| --- |
| license: apache-2.0 |
| task_categories: |
| - feature-extraction |
| - question-answering |
| tags: |
| - structure-mapping |
| - analogical-retrieval |
| - zero-lexical-overlap |
| - predicate-lattice |
| - retrieval-benchmark |
| - rare-events |
| - reasoning |
| - sma |
| pretty_name: Structure Synthesis Benchmark (SSB) |
| --- |
| |
| # Structure Synthesis Benchmark (SSB) |
|
|
| ## Dataset summary |
|
|
| The **Structure Synthesis Benchmark (SSB)** is a zero-lexical-overlap structural |
| retrieval benchmark designed to test whether a retrieval system matches on |
| **relational structure alone**, with no surface vocabulary shared between the |
| query and the target analog. |
|
|
| SSB is part of the SMA-1 evaluation suite (paper: *"Structure-Mapping Agentic |
| Memory"*, Ayaz Khan, 2026, under review at *Nature Machine Intelligence*). |
|
|
| **Headline result (from `reports/confirmatory/ssb_summary.csv`, seeds 41 and |
| 43, n = 100 per seed):** |
| |
| | Method | Forced-choice r@1 | Library r@1 | |
| |---|---|---| |
| | SMA (structure-mapping) | **1.000** (SD 0.000) | **0.895** (SD 0.007) | |
| | BM25 | 0.000 (SD 0.000) | 0.000 (SD 0.000) | |
| | TF-IDF Dense | 0.000 (SD 0.000) | 0.000 (SD 0.000) | |
| |
| Cliff's δ = 0.895, p_Holm = 0.0004 (paired bootstrap, 10 000 resamples). |
| |
| --- |
| |
| ## Dataset construction |
| |
| ### Core principle: disjoint per-triple vocabularies |
| |
| Each benchmark triple (base, target, distractor) uses **independently sampled |
| random functor names** so that the query and its true analog share **zero surface |
| vocabulary**. The only bridge is a **declared predicate lattice**: the |
| query functor and the analog functor are mapped to the same abstract concept |
| in the lattice, and retrieval requires ascending at most δ = 2 hops |
| (penalised by ρ^distance = 0.95^hops). |
|
|
| This construction directly operationalises Gentner's systematicity principle: |
| a system that matches on surface co-occurrence will score every candidate |
| equally (zero lexical signal); only a system that ascends the predicate lattice |
| to find structural correspondences will score the true analog higher. |
|
|
| ### Previous (broken) construction — what we fixed |
|
|
| Prior versions used a `far_` / `near_` prefix naming trick: the same functor |
| vocabulary was reused across triples, and the "far" analog was simply the |
| renamed version. This was circular — the benchmark unknowingly told the system |
| which triple was the analog. The current generator eliminates this entirely: |
|
|
| - Each triple receives a fresh randomly-sampled vocabulary (UUID-derived functor |
| names with no shared substrings). |
| - Distractors are star-rewired (provably non-isomorphic to chain-structured |
| analogs for width ≥ 3) so a correct matcher cannot accidentally score a |
| distractor 1.0. |
| - The MAC screening stage uses the ancestor-closure feature vector (blueprint |
| §2.7) so lattice-bridged vocabularies intersect at screening; the Lemma-2 |
| bound remains admissible with ancestor features. |
|
|
| ### Generation parameters (frozen at prereg-v1) |
|
|
| | Parameter | Value | |
| |---|---| |
| | Lattice ascension depth δ | 2 hops | |
| | Ascension penalty ρ | 0.95 per hop | |
| | Structural width | ≥ 3 (chain structure) | |
| | Vocabulary collision probability | < 10⁻⁶ (UUID-space) | |
| | Seeds used in confirmatory runs | 41, 43 (n = 100 each) | |
| | Seeds used in development / calibration | 29, 31 | |
|
|
| --- |
|
|
| ## Dataset splits |
|
|
| | Split | Purpose | Seeds | n triples | Status | |
| |---|---|---|---|---| |
| | `dev` | Calibration (rho dial) | 29, 31 | 200 | Released | |
