paused while the maps are being refined; the separate Concept Galaxy shows the whole programme in 3D. The underlying page links remain useful when you prefer to read directly.
On phones, map tabs and view controls share the top row; zoom controls sit at the bottom. Drag to pan and pinch to zoom. In Nearby, selecting a node offers Expand map and Open page; a concept on this page's prerequisite or dependent chain also offers Route, which draws the path between it and this page in the Prerequisites or Dependents view. Reduced-motion preferences skip the expansion animation.
Knowledge masking hides unfamiliar concept titles by default; it does not remove their nodes or links. Nearby always starts with the current page and its direct neighbours. Expanding a neighbour adds surrounding concepts temporarily; closing the map clears those expansions. Hovering or selecting alone does not expand it.
Turning Knowledge masking off shows the titles, but does not add more nodes. Your visits and self-ratings remain in your learning record; clearing a rating changes your learning status, not the size of Nearby.
Collection capsules count what you have opened, not what you know. Under each week or lecture name a capsule shows concepts opened out of the total, with a progress ring; it turns gold with a ★ once every concept of that week or lecture has been opened. Under the course name a capsule counts the whole course and its completed weeks or lectures. On each concept, a green tick means you have opened its page and a yellow dot means you have not yet. Opening is read from your learning record on this device; capsules earn no XP.
BSc EOR Passport. My → Account → BSc EOR Passport (connected account) gathers the same record into one page: a pixel map of every course, where the fog lifts around each concept you have opened, in that course's colour. Each course is labelled with its code, and a key under the map lists every course with its colour and name, including those you have not opened yet. Tap a course to see its weeks or lectures and each concept. Explored counts opened concept pages; Mastery colours the map by your mastery scores; Level is your activity XP. None of these is a course grade. Share draws a passport card in your browser for the Moment share panel; your name is optional and mastery is left off the card unless you add it. The card ends with the same course key, with each course's opened / total; untick Course key for a shorter 4:5 picture. On a phone, WeChat and Instagram copy the picture and open the app, where you paste it into a chat or post. The QR code and link point to the wiki home page and carry no account information.
With a connected account, choosing Expand map to reveal more concepts can also reveal treasure, whether Knowledge masking is on or off. Open Map tips for a reminder, or read the treasure rules below.
Concept Galaxy. Enter the Concept Galaxy to fly through every course in 3D: each course is a constellation, each lecture or week a cluster and each concept a star. Stars you have visited shine brighter, and stars with mastery evidence shine fully. It is for exploration and earns nothing.
- 01
Locate a gap
Which step can you not explain? - 02
Revisit a foundation
Read its definition and try an example. - 03
Return to the problem
Test whether that connection helps.
Discover treasure as you explore.¶
With a connected account, explicitly choosing Expand map in Nearby gives you a chance to discover a chest when that action adds new concepts. You can expand a concept you have not yet opened or rated; Knowledge masking only controls whether unfamiliar titles are hidden. Each expanded concept gives that account one chance per UTC day, shared across devices. There is no daily limit on how many chests you find or open. Opening Nearby, hovering or clicking a concept without choosing Expand, refreshing or moving the map, switching views and following a learning path do not give extra chances. Guest browsing and the Exam site have no treasure rewards.
| Chest | Chance per eligible expansion | Guardian | XP + EORbits | Extra reward |
|---|---|---|---|---|
| Crown | 3 in 1,000 | Always: three challenge questions | 34–46 XP + 50–70 EORbits | Three permanent shop items: one priced 450–650, one priced 160–240 and one avatar initial style |
| Gold | 2 in 100 | 75%: one challenge question | 12–18 XP + 20–30 EORbits | One permanent shop item priced 160–240 |
| Silver | 51 in 1,000 (about 1 in 20) | 40%: one standard question | 4–6 XP + 6–10 EORbits | 30% chance of one permanent shop item priced 100–150 |
| Bronze | 126 in 1,000 (about 1 in 8) | 15%: one basic question | 1–3 XP + 1–3 EORbits | 10% chance of one avatar initial style |
In all, about one eligible expansion in five finds a chest. At most one chest appears per expanded concept and day, and repeating the same expansion that day does not reroll it. Open a chest before you leave the map: leaving with a chest still unopened gives it up (the map asks first), and unopened chests also expire at midnight UTC.
