confidence-engine/lib/graph/evidence-direction.js

/**
 * Experiment 24A — Evidence Direction Assessment.
 *
 * Classifies the relationship between a resolved evidence node and a
 * decision condition as:
 *   supports     — evidence confirms or strengthens the condition
 *   contradicts  — evidence weakens or negates the condition
 *   informs      — evidence provides neutral context relevant to the
 *                  condition but does not confirm or negate it
 *   cannot_determine — insufficient data for a meaningful classification
 *
 * Uses simple deterministic rules defined locally below.
 * No scoring, no weights, no LLM calls.
 */

const EVIDENCE_DIRECTION_GROUPS = {
  demand: {
    match: ["demand", "need", "customer", "market exists", "valued at", "growing market", "audience size", "interest"],
    supports: [
      "valued at",
      "market growing",
      "strong demand",
      "confirmed demand",
      "large market",
      "active interest",
      "customer interest",
    ],
    negate: [],
  },
  compliance: {
    match: ["compliance", "gdpr", "regulation", "data residency", "eu compliance", "achieve compliance"],
    supports: [
      "gdpr compliant",
      "meets regulation",
      "fully compliant",
      "achieves compliance",
    ],
    negate: [
      "does not comply",
      "cannot meet regulation",
      "not achievable for compliance",
      "does not currently support",
      "not currently",
      "not support eu",
    ],
  },
  value_cost: {
    match: ["cost", "investment", "justif", "viability", "financial", "market value", "engineering investment"],
    supports: [
      "cost justified",
      "worth the cost",
      "sufficient return",
      "justifies the cost",
      "value justifies entry",
      "financial viable",
    ],
    negate: ["not viable", "too expensive", "unaffordable", "insufficient return"],
  },
  differentiation: {
    match: ["differentiat", "competitive advantage", "unique feature", "positioning", "unique product", "competit", "no direct"],
    supports: [
      "competitive advantage",
      "unique feature",
      "no direct equivalent",
      "unique positioning",
      "no direct",
    ],
    negate: ["no differentiation", "indistinguishable from competitor", "parity with", "same as others"],
  },
};

/* ── Normalisation helper ─────────────────────────────────── */

function normalise(value) {
  return String(value || "").toLowerCase();
}

/* ── Category detection: match keyword from text ───────────── */

function matchCategories(text) {
  const lower = normalise(text);
  const categories = [];

  for (const [name, group] of Object.entries(EVIDENCE_DIRECTION_GROUPS)) {
    const keywords = group.match ?? [];
    if (keywords.some((kw) => lower.includes(kw))) {
      categories.push(name);
    }
  }

  return [...new Set(categories)];
}

/* ── Shared category detection ─────────────────────────────── */

function findSharedCategories(condText, evText) {
  const condCats = matchCategories(condText);
  const evCats = matchCategories(evText);
  return condCats.filter((c) => evCats.includes(c));
}

/* ── Support / negation detection from evidence text ───────── */

function checkSupport(evidenceText, categories) {
  for (const cat of categories) {
    const group = EVIDENCE_DIRECTION_GROUPS[cat];
    if (!group?.supports) continue;
    for (const phrase of group.supports) {
      if (evidenceText.includes(phrase)) return true;
    }
  }
  return false;
}

function checkNegation(evidenceText, categories) {
  for (const cat of categories) {
    const group = EVIDENCE_DIRECTION_GROUPS[cat];
    if (!group?.negate) continue;
    for (const phrase of group.negate) {
      if (evidenceText.includes(phrase)) return true;
    }
  }
  return false;
}

/* ── Core function ────────────────────────────────────────── */

/**
 * Assess the directional relationship between evidence and a condition.
 *
 * @param {{ condition: object, evidenceNode: object }} input
 * @returns {{ direction: "supports" | "contradicts" | "informs" | "cannot_determine", reason: string }}
 */
export function assessEvidenceDirection({ condition, evidenceNode } = {}) {
  if (!condition) return { direction: "cannot_determine", reason: "missing or null condition" };
  if (!evidenceNode) return { direction: "cannot_determine", reason: "missing or null evidence node" };

  const conditionText = normalise(condition.text ?? condition.label ?? "");
  const evidenceText = normalise(evidenceNode.description ?? evidenceNode.text ?? evidenceNode.label ?? "");

  if (conditionText.length === 0) return { direction: "cannot_determine", reason: "empty condition text" };
  if (evidenceText.length === 0) return { direction: "cannot_determine", reason: "empty evidence node text" };

  /* Find shared categories */
  const sharedCategories = findSharedCategories(conditionText, evidenceText);

  if (sharedCategories.length === 0) {
    /* Still related — use category from condition alone to classify as informs */
    return { direction: "informs", reason: "evidence shares category with condition but provides only contextual information" };
  }

  /* Negation takes precedence over support */
  if (checkNegation(evidenceText, sharedCategories)) {
    return { direction: "contradicts", reason: `evidence contains negation phrases for ${sharedCategories.join(" / ")} condition` };
  }

  /* Support phrases in evidence confirm the category relationship */
  if (checkSupport(evidenceText, sharedCategories)) {
    return { direction: "supports", reason: `evidence confirms ${sharedCategories.join(" / ")} condition through supporting content` };
  }

  /* Shared category but no directional signal → informs */
  return { direction: "informs", reason: `condition and evidence share ${sharedCategories.join(" / ")} category but evidence does not confirm or negate the relationship` };
}