Evidaxis

Methodology · v1 (frozen)

How Evidaxis measures momentum

Evidaxis measures the rate of change of a system’s public signals, normalized against its peers, and recognizes a system as rising only when independent signals agree. This page is the complete, versioned definition. It is frozen: a published score is never silently recomputed.

Principles

  • Slope, not size. Every axis is the log-slope of a trend — momentum, not magnitude. Stars, totals, and raw counts are never scored.
  • Within cohort. A system is compared only to peers in its sub-niche, so “rising” is relative, and a small fast-mover can outrank a large incumbent.
  • Convergence. One signal can be gamed or noisy. Recognition requires two independent axes rising at once.
  • Positive-only. Evidaxis publishes who is rising. There is no “worst” list and no negative label.
  • Systems, not people. The measured unit is always a system. A builder may appear as an honorary, claimable face, but individuals are never scored.

Axis 1 — Development velocity

The least-squares slope of log(1 + weekly commits) over the trailing 26 weeks. A fast, leading signal of where active work is accelerating.

velocity = slope( log(1 + commits_w) ),  w ∈ last 26 weeks

Axis 2 — Citation momentum

The slope of log(1 + citations/year) to the system’s canonical paper (OpenAlex), measuring recent acceleration of scholarly impact — a slow, confirming signal. To make it a momentum rather than an all-time-growth measure we drop the partial current year and, when four or more completed years exist, the earliest (birth) year — whose anomalously low count would otherwise inflate the slope of a cooling paper. At least three completed years are required. 

citation = slope( log(1 + cites_y) ),  y ∈ completed years, birth year dropped

Normalization

Within each cohort, raw axis slopes are converted to a robust z-score using the median and median absolute deviation (resistant to a single outlier), then residualized against a size proxy (log stars for velocity, log total citations for citations) so that scale is removed and only relative momentum remains. 

z = clamp( (slope − median) / (1.4826 · MAD), ±3 ) ;  z ← residual on log(size)

The convergence gate

A system is Rising when at least two axes are present and at least two are rising. An axis is “rising” when its raw slope is positive and its within-cohort z ≥ 0. Development velocity additionally requires a minimum of 5 average weekly commits — a dormant repository is never rising on a sliver of noise.

Rising  ⟺  |axes_present| ≥ 2  ∧  |axes_rising| ≥ 2
axis rising  ⟺  slope > 0  ∧  z ≥ 0   (velocity also: commits/wk ≥ 5)

Watch = exactly one axis rising. Tracked = measured on two axes, none rising. Single-axis = only one axis available (e.g. no paper exists). Calibration = a mature incumbent included to anchor a cohort; measured but never badge-eligible.

Momentum score

A 0–100 readout for ranking within a cohort: the mean of an entity’s present-axis z-scores, mapped linearly. It is a convenience view; the gate, not the score, decides recognition.

momentum = clamp( 50 + 12.5 · mean(z_present), 0, 100 )

Versioning & honesty

Every record carries its methodology_version and snapshot_id. Methodology is frozen, not recomputed: a correction is a new version on a new row, never an edit to an old one — so a citation of “momentum 60.4, 2026-w26” stays meaningful forever. The full data is byte-reproducible from each snapshot’s manifest.

Known limitations (stated, not hidden)

  • Citation lag. OpenAlex citations are annual and trail real activity by years, so a genuinely new (2024–25) system cannot yet show citation momentum. The convergence signal sharpens as the weekly time-series accumulates — this is why Evidaxis is a long-running observatory, not a one-shot ranking.
  • Coverage is partial. See the coverage atlas for exactly what is and is not measured. Silence means “not yet measured,” never “low quality.”
  • Source undercount. OpenAlex undercounts some papers versus other indexes; we use only relative slopes, never absolute magnitudes, to stay robust to this.

References & primary sources

Every score traces to a public source. The axes and transforms above are computed from:

  • Development velocity — weekly commit counts from the GitHub REST statistics API (/repos/{owner}/{repo}/stats/commit_activity).
  • Citation momentum — yearly citation counts from OpenAlex Works (counts_by_year), an open scientometric index.
  • Robust normalization — the median and median absolute deviation (MAD); the scale factor 1.4826 makes the MAD a consistent estimator of the standard deviation for normal data (Rousseeuw & Croux, 1993, JASA).
  • License — all data is released under the CC0 1.0 Public Domain Dedication.
  • Vocabulary — see the Evidaxis glossary for definitions of every term used here.

This is the frozen v1 definition. The current active version is always at /methodology/current. Methodology prose is licensed CC-BY-4.0.