Chest guardians. Opening a chest may wake a mimic that guards it, but only on a concept that has AI quiz questions. Its questions come from that concept's own AI quiz and are timed like the quiz (20, 30 or 40 seconds). Answer correctly to win the chest; a wrong or late answer lets the mimic keep it. A crown guardian asks three challenge questions and pays a third of the crown's reward, including one of its three items, for each correct answer; those three answers also count as a completed AI check on that concept.
You can also give up. Before a question is shown, giving up costs nothing and the chest simply disappears. With a question on screen, giving up counts as a wrong answer: the chest disappears and your EOR Rating drops. Giving up a crown between its questions keeps the thirds you have already won.
Every guardian answer is a rated AI quiz answer: it can raise or lower your EOR Rating against the question's difficulty, with one and a half times the quiz's usual step, and it shares the quiz's 40 rated answers a day. A question you have already answered, in the AI quiz or another battle, is not rated again. Each correct answer also earns 1 XP. Guardians never change your self-rated mastery and pay no extra EORbits.
Opening a chest asks the server to confirm XP, EORbits and any item rewards. Reduced-motion preferences skip the animation. XP and EORbits are drawn evenly from the ranges above. An item can be any single permanent shop item in the chest's price band (the base shop price, before discounts): fonts, cursors, sound packs, music, quiz celebrations, effects, themes, map styles and more, so the choice grows whenever the shop does. Complete theme editions and bundles are not chest prizes. The draw prefers items you do not own yet, including ones waiting in another unopened chest; only when you own the whole band can a chest hold a duplicate. Items are unlocked for later use; your appearance is not changed automatically.
Already own a rewarded item? It is converted into EORbits at its current shop price when you open the chest, including any current discount. If opening fails, use Retry to claim the same chest; retrying does not reroll or pay twice. Chest XP is a bonus: it does not increase Most Active totals, learning achievements or study-day counts, and does not generate additional XP-to-EORbits income.
For teachers & tutors
Review the assumptions behind an explanation.¶
The Teaching workbench reviews one concept or a whole lecture or week, using published page tags. See the selected concepts, their direct and earlier foundations, connections within the lecture, and downstream uses. Add a learning outcome and preparation notes, then download or print the review. The list follows concept titles; use the recorded dependencies to check your teaching order.
It reads the Wiki's published prerequisite links. It does not edit the curriculum, evaluate students or produce class analytics. Check the linked definitions and sources against your own course materials; a missing link does not prove that no prerequisite exists.
Your tools, your learning record
Make it your workspace.¶
You can read the notes and use basic search without an account. My is the personal area, in three panels: Account (profile, privacy, alerts, study connections, history and sync), Study (progress in each course, review, study sets and saved pages) and Rewards (collection, Arena and Store). A connected account can sync supported learning records across devices; inspect its sync status to see whether the transfer succeeded.
To keep learning across devices, start at My → Account, follow its account and recovery-code instructions, and check Sync & learning data after connecting another device. Keep your recovery code private.
Use My → Account → Public profile to see the information you share with everyone, including shared achievements and competition honours. Edit profile on that page, or My → Account, opens your account editor. Your public view follows your visibility settings and does not add private records from this browser.
Study together. Accepted study connections can reach each other in a few small ways, each arriving as a notification. On a connection's public profile, Applaud a recent level, achievement, honour or rating milestone. On a concept page, the page menu's Recommend to a connection sends that page with an optional note. In a comment, type @ and the first letters of a name to mention a learner. On any other learner's profile, Pin as rival keeps up to five learners beside you on the user rankings; Rivals then shows just you and them, with the gap. Rival pins stay in this browser and are never sent to anyone.
Local ratings, study history and named study sets depend on this browser's storage. Clearing site data can remove local records.
Supported learning events, quiz history and personal settings can travel between connected devices.
