Anonymous usage statistics

What Chemistry Help counts

When aggregate statistics are enabled, Chemistry Help counts page views and broad interactions such as starting a game, opening a hint, checking an answer or completing a tool. For generated practice it can also count the question family or skill being used and a broad outcome such as correct first time, retry, clue or worked answer. While you are signed out, this browser can also keep an approximate practice-depth count so Chemistry Help can measure how many browser-days and browsers reach broad daily or lifetime milestones such as 25, 100 or 400 practice units before any future anonymous-use limit is considered. It may also count a broad device-size category, how far a page was scrolled, a broad visible-time band, whether a visit arrived directly or from search, whether a search landing became engaged or started practice on that page, which Chemistry Help page was viewed next, aggregate teacher/student sharing actions or arrivals through a Chemistry Help share link, and broad app-install actions such as an install invitation being shown, clicked, dismissed or completed. For the private admin graphs, the browser can also count itself at most once per local clock hour and once per browser-day when it first becomes engaged or starts practice; only the weekday/hour or broad stage is sent, not a timezone or visitor identifier. When you use the site search, the final meaningful search can be counted when you press Enter, choose a result or close search so failed searches and missing vocabulary can be improved. On Chem Racer, the same anonymous system can count visits, race starts, finishes, restarts or exits, broad race settings, broad device type, correct/incorrect/missed gate totals and a broad session-duration band. Chem Racer sends no public racing alias, My Chemistry user ID, exact steering trace or answer-by-answer personal history to anonymous analytics.

The same statistics choice also controls the small live visitor count shown only to the site administrator. While a page is visible, this browser can send a heartbeat about every 30 seconds using a random temporary presence token. The token is shared between tabs so one browser is counted once, rotates after no more than six hours, and is used only to count browsers active during roughly the previous 90 seconds. The heartbeat says only whether this browser currently appears signed in to My Chemistry or is a guest.

What these statistics do not store

• No long-lived analytics cookie or visitor identifier is used. The live count is the narrow exception: it sends a random temporary presence token, and the server stores only a SHA-256 hash of that token with its last heartbeat time and My Chemistry/guest state. The active record falls out of the count after about 90 seconds; no page history is attached to it. Separate browser-count dates/periods, the last locally counted hour, broad browser-day stage flags and the local practice counter stay in this browser, with the server receiving only aggregate browser-count events, weekday/hour buckets, broad stage events, practice milestones and broad practice-depth buckets.
• No name, email address or typed chemistry answer is stored in anonymous analytics. Site-search terms are the exception: they are normalised and kept only as aggregate counts, with obvious email, URL and phone-like input discarded.
• No IP address is stored. The request IP can be checked transiently against a small administrator-exclusion list so the site owner's own browsing does not inflate the anonymous analytics or live count, then it is discarded. No full user-agent string, full referring URL or individual session replay is kept.
• No cross-site tracking, advertising profile or data sale.

Events are added to daily totals as they happen. The browser-counting dates/periods and practice-depth counter stay in this browser. The server receives aggregate day/week/month browser counts and, for signed-out practice, milestone events such as “reached 100 units today”. The separate live-presence store contains only currently active temporary token hashes; it does not record which pages a token visited. If a My Chemistry save-progress prompt is shown or clicked, or a first sign-in returns through Chemistry Help, the server may receive only a broad practice-depth bucket such as 10–24 or 100–199. Daily counts can distinguish a browser first seen on the site from one seen on an earlier day, but the server is not given an identifier that links those counts together. Page-to-page movement and search terms are also stored only as aggregate counts. The dashboard contains group totals and no individual browsing history.

Live class responses

When your teacher starts a live class, you can join with the code on the board. I don't ask for your name, email, school or My Chemistry account. Your browser makes a random temporary token so you can change your answer or refresh the page without joining twice. The server keeps a hash of that token, its last check-in time and your latest answer and Ready, Not sure or I don't get it selection for the current question. Multiple-choice answers use an option letter; numerical answers keep the number you entered, including trailing zeros.

