How Lemma verifies skills.

The problem

Most skill verification systems rely on self-reporting or one-time assessments. LinkedIn endorsements cost nothing to give and mean nothing to receive. Certificates prove you passed a test on one day, not that you retained the knowledge. Resumes are unverified by design.

Our philosophy

Skill credibility must be earned through repeated, observable behavior over time. A single data point is noise. A pattern of consistent evidence is signal. We measure the pattern.

Trust is not a feature. It is an emergent property of honest measurement applied consistently.

The approach

Every interaction on Lemma generates an immutable evidence event. Sessions, peer endorsements, assessment results, external proofs, and portfolio artifacts are each weighted and combined into a single composite score: the Skill Credibility Index.

SCI is event-sourced. That means we can replay every score from raw events, detect drift, and guarantee that no score was arbitrarily assigned. The formula is versioned and deterministic. Same inputs, same output, every time.

Evidence over opinion

We track five distinct evidence types, each capturing a different dimension of skill credibility. Sessions prove you can teach or apply a skill live. Endorsements carry weight proportional to the endorser's own credibility. External proofs anchor your skill claim to artifacts outside Lemma.

The result

A portable, verifiable Skill Passport that an employer can check in seconds. Not a badge wall. Not a points gamification system. A transparent record of demonstrated competence, scored by an algorithm you can read, built on evidence you can inspect.