Use the dedicated JSON backup for study sets. Teaching workbench notes stay on that page; download the review to keep them.
What each backup includes¶
| Learning material | Where it is kept | Keep or restore a copy |
|---|---|---|
| Supported account learning events, quiz history and settings | This browser; cloud sync when connected and successfully synced | My → Account → Sync & learning data shows the actual sync/recovery status and account backup actions. |
| Named study sets | This browser's current account workspace; not in account cloud sync or account backups | Open Study sets, use Library backup (.json), then import the file as new sets in the other browser. |
| Current review queue and Done/Skip position | This browser's current account workspace | Resume review. Download its summary to keep a readable record; this does not restore the queue on another device. |
| Teaching review and preparation notes | This page until you leave or reload it | Download Markdown or print the review before leaving. |
A download is a separate file, not a cloud sync. Keep the study-set JSON if you want an importable library; Markdown is a readable study list. A failed sync is not a confirmed backup.
Choose what others can see¶
In My → Account → Privacy, choose Private, Connections only or Public for supported profile sections. “Connections only” means accepted study connections. These settings control visibility; they are not a switch that turns cloud sync into local-only storage.
New accounts currently make User rankings public by default, while the other profile sections default to private. Review your own settings. Public rankings can include your username, level, XP, quiz results, Store spending and EOR Rating; your public profile card shows your EOR Rating beside your level and XP; showing an avatar and intro also requires a public profile. Anyone who finds you in public rankings can open a basic profile card with that username, level and XP.
Arena has separate switches for receiving challenges and sharing your competition record, inside My → Rewards → Arena → Your record. Both Arena switches start on. While invitations are on, learners who find you in public rankings or on your public profile can challenge you. Your competition record is shared only when your profile and rankings are both public, so making a private profile public can also reveal an existing record. Review these switches before changing profile visibility. You can participate without publishing your record. Hiding a record removes it from public display without promoting someone else into a previously awarded title.
Profile comment summaries follow their visibility setting. Comments posted on concept pages remain visible there. A comment can include formulas: choose ∑ beside the comment box to type LaTeX with a live preview, or write $…$ inline and $$…$$ on its own line. Removing an account from this browser signs out here; it does not delete cloud data or public comments.
Personalise the experience¶
My → Rewards → Store uses EORbits earned through study activity. It offers interface and profile themes, fonts, effects and optional study enhancements. Many items offer previews or trials; check the item's description and access label before unlocking it.
Wishlist: use the heart button in the Store or a quick customisation menu for items you do not own. Purchasing or receiving a permanent unlock automatically removes the item from your wishlist; owned items can still be gifted to friends. Your wishlist follows your connected account, and My → Notifications alerts you when a wishlist item goes on sale. Each distinct account contributes a 0.5% independent chance for that item to enter the next day's bonus-offer draw. Daily offers change at midnight Dutch time (Europe/Amsterdam). At most three bonus offers are selected, in addition to the usual daily offers; adding and removing an item repeatedly does not stack chances or change today's offers. Wishlist interest improves the chance, not a guarantee of a discount.
Try: a preview lasts two minutes. Each item can be tried once every seven days, across your connected devices. Pausing or switching a preview does not restart its timer or cooldown.
Gift to a friend: permanently unlock a catalogue item for an accepted study connection, even if you already own it yourself. You pay 70% of its current price, including that day's discount, rounded to the nearest whole EOrbit (minimum one). The recipient receives a notification and has 7 × 24 hours to choose Receive gift; receipt adds the item to their Collection Value at its current undiscounted market value. Sending does not require advance approval and does not transfer your own copy. Consumables, random bundles and personalised uploads are excluded.
If the recipient already owns the item, including buying it after the gift was sent, the actual payment is returned to the sender. Declining, expiry, removal of the connection or withdrawal of the product also closes the gift with a refund. There can be only one pending gift per recipient and item. Gifts follow account identity through renames; a replacement account with the same name cannot claim them. Deleting an account closes its pending gifts; refunds go only to a surviving original sender account. Expired gifts cannot be claimed; automatic processing runs every 15 minutes and also checks when the gift list is opened. Store → Gifts shows sent and received gifts.
