A Hybrid Quantitative Framework for the Chronological Reclassification of Indeterminate Ceramic Assemblages

The chronological classification of ceramic assemblages is frequently limited by the presence of large groups of fragments lacking secure phase attribution. These residual categories, often labelled as “indeterminate”, “no phase” or “SIN_INFO” (“no information”), distort phase distributions, weaken diversity and equitability indices, and reduce the interpretative coherence of archaeological datasets. This study develops a hybrid and fully traceable quantitative framework for the chronological reclassification of indeterminate ceramic materials, applied to the Neolithic assemblage from Tossal de les Basses / Cerro de las Balsas (Alicante, Spain). The initial dataset comprised 7,507 ceramic fragments and 387 stratigraphic units, with approximately 47% of fragments (NTE) and 52% of minimum number of individuals (MNI) lacking chronological attribution. The proposed protocol combines three complementary procedures: cosine similarity between techno-decorative profiles and phase centroids, supervised classification through Random Forest, and proportional/profile-based imputation. These outputs were integrated through a hierarchical decision model that prioritised agreement between methods, high-probability predictions and controlled similarity thresholds, while reserving lower-confidence profile-based assignment for unresolved cases. Rather than eliminating uncertainty, the framework transforms it into explicit, ranked and reproducible decision rules. The results enabled the formal reintegration of previously indeterminate materials into the chronological sequence of the site, improving stratigraphic consistency, phase comparability and the interpretative use of ceramic diversity indicators. The complete workflow was implemented through Python scripts, structured matrices and documented procedures, ensuring replicability, auditability and transferability to other archaeological contexts affected by high levels of ceramic indeterminacy陶瓷遗存组合的年代学分类工作，常因存在大量无法明确阶段归属的残片群体而受限。这类常被标记为“不确定归属”“无阶段”或“SIN_INFO”（无信息）的剩余类别，会扭曲阶段分布、削弱多样性与均匀性指数，并降低考古数据集的解读连贯性。本研究针对不确定归属的陶瓷遗存开发了一套混合型且完全可溯源的量化框架，用于年代学重新分类，并将其应用于西班牙阿利坎特省Tossal de les Basses / Cerro de las Balsas遗址的新石器时代遗存组合。初始数据集包含7507件陶瓷残片与387个地层单元，其中约47%的残片（NTE）与52%的最小个体数（MNI, Minimum Number of Individuals）缺乏年代学归属信息。 本研究提出的方案结合了三项互补流程：工艺装饰特征剖面与阶段质心之间的余弦相似度计算、基于随机森林（Random Forest）的监督分类，以及基于比例/特征剖面的插补法。研究通过层级决策模型整合上述输出结果，该模型优先考量不同方法间的一致性、高概率预测结果与可控的相似度阈值，同时为未解决的案例保留低置信度的特征剖面归属分配方式。 该框架并未消除不确定性，而是将其转化为明确、分级且可复现的决策规则。 研究结果使得此前无法确定归属的遗存得以正式归并入该遗址的年代序列，提升了地层一致性、阶段可比性以及陶瓷多样性指标的解读可用性。 完整工作流程通过Python脚本、结构化矩阵与有文档记录的流程实现，确保了研究的可复现性、可审计性，以及可迁移至其他存在高比例陶瓷遗存不确定归属问题的考古场景中。