fix(deep_reference): incorporate query relevance into recommended/confidence

The Stage 8 `recommended` selector and the evidence sort both rank by
FSRS-6 trust only, discarding the `combined_score` signal that the
upstream hybrid_search + cross-encoder reranker just computed. Confidence
is then derived from `recommended.trust + evidence_count`, neither of
which moves with the query — so any query against the same corpus
returns the same primary memory and the same confidence score.

Empirical reproduction (15 deep_reference probes against an 11-memory
corpus, 9 with a unique correct answer + 6 with no relevant memories):

  - Distinct primary memories returned : 1 / 15
  - Confidence values returned         : 1 distinct (0.82 for all)
  - Ground-truth accuracy on specific queries : 1 / 9 (11.1%)

The single hit is coincidental: the always-returned memory happened to
be the correct answer for one query. Random guessing across the 11-memory
corpus would be ~9% baseline, so the tool is performing at random.

Fix
---

Replace trust-only ranking at three sites with a 50/50 composite of
combined_score (query relevance) and FSRS-6 trust:

    let composite = |s: &ScoredMemory| s.combined_score as f64 * 0.5 + s.trust * 0.5;

Used in:
  - cross_reference.rs:573 — `recommended` max_by
  - cross_reference.rs:589 — `non_superseded` evidence sort_by
  - cross_reference.rs:622 — `base_confidence` formula

The 50/50 weighting is a design choice — see PR body for the knob to
tweak if a different blend is preferred. The pre-existing updated_at
tiebreaker is preserved.

Tests
-----

Two regression tests, both verified to FAIL on `main` and PASS with the
fix via negative control (temporarily set the composite weights to
1.0 trust + 0.0 relevance and confirmed both tests fail again):

  - test_recommended_uses_query_relevance_not_just_trust
      Two-memory corpus, ingested in order so the off-topic memory wins
      the trust tiebreaker. Query targets the on-topic memory. The fix
      ensures `recommended` is the on-topic one.

  - test_confidence_varies_with_query_relevance
      Single-memory corpus. Identical execute() calls with a relevant
      query and an irrelevant query. The fix ensures the relevant
      query produces higher confidence.

Full crate suite: 410 / 410 passing (was 408 + 2 new).

Out of scope
------------

While running the live MCP probes I observed two further inconsistencies
in `cross_reference.rs` that I cannot reproduce in cargo test (the
synthetic test environment with mock embeddings does not trigger the
required combined_score > 0.2 floor condition):

  - The `effective_sim` floor at line 551 fabricates contradictions
    between memories with no real topical overlap when one contains a
    CORRECTION_SIGNALS keyword.
  - The Stage 5 `contradictions` field (strict) and the Stage 7
    `pair_relations` feeding the reasoning text (loose, post-floor)
    disagree, producing responses where `reasoning` claims N
    contradictions while `contradictions` is empty and `status` is
    "resolved".

I have empirical data for both from live MCP usage but no reproducible
cargo test, so they are intentionally not addressed in this PR. Happy to
file them as a separate issue with the raw probe data if useful.
This commit is contained in:
NoahToKnow 2026-04-09 20:09:56 -06:00
parent 17038fccc4
commit 9c022a0f54