| | `test` | Confirmatory evaluation | 41, 43 | 200 | Released | |
| | `forced_choice` | One analog + one distractor per query | all | see above | Released | |
| | `library` | Query against a pool of 24 indexed cases | all | see above | Released | |
|
|
| The **forced-choice** split presents each query with exactly one true analog |
| and one star-rewired distractor; r@1 = 1 means the system always ranks the |
| analog first. |
|
|
| The **library** split presents each query against a 24-case indexed library; |
| r@1 measures whether the structural match tops the library ranking. |
|
|
| --- |
|
|
| ## Intended use |
|
|
| SSB is intended as a **diagnostic test** for retrieval systems that claim to |
| match on relational structure rather than surface similarity: |
|
|
| 1. **Structural retrieval systems** (structure-mapping engines, SME-style, |
| predicate-lattice-based) — the benchmark was designed to reward these. |
| 2. **Ablation studies** — a system that degrades from structural to surface |
| retrieval should drop from r@1 ≈ 1.0 to r@1 ≈ 0.0 on SSB. |
| 3. **Unit testing** — the forced-choice split is included in the SMA-1 test |
| suite as gate G4 (`test_macfac_lattice_bridges_disjoint_vocabularies`). |
|
|
| SSB is **not** intended as a benchmark for: |
| - General-purpose information retrieval (no natural language; no text documents) |
| - Semantic similarity (there is no semantic content — functors are arbitrary symbols) |
| - Knowledge graph completion (no real-world entities or relations) |
|
|
| --- |
|
|
| ## Limitations and caveats |
|
|
| 1. **Synthetic by construction.** SSB uses randomly generated functor names and |
| artificially constructed predicate lattices. Performance on SSB does not |
| directly predict performance on real-domain retrieval tasks (see the 5-domain |
| agentic suite in the SMA-1 paper for real-domain evaluation). |
|
|
| 2. **The lattice is declared, not learned.** The predicate lattice used by SMA |
| is supplied at evaluation time. A system without a compatible lattice (e.g. |
| pure BM25, dense RAG) will score 0.000 by construction — the benchmark is a |
| test of whether the mechanism exists, not how well it generalises to unseen |
| lattices. |
|
|
| 3. **Chain structure only.** The current generator uses chain-shaped base cases |
| (linear predicate chains). Richer topologies (trees, DAGs) are not yet in |
| the benchmark. |
|
|
| 4. **Small n.** Confirmatory evaluation uses n = 100 per seed × 2 seeds = 200 |
| triples. Statistical power is sufficient for the observed effect sizes |
| (δ = 0.895) but marginal tests may lack power. |
|
|
| 5. **Development contamination risk.** The calibration seeds (29, 31) were used |
| to set the rho = 0.95 dial; confirmatory seeds (41, 43) were reserved and |
| never inspected during development. The protocol is documented in |
| `configs/preregistration.md`. |
|
|
| --- |
|
|
| ## Source repository |
|
|
| ``` |
| https://github.com/ayazkhan27/sma-1 |
| ``` |
|
|
| Generating script: `scripts/confirmatory_battery.py --task ssb` |
|
|
| Confirmatory outputs: `reports/confirmatory/ssb_{rows,stats,summary}.csv` |
|
|
| Gate test: `tests/test_macfac.py::test_macfac_lattice_bridges_disjoint_vocabularies` |
|
|
| --- |
|
|
| ## Citation |
|
|
| ```bibtex |
| @software{khan2026sma, |
| author = {Ayaz Khan}, |
| title = {SMA-1: Structure-Mapping Agentic Memory}, |
| year = {2026}, |
| license = {Apache-2.0}, |
| url = {https://github.com/ayazkhan27/sma-1} |
| } |
| ``` |
|
|
| --- |
|
|
| ## License |
|
|
| Apache-2.0. See `LICENSE` at the repository root. |
|
|
| Benchmark construction uses no third-party data; all functor names are randomly |
| generated. The predicate lattice is fully synthetic. |
|
|