XP tracks your activity progression; EORbits are the spendable balance shown in the Store. Open My → Rewards → Collection for course achievements, account badges, monthly honours and Arena honours. Choose three collected rewards for your showcase; competitive honours have their own display area.
Activity is not academic performance¶
Rankings show activity and engagement across the Wiki. XP, EORbits, visits and public quiz signals are not course grades or an academic ranking. Choose a study target from your understanding and course needs.
Every dated board uses the same windows: Today (from 00:00 UTC), Last 7 days and Last 30 days (each including today), plus All time where it makes sense. Most tested counts answers to a concept's multiple-choice questions anywhere on the Wiki: concept checks, the daily check, map chests, duels and weekend sprints. Hardest concepts shows only first-try accuracy and lists a concept once it has at least 10 graded first tries.
A collection with a story
Keep your milestones. Share a little competition.¶
There is one collection. Personal achievements — course achievements and account badges — recognise your own progress, while competitive honours recognise monthly results, friendly duels and weekend events. Your EOR Rating follows how you perform across AI quizzes, duels and weekend quizzes.
Grow at your own pace¶
Course achievements. Each course with AI checks has its own set, each with its own icon: clean AI checks on linked concepts, streaks of fresh challenge questions, exploring every page of a unit and more. Some stay hidden until earned. They appear on the course page under More about this course and beside its concepts. Each shows how many of that course's learners hold it; one held by 10% or fewer turns gold. Holding a whole set earns that course's Complete Set badge. A clean check is one AI check with every answer right, on questions that are new to you or that you last answered at least 14 days ago.
Account badges mark wider milestones, such as XP, active days, quizzes and courses explored, in tiers, with how many collectors hold each one.
In My → Rewards → Collection, inspect each requirement, see your progress and earned date, and choose three favourites for your showcase. You do not need to beat another learner to complete a personal achievement.
Measure yourself with the EOR Rating¶
Your EOR Rating is one Elo-style score that starts at 1200. Every rated result counts as a game against an opponent rating, so a harder success earns more and an easier miss costs more.
- AI quizzes: a basic, standard or challenge question counts as a 1000, 1200 or 1400-rated opponent. Only your first server-reserved attempt at each question counts, up to 40 reserved questions per UTC day. Leaving a question uses its reserved slot; later practice neither adds nor subtracts Rating. Connect your account before starting to receive rated questions. At 1200, a correct challenge answer adds about 6 points and a wrong basic answer removes about 6. Answers on a concept you have recently shown you know count for less: if your best AI check on that concept in the last 30 days was 3 of 3, a correct basic, standard or challenge answer adds only about 1, 2 or 3, and a best of 2 of 3 counts three-quarters as much. Only your best check counts, so a deliberately poor check never makes a concept worth more again. Older score-only sessions already held by the server keep their one-time standard-tier history; newly imported summaries do not earn Rating.
- Duels and ghost races: the other player's rating is the opponent. Beating an equal player adds 20. The same two players are rated at most three times in a rolling seven-day window, counting both kinds together.
- Weekend events: after an event closes, a ten-question Quiz Sprint weighs the same as five games against a 1500-rated opponent. Each question gives credit for its share of the ten points it can earn. Historical puzzle events keep their original rating rules and results.
Current ranks by the standing rating; Today, Last 7 days and Last 30 days rank by how far the rating moved inside that window, and a losing window is listed rather than hidden. One rated result puts you on Rankings → EOR Rating, following your ranking privacy setting, so practising alone is enough to be ranked; under ten results the rating is marked provisional. Rated answers are checked against the server's question bank. The study questions and answers are public, so Rating is a friendly learning signal, not a grade.
Revisit a month's best¶
On the Most active users and EOR Rating boards, Monthly honours sits between Last 30 days and All time. Browse past champions for XP earned or Rating gained; each row shows the month's trophy, learner and winning score. Honours use completed UTC calendar months; winning scores are frozen and every tied winner shares the title. A month with no eligible positive score has no champion for that metric, with the reason shown on the board.