Your teacher sees anonymous totals and answer frequencies. On supported questions, they can also see how many answers match the marking rule and any recognised error patterns. I don't link the participation token to My Chemistry, and live class answers never change your individual scores, review queue or specification tracker. This works the same way when you happen to be signed in to My Chemistry. Pupil joining and participation pages do not send ordinary site analytics or live visitor heartbeats.

Each class also needs a public join code, private teacher-token hashes, its activity identifier, current question revision, response choices and control settings. For supported questions, the private class record also holds the current marking rule and error-pattern metadata. These are not sent to pupil devices. Asking the same question again keeps an aggregate first-round snapshot and clears individual first-round answers. Starters and exit tickets keep up to five aggregate question summaries, with no pupil-by-pupil answer trail. Finishing a sequence clears its final individual answers too. All these summaries and marking data expire with the class. Choosing End class deletes the class record and its responses. A class stops working after ten minutes without a teacher check-in, or after four hours in total. Expired records are removed by the cleanup task or the next site request that runs housekeeping; pupil check-ins cannot keep an abandoned class open.

If your teacher sends a practice link, you choose whether to open it. The link contains only the activity and course settings; no class code, participation token or classroom answers follow you. Ordinary Chemistry Help and My Chemistry progress recording applies on the practice page.

Teacher controls use a private link. Anyone with that link can control the class, so keep it off the projected screen and don't give it to students. The private token is sent in an API request header, not in a public joining link or ordinary URL query. Closing the pupil tab normally clears its browser-session token; choosing Leave class removes that participant's server record immediately.

Live classes use temporary operational storage. Where the teacher allows statistics, I also keep daily group totals showing whether classes started, devices joined, responses arrived, a second round received answers, starters or exit tickets finished, and a practice link was opened. Final totals use broad participant, question-count and duration bands. They distinguish a teacher ending a class from expiry after participation or no participation. Fixed server-error categories help me spot faults. These statistics contain no class codes, tokens, account identifiers, answer text or diagnostic wording. The teacher’s statistics choice and administrator-IP exclusion apply to the whole class.

The teacher’s browser can remember the last day it started a measured class. It sends only a broad category such as first use, same-day repeat or returned within 2–7 days. That date stays in the browser; no persistent browser identifier goes to the statistics store. Turning anonymous statistics off clears that return date. A separate local preference remembers whether you have seen the live-class instructions.

If you start a measured class while signed in to My Chemistry, My Chemistry can count classroom starts and active days against your existing account. This helps me tell whether signed-in classroom users return on another computer. Chemistry Help does not receive your account identifier, name or email for this. The account record contains no class code, pupil token, pupil answer or classroom result, and it never changes learner progress. See My Chemistry’s classroom-usage information.

The class store has no raw IP addresses, user-agent strings, names or account identifiers. To limit abuse, a separate short-lived rate-limit store uses keyed hashes of network addresses, with buckets lasting at most an hour. Hosting access logs and backups are separate from these application stores; the live class directory should be excluded from backups.

Student FAQ questions and suggestions

If you use the Student FAQ form, your question or suggestion is sent to the private My Chemistry admin system. The form does not ask for your name, email address or school, and asks you not to include personal information.

If you are signed in, the question can be linked to your My Chemistry account so you can find the answer again. If you are signed out, My Chemistry gives the question a random reference code and can also recognise it during the same Members browser session. Your original wording is not published automatically. If a question would help other students, I can write a cleaned public version of the question and answer for the FAQ.

Quick suggestions

The homepage suggestion box sends the words you type plus the page title and route to the private My Chemistry admin system. It does not ask for your name, email address or school. Please do not include personal information in the message.

For most visitors, quick suggestions are stored without an account identity. A small group of signed-in users may see a notice that the suggestion can be linked to their My Chemistry account; that notice also includes a Send anonymously choice. If the notice is not shown, the suggestion is stored without an account identity.

