Multi Source Required For Load Bearing Claims

Multi-Source Required For Load-Bearing Claims

Project-level value-layer rule. Load-bearing claims drive downstream decisions that are expensive to reverse. The discipline of citing at least two independent sources before committing to such a claim is the cheapest available defense against the rationalization-trap failure mode (K2 §3.3, ConflictQA 2604.11209 §4): silently rationalizing one source's claim into a spec because no second source was consulted to disagree.

Provenance

• K2 design doc: docs/research/K2-knowledge-hygiene-from-papers.md §3.3 (Rationalization-trap as the sole value-layer rule in the knowledge-hygiene epic — silent single-source picks are the canonical shape this trap takes for load-bearing claims)
• Source paper: ConflictQA (2604.11209) §4 — quantifies how often LLMs silently rationalize when only one source is presented vs how rarely they rationalize when two contradicting sources are presented in parallel.
• Reused pipeline: plugins/knowledge-hygiene/skills/multi-source-research/SKILL.md (commit b28aa0f) — gather → conflict-detect → synthesize-with-provenance pipeline. This rule is the dev-standards-side pre-commit guidance that triggers that pipeline; the pipeline itself lives in knowledge-hygiene.
• Reused agent: plugins/knowledge-hygiene/agents/conflict-detector.md (same commit) — when two sources disagree, this agent classifies the conflict and recommends a resolution.
• Reused contract: brainstorming <PROVENANCE-CONTRACT> (commit ebd136a) — every cited source carries a provenance value from the 5-form vocabulary (file:path:line | memory:id | git:sha | web:url | literal "guess").

The Value-Layer Rule

A load-bearing claim MUST be supported by at least two independent sources, OR the gap MUST be surfaced visibly to the user with an explicit "single-source — please confirm" note. Silent single-source picks on load-bearing claims are forbidden.

This is the third must in the dev-standards plugin (alongside verification-before-completion and no-compression-on-skill-frontmatter). The must is on visibility, not on resolution — the rule does not require that all conflicts be resolved before commit, only that the gap be surfaced visibly. The user can override.

What "Load-Bearing" Means Concretely

A claim is load-bearing when, if it turns out to be wrong, the cost of correction extends beyond a local edit. Three named categories cover most cases:

Category 1 — Architecture decisions

A claim is load-bearing if it constrains the shape of the system: which storage backend, which session model, which serialization format, which message-queue topology, which authn/authz primitive, which inter-service protocol, which build/deploy substrate. Concrete examples:

• "We use Postgres because we need strong consistency on writes." (Single-source: a blog post claiming Postgres beats MySQL on consistency is not enough. Need: official docs + a benchmark or in-repo precedent.)
• "We chose JWT for session because it scales horizontally without server state." (Single-source: a Stack Overflow answer is not enough. Need: official spec + a security-reviewed pattern.)
• "We use Tailwind because the team prefers utility-first CSS." (Single-source: a team preference is not enough as a load-bearing assertion. The claim itself is fine; the load-bearing form would be "Tailwind scales to N components without selector-collision issues" which needs evidence beyond preference.)

Category 2 — Security claims

A claim is load-bearing if it sets the security baseline for a class of operations: hashing primitive selection, key-derivation function selection, TLS version requirements, CSRF/CORS posture, input-validation rules at trust boundaries, rate-limit thresholds, audit-log requirements. Concrete examples:

• "bcrypt with cost factor 12 is sufficient for our threat model." (Single-source: the bcrypt manpage is not enough. Need: OWASP guidance + a recent benchmark for the deployment hardware.)
• "We rate-limit at 100 req/min because that matches user behavior." (Single-source: a single product-analytics query is not enough. Need: analytics + a security review of the bypass surface.)
• "API keys in headers are sufficient — we don't need OAuth here." (Single-source: a blog post is not enough. Need: official protocol docs + a documented threat model that explicitly excludes the OAuth-relevant attacks.)

Category 3 — Performance claims

A claim is load-bearing if downstream consumers will plan capacity, scaling, or UX timing around it: algorithmic complexity assertions, latency targets, throughput baselines, memory budgets, cache hit-rate assumptions. Concrete examples:

• "This lookup is O(log n) so it scales fine to 10M entries." (Single-source: reading the function signature is not enough — the implementation behind the signature is the load-bearing fact. Need: signature + implementation read + a benchmark at expected scale.)
• "Redis cache hit rate will be ≥90% so the DB load stays bounded." (Single-source: a vendor blog is not enough. Need: vendor data + an in-repo or representative-workload measurement.)
• "Page load under 2s on 3G — verified by our staging measurement." (Single-source: one staging run is not enough — need at least two independent measurements at different times or different network profiles to rule out a transient.)

What "Independent Sources" Means

Two sources are independent if they do not derive from the same upstream — copying the same Stack Overflow answer twice is one source, not two. Concrete independence tests:

When in doubt, ask: "if Source A turned out to be wrong, would Source B also be wrong by the same mistake?" If yes, they are not independent.