The live Last 30 days tab currently covers the most recent 30 days. It can therefore differ from a completed calendar month's frozen honour score.
Monthly trophies appear in your collection and public profile when shared. Choose up to three personal achievements or monthly honours for your showcase. Repeated wins of the same monthly title share one slot and appear as stacked medals with ×2, ×3, …; open a medal to see every month you won.
Invite someone to a friendly duel¶
Open another learner's public profile → Challenge. Choose an available course, 10–50 questions, and now or an agreed time within the next four weeks. Times show their time zone. The recipient can accept, decline or counter with a different course, question count or time. Invitations appear as a small notice when the reader is free. Choose Review invitation to open one on this device; Later keeps it in Arena. Signing in elsewhere does not open a table automatically.
Both players press Ready and receive the same question and option order from the existing AI quiz bank. Each question has no answer timer. The first correct answer received by the server wins one point; a wrong option is visibly ruled out for both players.
Agree an optional EORbits stake. Live duels and Ghost races support a whole-number stake of 0–10,000 EORbits per player; choose 0 to play without one. Either player can propose a different amount before acceptance, and the other player must accept the latest proposal. If an invitation asks for more than your available balance, suggest a smaller amount or 0, or decline. Acceptance checks both current balances and holds the same stake from each account together.
The winner receives both stakes. A draw, cancellation, expiry or other no-result ending returns each player's stake. Leaving a started match follows the score rules below: it can still produce a winner, so leaving does not guarantee a refund. Stakes and their returns give no additional XP or EOR Rating and do not count as shop spending or monthly shopping honours.
Mistakes reset on every question. For each player, the first wrong answer on that question gives a 5-second cooldown, the second gives 10 seconds, and the third awards that question's point to the opponent. Both review the explanation and press Next to continue. The match uses total question points, with equal totals recorded as a draw.
If a player does not arrive within ten minutes of the agreed time, the match never started: nobody wins or loses. Rejoin a disconnected live match within 90 seconds. Leaving a started match — choosing Leave match, not reconnecting in time, or not pressing Next within two minutes after your opponent — is judged on the score at that moment. Leave while behind and your opponent wins. Leave with a lead your opponent could not even tie by answering every remaining question and you keep the win. Leave at level scores, or with a lead that could still be caught, and the match ends with no result: no win, loss or rating change. Ten minutes without any answer or Next also ends a match with no result. Answers are ordered by their arrival at the server, so connection quality can affect a close race.
My → Rewards → Arena → Your record shows your EOR Rating, wins, draws, losses, opponents and earned honours. Complete a full duel, win your first one, beat three different opponents or complete duels with ten different opponents to earn the four duel keepsakes. Results decided by someone leaving do not advance these full-duel honours. These are friendly learning games, with public study material, rather than course assessments.
Race a ghost instead. When you challenge someone, choose Ghost race to play at different times. Nothing is played until they accept, within three days. Then each of you has a week to play the same 10, 15 or 20 questions, in either order and whenever suits you; the server times each question from the moment it appears, and wrong answers pause you for 5 and then 10 seconds, as in a live duel. Each question's point goes where a shared table would have sent it: the earlier correct answer wins it, and using up three attempts first hands it to the other player. Whoever plays second races the first player's recorded run, their ghost, and sees its time for a question after finishing that question. Nobody wins because the other player did not turn up: an invitation that is not accepted, a week that runs out before both runs are played, or backing out before starting your run all end with no result. A run that was started and then left, with Leave race or by not answering for a day, is judged like leaving a live duel. A finished ghost race counts like a duel for your record, honours, EOR Rating and completion rewards.
Watch a connection's match. During a live duel, each player can choose Let study connections watch. Watching opens only while both players allow it, and only to accepted study connections of either player, who find it under Connections playing now in Duels. Watchers see the score, and each question only after its point is decided, so nobody can be helped from outside. Players see how many are watching, and either can close watching at any time.
