By Anonymous User
Review Details
Reviewer has chosen to be Anonymous
Overall Impression: Average
Content:
Technical Quality of the paper: Average
Originality of the paper: Yes, but limited
Adequacy of the bibliography: Yes, but see detailed comments
Presentation:
Adequacy of the abstract: Yes
Introduction: background and motivation: Good
Organization of the paper: Needs improvement
Level of English: Satisfactory
Overall presentation: Average
Detailed Comments:
The paper introduces RoomKG, a deterministic room-grid benchmark for evaluating long-term memory in partially observable neurosymbolic agents. The environment is represented in RDF/KG form, and the authors compare symbolic KG/Temp. KG agents with LSTM and Transformer baselines. The topic is relevant and the benchmark direction is promising. However, I recommend major revisions, because several methodological and representational issues currently limit how the results can be interpreted confidently.
The temporal RDF/KG representation should be clarified and positioned more carefully. The paper repeatedly refers to RDF 1.2-annotated triples, but the concrete representation remains hard to inspect from the manuscript alone. Since no serialized RDF/Turtle artifacts seem to be provided, the claimed RDF representation is difficult to verify without reconstructing the graph generation from code. In the supplement, the implementation appears to use old-style RDF blank-node reification, with rdf:Statement, rdf:subject, rdf:predicate, and rdf:object, plus qualifier triples. This is valid RDF, but it is different from the claimed RDF 1.2 triple terms/reifiers annotation syntax. The paper should include a small side-by-side example showing the intended RDF 1.2-style representation and the concrete artifact representation. It should also provide concrete RDF/Turtle examples for a hidden-state fragment, a local observation, and a temporal memory entry.
The paper should also better position its temporal representation against prior temporal and spatio-temporal RDF work, including Temporal RDF, named graphs/quads, RDF-star/RDF 1.2 annotations, stRDF/stSPARQL, OWL-Time, and RDF stream processing. In particular, temporal validity should be distinguished from memory-management metadata such as last_accessed and num_recalled.
The temporal memory operations are under-specified. The paper should define how insertion, repeated observation, update, query-time metadata update, eviction, deletion, and outdated or contradictory facts are handled. This is central for object-location tasks, where multiple observed locations of the same object may coexist unless the update semantics are explicitly defined.
The experimental protocol should be clarified. A compact train/test table should specify which environment components are shared and which are changed, including layout, wall dynamics, object behavior, query order, and random seeds. Without this, the reported generalization result remains ambiguous.
The reported results would benefit from stronger calibration. The currently best TKG result is better than the neural agent baselines, but its absolute score remains modest. The paper should add baselines such as a hidden-state oracle, a perfect-memory symbolic agent, an observation-only baseline, or a baseline siply using last-seen facts. These are important because the current absolute QA scores are otherwise difficult to interpret.
The symbolic vs neural comparison is substantially confounded. The symbolic agents use explicit graph retrieval and hand-designed exploration (BFS) policies, while the neural agents appear to learn a joint movement-and-answering policy. The neural baselines process observations in sequence, so temporal order is present implicitly, but they do not appear to receive explicit time, recency, currentness, or access-count features comparable to time_added, last_accessed, and num_recalled. Thus, the experiments compare KG versus TKG on the symbolic side, but do not include an analogous "temporal informed neural agent". Such a control would help separate the benefit of temporal information from the benefit of symbolic graph operations and hand-designed policies.
The hidden state notation should be introduced more carefully. The term s_t should be clearly distinguished from the local observation o_t and the agent's internal memory M_t. The deterministic question-move loop could also be formalized, since the order of answering, reward computation, object movement, agent movement, wall updates, observation, and memory update is currently too vague. In general, the paper would beenfit from more formal rigor, by introducing the used concepts with proper formal definitions.
Finally, the room-coverage results should be interpreted more cautiously. Room coverage is likely strongly influenced by the exploration policy and thus should not be treated as direct evidence for memory quality alone. The figures should also be improved for readability, especially Figures 1 (increase font size), 2 (maybe better show subgraph ur turtle example), 3 (distinguishable colors), and 5. Overall, the current experiments are informative for this controlled benchmark setting, but they do not yet justify broad claims about the effectiveness of temporal KG memory across agent architectures.