View file

@ -568,21 +568,33 @@ pub async fn execute(
// ====================================================================
// STAGE 8: Synthesis + Reasoning Chain Generation
// ====================================================================
// Find the recommended answer: highest trust, not superseded, most recent
let recommended = scored.iter()
// Composite score: half query relevance (combined_score from
// hybrid_search + reranker) and half FSRS-6 trust. Both signals belong
// in the recommended pick — relevance picks the right *topic*, trust
// picks the most reliable variant within that topic.
let composite = |s: &ScoredMemory| s.combined_score as f64 * 0.5 + s.trust * 0.5;
// Find the recommended answer: highest composite, not superseded, most recent
let recommended = scored
.iter()
.filter(|s| !superseded_ids.contains(&s.id))
.max_by(|a, b| {
// Primary: trust. Secondary: date.
a.trust.partial_cmp(&b.trust)
composite(a)
.partial_cmp(&composite(b))
.unwrap_or(std::cmp::Ordering::Equal)
.then_with(|| a.updated_at.cmp(&b.updated_at))
});
// Build evidence list (top memories by trust, not superseded)
let mut non_superseded: Vec<&ScoredMemory> = scored.iter()
// Build evidence list (top memories by composite, not superseded)
let mut non_superseded: Vec<&ScoredMemory> = scored
.iter()
.filter(|s| !superseded_ids.contains(&s.id))
.collect();
non_superseded.sort_by(|a, b| b.trust.partial_cmp(&a.trust).unwrap_or(std::cmp::Ordering::Equal));
non_superseded.sort_by(|a, b| {
composite(b)
.partial_cmp(&composite(a))
.unwrap_or(std::cmp::Ordering::Equal)
});
let evidence: Vec<Value> = non_superseded.iter()
.take(10)
.enumerate()
@ -605,8 +617,10 @@ pub async fn execute(
.collect();
evolution.truncate(15); // cap timeline length
// Confidence scoring
let base_confidence = recommended.map(|r| r.trust).unwrap_or(0.0);
// Confidence scoring: derived from the same composite as `recommended`,
// so confidence actually moves with query relevance instead of being a
// function of trust + corpus size alone.
let base_confidence = recommended.map(composite).unwrap_or(0.0);
let agreement_boost = (evidence.len() as f64 * 0.03).min(0.2);
let contradiction_penalty = contradictions.len() as f64 * 0.1;
let confidence = (base_confidence + agreement_boost - contradiction_penalty).clamp(0.0, 1.0);
@ -685,6 +699,129 @@ pub async fn execute(
#[cfg(test)]
mod tests {
use super::*;
use crate::cognitive::CognitiveEngine;
use std::sync::Arc;
use tempfile::TempDir;
use tokio::sync::Mutex;
use vestige_core::Storage;
fn test_cognitive() -> Arc<Mutex<CognitiveEngine>> {
Arc::new(Mutex::new(CognitiveEngine::new()))
}
async fn test_storage() -> (Arc<Storage>, TempDir) {
let dir = TempDir::new().unwrap();
let storage = Storage::new(Some(dir.path().join("test.db"))).unwrap();
(Arc::new(storage), dir)
}
async fn ingest_one(storage: &Arc<Storage>, content: &str, tags: &[&str]) -> String {
storage
.ingest(vestige_core::IngestInput {
content: content.to_string(),
node_type: "fact".to_string(),
source: None,
sentiment_score: 0.0,
sentiment_magnitude: 0.0,
tags: tags.iter().map(|s| s.to_string()).collect(),
valid_from: None,
valid_until: None,
})
.unwrap()
.id
}
// ========================================================================
// BUG A: `recommended` is picked by FSRS trust only, ignoring query relevance.
// ========================================================================
#[tokio::test]
async fn test_recommended_uses_query_relevance_not_just_trust() {
let (storage, _dir) = test_storage().await;
let id_a = ingest_one(
&storage,
"PostgreSQL connection pooling with pgbouncer transaction mode \
requires careful tuning of max_connections and pool_mode settings.",
&["postgres", "database"],
)
.await;
tokio::time::sleep(std::time::Duration::from_millis(10)).await;
let _id_b = ingest_one(
&storage,
"Making sourdough bread requires a mature starter, long bulk \
fermentation, and attention to dough hydration levels.",
&["baking", "bread"],
)
.await;
let args = serde_json::json!({
"query": "PostgreSQL connection pooling pgbouncer max_connections"
});
let result = execute(&storage, &test_cognitive(), Some(args))
.await
.expect("execute should succeed");
assert_eq!(
result["recommended"]["memory_id"].as_str(),
Some(id_a.as_str()),
"Expected recommended={} (matches query). Got {:?}. \
Root cause: lines 565-572 select `recommended` by trust only, \
discarding the combined_score signal from hybrid_search + reranker.",
id_a,
result["recommended"]["memory_id"]
);
}
// ========================================================================
// Confidence sanity: must vary with query relevance.
// ========================================================================
#[tokio::test]
async fn test_confidence_varies_with_query_relevance() {
let (storage, _dir) = test_storage().await;
ingest_one(
&storage,
"The Borrow Checker enforces Rust's ownership rules at compile time, \
preventing data races and use-after-free without a garbage collector.",
&["rust"],
)
.await;
let relevant = execute(
&storage,
&test_cognitive(),
Some(serde_json::json!({
"query": "Rust borrow checker ownership compile time"
})),
)
.await
.expect("execute should succeed");
let irrelevant = execute(
&storage,
&test_cognitive(),
Some(serde_json::json!({
"query": "18th century Dutch maritime trade routes"
})),
)
.await
.expect("execute should succeed");
let rel_conf = relevant["confidence"].as_f64().unwrap_or(0.0);
let irr_conf = irrelevant["confidence"].as_f64().unwrap_or(0.0);
assert!(
rel_conf > irr_conf,
"Confidence should be higher for a relevant query. Got \
relevant={}, irrelevant={}. Currently `confidence` derives from \
recommended.trust + evidence count (lines 602-605), both \
invariant under query changes.",
rel_conf,
irr_conf
);
}
#[test]
fn test_schema_structure() {