Quiz the courses you are learning¶
Open My → Rewards → Arena → Weekend events and choose Year 1 or Year 2 under Course year; your choice is remembered and existing runs stay saved. Activities run from Saturday 00:00 to Monday 00:00, Europe/Amsterdam, with the following two weekends previewed.
From 26 September 2026, scheduled competitions use a ten-question Quiz Sprint linked to the current block of your course year. Year 1 and Year 2 each cover 2026–2027 semester 1 (blocks 1a and 1b); semester 2 will be added after its course timetable is published.
- During teaching, questions come only from that week's taught topics, using the Wiki's lecture or week labels and the course timetable. A course with no scheduled lecture that week contributes no new topics. Topics spanning several lecture weeks enter the pool in their final labelled week.
- After the block finishes teaching, weekends draw ten random questions from the full available quiz pool of that block until the next block starts.
- Once a new block begins, its courses become the scope. Courses without quizzes are listed but contribute no questions. If weekly topics or enough questions are unavailable, no competition opens for that weekend.
The event shows the included courses and lecture or week scope. Everyone receives the same ten selected questions that weekend, worth 100 points in total. “Full block revision” means ten questions sampled from the block's available pool, not answering every question in that pool.
Which courses contribute questions? Only courses with AI quizzes contribute, and the event card always lists the current scope. In Year 1, block 1a draws on Math I: Calculus and OR Modelling, and block 1b on Math II: Linear Algebra and Probability Theory for EOR. Probability follows six lecture weeks; its former Week 7 material is currently hidden and excluded from quizzes. In Year 2, block 1a draws on Math V: Advanced Linear Algebra; the other Year 2 semester-1 courses do not have quizzes yet.
For example, 26–27 September has no competition because the available quiz course has no new lecture topics that week. 3–4 October covers Calculus Lectures 7–8. From 17 October, weekends revise the available block 1a pool; 7–8 November switches to the first week's topics in block 1b. Year 2 competitions start on 17–18 October with Math V questions. A No competition scheduled card explains a gap: it does not substitute unrelated questions or offer an official run.
All growth from earlier weekends is kept: scores, XP, EORbits, EOR Rating and honours. Events that have already started keep their original format, including the weekend of 19–20 September 2026. Historical Prerequisite Relay, Route Builder and Concept Match events keep their original rules and remain available for practice; they do not rotate into future weekends. Historical puzzle runs have five puzzles worth 20, 12 or 6 points for a first, second or third correct attempt, with hints after misses and zero for a skip or third miss. Their cards and controls still work with keyboard and touch.
A Quiz Sprint run has ten questions, opened one at a time; only one can be open, and its clock starts when it appears. A correct answer earns 6, 3 or 1 points on the first, second or third attempt, plus 4, 3, 2 or 1 more for answering within 10, 20, 30 or 45 seconds, so a quick first answer is worth 10. A wrong answer is crossed out and pauses you for 5 seconds, then 10; a third miss or a skip earns zero. After the run, or once the weekend closes, every question can be reviewed and practised.
The board shows provisional leaders during play. Confirmed weekend champions appear only after closure and settlement, when at least two publicly eligible entrants have answered all ten questions with at least six correct. Historical puzzle events require all five puzzles completed and at least three solved. Highest scores share the title when tied. Weekend honours join your collection and shared competition record.
Choose Mute this weekend to silence that event's wiki reminder, or use Add to my calendar (.ics) to download a file for your own calendar. Muting the wiki reminder does not remove a calendar event you already imported. A completed official puzzle or sprint question with a submitted answer also earns up to 8 XP and 8 EORbits, once each, up to five per UTC day. A normally completed duel or ghost race in which you submitted answers earns the same, up to five per UTC day. Correctness or winning is not required for participation credit. Skipping, practice, matches ended by leaving and matches with no result do not earn these completion rewards. The existing daily XP limits apply; these activities also count towards the existing once-per-day active-day credit. Rewards are confirmed and synced by the server.