Teacher feedback and wishlist

If you use the teacher feedback form, Chemistry Help sends the information you choose to provide to the private My Chemistry admin system so it can be reviewed. This can include the request type, board, year, topic, your message, whether you are interested in homework tools and an optional reply email. Please do not include student names or other pupil personal information.

Teacher feedback is used to correct problems and decide what to improve or build next. A reply email is used only if a response is useful; it is not added to a marketing list. See the My Chemistry privacy notice for the account service's wider data-protection information.

Reporting an issue

Interactive tools include a small “Report an issue” control. Opening it does not submit a report. If you send a report, it includes the reason you chose plus enough context to investigate the current activity, such as the tool, current question or generated state, site version, page and basic browser/display information. If an answer or worked solution is visible, that may be included so the problem can be reproduced. A written note is optional unless you choose “Something else”. If you open the reporting panel for a few seconds but leave without sending, we may keep a low-priority signal that the activity prompted you to consider reporting it; this is stored separately from submitted reports.

These reports are separate from the anonymous aggregate statistics above. If you are signed in to My Chemistry, a report may be associated with that account; otherwise it is treated as a guest report. Reports are used only to check and improve the learning content and site operation.

Saved My Chemistry results

If you are already signed in to My Chemistry, supported tools can save a completed result. The result is sent directly to members.chemistryhelp.co.uk and may include the activity mode, score, time, items missed and broad question-family or skill labels needed for progress and review. Checking your sign-in state may create or use a random Members session cookie, which is sent only to the Members subdomain. Chemistry Help does not receive your members sign-in details.

Your browser can remember your exam board, course, topic and the last public activity you started, so you can find your way back. These hints are used for up to 21 days and can be removed by clearing this site's browser storage. Links between Chemistry Help, My Chemistry, Chem Racer and the models can carry the course, skill and public page to return to. This navigation information contains no account identity or marks. The homepage can offer a link to recent public practice. That link opens the tool again. “Continue your quiz” opens an unfinished quiz held in your signed-in My Chemistry account.

If you are not signed in, a result or personal best may be kept in this browser so that you can choose to save it later. Maths Skills tools also keep recent skill results for weak-spot practice and may remember your calculator-key choice. These values stay in your browser. Each maths tool has a control to clear its local practice history. When anonymous statistics are enabled, the separate local practice-depth counter described above can also be used to record only the broad depth bucket at which a save-progress prompt is viewed or clicked and, when sign-in returns through Chemistry Help, the broad bucket before that browser's first observed My Chemistry sign-in. The browser can also remember whether an install invitation has been shown or dismissed so Chemistry Help does not keep asking. That install preference stays on this device. Clearing this site's browser storage removes these local values.

Your choice

You can turn off anonymous usage events for this browser at any time. The off choice is also written as a Chemistry Help domain preference so supported subdomains such as Chem Racer can respect it. This also stops live-presence heartbeats, removes the temporary presence token from this browser, and clears the browser-counting dates/periods, local hour/stage counters and anonymous practice-depth analytics counter described above. Any active server presence entry then disappears immediately when the cleanup request succeeds, or automatically after about 90 seconds. It does not delete a separately queued My Chemistry result or local personal best.

Contact

Use the feedback form if you have a question or objection.

Signed-in tutee reviews

For authenticated current tutees in learner context, selected study-page visits, practice actions and short intervals of visible use are saved for Dr Smith’s lesson reviews. Estimated active time pauses when the page is hidden or after five minutes without interaction. Concurrent tabs count once. This tracker does not collect entered answers, chat text or time spent on external sites. Raw actions and Virtual Chemistry status observations are kept for up to 400 days; saved reports and tutoring history remain with the account until deletion. Dr Smith chooses when to publish a private review to the student. See My Chemistry’s privacy notice for account-data requests.