The Escape Valve — When One Source Is Enough

The rule has an explicit escape valve, consistent with the project's soft-guidance posture for everything except the visibility must. One source is enough when both of the following hold:

1. The source is the artifact itself. A function's signature read from its own source file is authoritative for "what is this function's signature" because the source file is the function's signature. There is no second source possible. Same for: file contents read directly, environment variable values read at runtime, config values read from the canonical config file.
2. The claim is scoped to the artifact. The claim "function foo returns Result<T, E>" is single-source-ok if read from the function's own definition. The claim "function foo is performant under load" is not single-source-ok even if the function source is read, because performance is not contained in the signature.

When the escape valve applies, the single source still carries provenance: the citation in the spec / decision / review uses the brainstorming <PROVENANCE-CONTRACT> file:path:line form to make the artifact-source explicit.

How To Surface The Gap When You Don't Have Two Sources

When a load-bearing claim must ship and only one source is available, the rule requires visible gap surfacing, not silent shipping. The minimum-viable surface:

**Single-source claim — please confirm.** The assertion "<claim text>" is supported only by <source A: provenance>. I was unable to find an independent corroborating source within this session's research budget. Three escalation options:

1. **Confirm-as-is** — accept the single-source claim with the visible note kept in the spec / commit / review. The single-source flag stays in the document for future readers.
2. **Defer the claim** — strip the claim from this commit; open a follow-up dart-task to research the second source.
3. **Reframe as hypothesis** — keep the claim but label it explicitly as `hypothesis (single-source)` so downstream consumers know it is not a settled decision.

The agent / reviewer / writer picks one of the three and proceeds. The point is the explicit choice; the silent skip is what the rule forbids.

Interaction With The Knowledge-Hygiene Pipeline

This rule is the dev-standards trigger for the multi-source-research pipeline that lives in the knowledge-hygiene plugin. The handoff:

1. Writer / reviewer identifies a load-bearing claim per the three categories above.
2. Writer invokes knowledge-hygiene:multi-source-research skill with the claim and the load-bearing-ness signal.
3. The skill's pipeline (gather → conflict-detect → synthesize) returns the corroborated claim with provenance per source, OR an "insufficient sources" verdict triggering the gap-surface escape valve above.
4. If the pipeline detects a conflict between two sources, knowledge-hygiene:conflict-detector agent classifies the conflict (one of 7 named types) and recommends one of 4 resolutions (prefer-recent / prefer-authoritative / escalate-to-user / not-applicable).
5. The recommendation is surfaced visibly in the spec / commit / review per the K2 §3.3 rationalization-trap rule — not silently absorbed.

This rule is the producer-side contract; the knowledge-hygiene plugin is the consumer-side mechanism. Together they implement the K2 multi-source-with-conflict-surfacing pattern at the project level.

What This Rule Does NOT Cover

• Non-load-bearing claims. Typo fixes, comment rewording, docstring updates, log-message edits, formatting changes — these do not need multi-source corroboration. The rule scopes only to claims with downstream cascade.
• Exploratory hypotheses. A brainstorm bullet labeled provenance: guess per the <PROVENANCE-CONTRACT> is already self-flagged as unverified; no multi-source requirement applies until the bullet is promoted to a decision.
• Implementation details below the architecture line. "I named this variable foo because the surrounding code uses foo-prefix" is a local convention, not a load-bearing claim.
• Hard merge gates. The rule is enforced by reviewer attention and skill-using subagent discipline, not by a pre-commit hook or merge-blocker. Visible gap surfacing is the gate; the resolution is human-overridable.

Self-Application

This SKILL.md's own load-bearing claims:

• "Silent single-source picks are the canonical rationalization-trap shape for load-bearing claims" — cited from K2 §3.3 + ConflictQA 2604.11209 §4 (two sources, paper + synthesis doc, independent).
• "The multi-source-research pipeline lives in the knowledge-hygiene plugin" — cited from plugins/knowledge-hygiene/skills/multi-source-research/SKILL.md + commit b28aa0f (in-repo + git history, independent corroborations).
• "bcrypt example needs OWASP + benchmark" — cited as illustrative, not asserted as a load-bearing decision in this skill itself; the example is meta-evidence for the rule, not a claim the rule makes about bcrypt.

The rule applies its own discipline: every load-bearing claim above is double-cited; the illustrative examples carry their evidence-type label so the reader can distinguish "this is the rule" from "this is what the rule looks like applied."

Anti-Patterns

Relationship To Other Skills

• knowledge-hygiene:multi-source-research/SKILL.md — the consumer pipeline that this rule triggers. Producer-side rule (here) → consumer-side mechanism (there).
• knowledge-hygiene:rationalization-trap-check/SKILL.md — post-hoc audit for the failure mode this rule prevents. Together they form prevention (this skill) + detection (rationalization-trap-check).
• knowledge-hygiene:conflict-detector agent — invoked inside the pipeline when two sources disagree.
• brainstorming:brainstorming <PROVENANCE-CONTRACT> — provides the 5-form provenance vocabulary every cited source uses. This rule reuses, does not redefine.
• no-compression-on-skill-frontmatter (sibling skill) — protects skill-metadata integrity; this rule protects load-bearing-claim integrity. Both are value-layer must rules in this plugin.
• memories-require-timestamp-and-source (sibling skill) — adds temporal grounding to the memory layer so the conflict-detector can prefer recent over stale when two memories disagree. Complementary discipline.
• verification-before-completion — the other long-standing must in this plugin. That rule covers evidence-before-completion-claims; this rule covers source-multiplicity-before-load-bearing-claims. Distinct scopes, same family.