A reference to keep handy
Course codes for search¶
These 24 codes are recognised by Concept Finder and the header search. Use a code as a search token; follow its link to the course hub. Progress, the Passport and course badges show the same codes in capitals, with the Math courses shortened to M1–M6 (search finds them either way). This is a search reference, not a list of fully written courses or an official programme specification.
| Code | Course |
|---|---|
i2da |
Introduction to Data Analytics |
m1c · M1 |
Math I: Calculus |
orm |
OR Modelling |
m2la · M2 |
Math II: Linear Algebra |
pt |
Probability Theory for EOR |
prog |
Programming for EOR |
fin |
Finance for EOR |
m3a · M3 |
Math III: Analysis |
micro |
Microeconomics for EOR |
m4mc · M4 |
Math IV: Multivariate Calculus |
pd |
Probability Distributions |
sm1 |
Statistical Modelling for EOR |
| Code | Course |
|---|---|
macro |
Macroeconomics for EOR |
m5ala · M5 |
Math V: Advanced Linear Algebra |
si |
Statistical Inference |
lms |
Linear Models in Statistics |
m6co · M6 |
Math VI: Convexity and Optimization |
sor |
Stochastic Operations Research |
dor |
Discrete Operations Research |
i2e |
Introduction to Econometrics |
li |
Life Insurance |
gt |
Game Theory |
ri |
Risk Insurance |
| Code | Course |
|---|---|
sm |
Stochastic Models |
An evolving learning workspace
Available now. Still growing.¶
The course hubs, named study sets, finite review sessions and read-only Teaching workbench are joined by the 0–100 mastery score, course diagnostics lists, worked exam problems for Math I, search in eight more languages, the Concept Galaxy, course achievements and account badges, monthly honours, the EOR Rating, live friendly duels and ghost races, study-connection applause and sharing, and Year 1 and Year 2 weekend quizzes following the current block's weekly teaching or revision period. Use the guide above to find each entry point and its sharing settings.
Keep a useful route forward
When something gets in the way¶
- Too many search results?
- Search inside the course, or add its code and a specific term in Finder.
- A formula is showing raw LaTeX?
- Refresh once. If it persists, report the page and formula that failed to render.
- Animations feel slow or distracting?
- Menus, panels, dialogs and folding sections open with a short motion. To turn every site animation off, open the sliders button left of the search box and untick Site animations; it applies at once and is remembered on this device. Lite turns animations off too, and Defaults turns them back on. If your device is set to reduce motion, the site never animates.
- Two devices show different progress?
- Check that both use the intended account, open My → Account → Sync & learning data, and inspect the result. If history needs recovery, follow the offered review and backup steps.
- Not sure what to study next?
- Choose one concept from Course diagnostics' Weak by evidence or Prerequisite gaps list, revisit its prerequisites and try an example. Rankings are not a study plan.
- Where is my public profile?
- Open My → Account → Public profile. Use Edit profile to update your account details; check My → Account → Privacy and Arena's public-record setting to control sharing.
- Cannot find an invitation or weekend activity?
- Open My → Rewards → Arena. Pending invitations stay in Duels. You can preview the weekend calendar before connecting an account; connect to join an official run. Scheduled competitions open at their displayed time. If My is unavailable, enable Account in the startup settings and follow the offered Reload action.
- Why is there no competition, or only one course this weekend?
- Teaching-week quizzes use only that week's taught topics in courses with available quizzes. A course without new lectures contributes no new topics. If the combined pool has fewer than ten eligible questions, no competition opens. Check the course scope on the weekend card, and that Course year shows your year. Only semester 1 of 2026–2027 is scheduled so far.
- Will the new weekend format reset my progress?
- No. Earlier scores, XP, EORbits, EOR Rating and honours stay with you. Events that have already started keep their rules, and historical events remain available for practice. The new format changes future competitions.
Help improve a page¶
Use an edit request for an error, unclear step, missing prerequisite, broken link or mismatched AI check. Include the page, the problem and a suggested correction or source.
Questions or suggestions?¶
Contact W. Zhu, aka Rock at w.zhu@rug.nl. For a technical issue, include the page and steps that led to it; keep login links and private learning records out of public reports.
Symbols: sum