# Skill Verification Methodology > Lemma's skill verification methodology: what counts as evidence, how it is weighed, how reliability and integrity checks work and how disputes are corrected. Source: https://getlemma.io/methodology Skill verification on Lemma means checking each skill against recorded evidence instead of a claim. This methodology sets out what counts as evidence, how it is weighed, how reliability and integrity checks work, how partners are matched and how mistakes are corrected. Each part describes what Lemma does today. ## Three rules every score follows. ### Evidence, not claims You can list any skill you want to learn or teach. Listing it adds nothing to its score. Only recorded evidence does. ### Events, not edits Every piece of evidence is appended to a log. Scores are recomputed from that log by a versioned ruleset, so the same evidence always gives the same result. ### Explained by default Every score shows the drivers behind it. If a number cannot be traced back to the evidence that produced it, it does not appear. ## What counts as evidence of a skill? Five kinds of evidence count on Lemma: live sessions, adaptive assessments, peer confirmations, external proofs from GitHub, Figma or Vercel, and AI tutor practice. Each is recorded when it happens, by the system or by another person. None of it is typed in by you about yourself, and listing a skill adds nothing. ### Live sessions Learning and teaching sessions held in Lemma's video rooms. A session counts once both people have joined and it completes. Your partner's rating sets how much it adds, and teaching weighs more than learning. A session rated one star adds nothing. ### Adaptive assessments Timed assessments whose difficulty adapts to each answer, at two levels: a skill assessment and a longer certification assessment. Harder questions are worth more. Only your best result counts. Failed attempts carry a small, capped penalty, and retries have a cooldown. ### Peer confirmations Another member confirms you have the skill, usually after a session together. You cannot confirm your own skills. Only a few distinct people count toward a skill. ### External proofs A GitHub repository or commit, a Figma file or a Vercel deployment, linked through your own account so ownership is checked against that platform. Two per skill count. Remove one and the score is recomputed. ### AI tutor practice Drills passed in Lemma's AI tutor. They show steady practice between sessions. A low cap. Practice supports other evidence; it cannot replace it. ## How is skill evidence weighed? Evidence feeds SCI, a score from 0 to 100 for each skill. Four components add points, each with its own cap: practice up to 25, proof up to 40, reliability up to 20 and freshness up to 15. A fifth, integrity, can only subtract, so no single kind of evidence can carry a skill alone. Practice Sessions and tutor practice, weighted by partner ratings and by whether you taught or learned. Proof Assessments, peer confirmations and external proofs. The largest component, because it is the hardest to fake. Reliability Whether you show up. Completed sessions build it; no-shows and late cancellations take it away. Freshness How recent your latest evidence is. It fades over months when a skill goes unused. Integrity Zero for almost everyone. It only subtracts when the system detects a pattern built to inflate a score. Nobody edits a score by hand. When new evidence arrives, the skill is recomputed from its full evidence log. The ruleset that does it is versioned, so a past score can be replayed and checked. The SCI explainer covers what each component counts and how the caps work. [Read the full SCI explainer](https://getlemma.io/product/sci) ## Credibility depends on how you behave, too. A skill score says what you can do. Reliability and integrity checks say whether the record behind it holds up. ### Reliability is part of the record Completed sessions build reliability. Clean sessions add points up to a cap. No-shows and late cancellations in the last 30 days take points away; older ones no longer count. A long clean record earns a bonus that a single penalty removes. ### Patterns, not people, get flagged Integrity checks look for score inflation: most sessions with the same partner, or confirmations traded back and forth inside a small circle. Friends who study together a few times do not trip them; systematic repetition does. ### Assessments watch for help Questions have time limits and no going back, and recently seen questions are not served again. Each assessment carries an integrity score that drops with signals such as tab switching, pasting or leaving full screen. ### The same rules for everyone Subscription plans change what you can access, never how you are scored. A free member and a paid member with the same evidence get the same score. ## Matching ranks partners. It never touches scores. Matching suggests people to learn with or teach, based on the skills you have listed. Blocked people never appear, people you keep passing over appear less, and each suggestion comes with short reasons. ### Skill fit Whether you can teach each other, or only one way, and whether they teach the skill you are focused on now. This carries the most weight. ### Schedule How far apart your timezones are, so a session can happen at a reasonable hour for both of you. ### Language Whether you share a spoken language. No overlap lowers the rank but does not hide the person. ### Reliability Their session history. A record of turning up ranks higher; recent no-shows rank lower. ### What worked before The ranking learns from sessions that went well for people with similar skills and goals, and gives newer partners a fair chance to be seen. [How sessions work](https://getlemma.io/product/sessions) ## What happens when a session is recorded wrongly? Automatic completion is right most of the time. When it is not, either person can report the session, a member of the Lemma team reviews its history, and the fix is added to the record instead of rewriting it. Voided sessions are marked, not deleted, and scores are recomputed for both people. 1. ### Sessions complete from attendance A session completes on its own once both people have joined. If one person never joins, it is recorded as a no-show for them. 2. ### Either person can report a problem A no-show that was not one, a session that ended early, inappropriate behaviour. A report opens a support case, and a person reviews it with the session's history. 3. ### The decision is logged first A void refunds credits, reverses progress and stops the session counting. An upheld report leaves it standing. Either way, the correction is written to the log before it is applied. 4. ### Nothing is erased Voided records are marked, not deleted, and scores are recomputed for both people. Each session keeps the policy version it was booked under, so later rule changes do not rewrite it. ## Questions about the method. ### How do you verify someone's skills? Look for evidence the person did not produce about themselves: an adaptive assessment result, a live session reviewed by a practitioner, or work in a repository or design file they own. On Lemma each of these is recorded against one skill with its source and date, and SCI shows which evidence moved the score. ### Can I add a skill without any evidence? Yes. You can list skills you want to learn or teach, and they help matching find partners. A listed skill scores nothing until evidence is recorded against it. ### Why do failed assessments count against me? Each failed attempt carries a small penalty with a low cap. It stops people retrying until they pass by chance. Your best passing result is what counts toward Proof. ### Does a score drop if I stop practising a skill? Part of it does. Freshness falls as your latest evidence ages, so an unused skill slowly loses that component. The rest of your evidence stays on the record. ### Who decides a session dispute? A member of the Lemma team reviews each report with the session's history, then either voids the session or upholds it. Both outcomes are recorded as events, and the original record is kept. ## See the method at work. Join the early-access list to build a skill record of your own, or read how each part of the product applies these rules. - [The SCI explainerHow evidence becomes one score per skill](https://getlemma.io/product/sci) - [What a Passport containsThe signed record a reviewer receives](https://getlemma.io/product/passport) - [How assessments adaptDifficulty that follows every answer](https://getlemma.io/product/assessments) - [The verification APICheck a Passport from your own tools](https://getlemma.io/developers)