The paper by Plutniak [1] presents a new method that uses refitting to help interpret stratigraphy using the topological distribution of conjoinable material culture. This new method opens up new avenues to the archaeological use of network analysis but also to assess the integrity of interpreted excavation layers. Beyond its evident applicability to standard excavation practice, the paper presents a series of characteristics that exemplify archaeological publication best practices and, as someone more versed in computational than in refitting studies I would like to comment upon.

It was no easy task to find adequate reviewers for this paper as it combines techniques and expertise that are not commonly found together in individual researchers. However, Plutniak, with help from three reviewers, particularly M. Peeples, a leading figure in archaeological applications of network science, makes a considerable effort to be accessible to non-specialist archaeologists. The core Topological Study of Archaeological Refitting (TSAR) method is freely accessible as the R package archeofrag, which is available at the Comprehensive R Archive Network (https://CRAN.R-project.org/package=archeofrag) that can be applied without the need to understand all its mathematical, graph theory and coding aspects. Beside these, an online interface including test data has been provided (https://analytics.huma-num.fr/Sebastien.Plutniak/archeofrag/), which aims to ease access to the method to those archaeologists inexperienced with R. Finally, supplementary material showing how to use the package and evaluating its potential through excellent examples is provided as both pdf and Rmw (Sweave) files. This is an important companion for the paper as it allows a better understanding of the methods presented in the paper and its practical application.

The author shows particular care in testing the potential and capabilities of the method. For example, a function is provided “frag.observer.failure” to test the robustness of the edge count method against the TSAR method, which is able to prove that TSAR can deal well with incomplete information. As a further step in this direction both simulated and real field-acquired data are used to test the method which further proves that archeofrag is not only able to quantitatively assess the mixture of excavated layers but to propose meaningful alternatives, which no doubt will add an increased methodological consistency and thoroughness to previous quantitative approaches to material refitting work, even when dealing with very complex stratigraphies.

All in all, this paper makes an important contribution to core archaeological practice through the use of innovative, reproducible and accessible computational methods. I fully endorse it for the conscious and solid methods it presents but also for its adherence to open publication practices. I hope that it can become of standard use in the reconstruction of excavated stratigraphical layers through conjoinable material culture.

[1] Plutniak, S. 2021. The Strength of Parthood Ties. Modelling Spatial Units and Fragmented Objects with the TSAR Method – Topological Study of Archaeological Refitting. OSF Preprints, q2e69, ver. 3 Peer-reviewed and recommended by PCI Archaeology. https://doi.org/10.31219/osf.io/q2e69.

The paper 'A database of lapidary artifacts in the Caribbean for the Ceramic Age' by Queffelec et al. [1] presents a description of a dataset of nearly 5000 lapidary artefacts from over 100 sites. The data are dominated by beads and pendants, which are mostly made from Diorite, Turquoise, Carnelian, Amethyst, and Serpentine. The raw material data is especially valuable as many of these are not locally available on the island. This holds great potential for exchange network analysis. The data may be especially useful for investigating one of the fundamental questions of this region: whether the Cedrosan and Huecan are separate, little related developments, with different origins, or variants or a single tradition [2].

In addition to metric and technological details about the artefacts, the data include a variety of locational details, including coordinates, distance to coast, and altitude. This enables many opportunities for future spatial analysis and geostatistical modelling to understand human behaviours relating to ornament production, use, and discard. I recommend the authors make a minor revision to Table 1 (spatial coverage of the dataset) to make the column with the citations conform to the same citation style used in the rest of the text.

I warmly commend the authors for making transparency and reproducibility a priority when preparing their manuscript. Their use of the R Markdown format for writing reproducible, dynamic documents [3] is highly impressive. This is an excellent example for others in the international archaeological science community to follow. The paper is especially useful for researchers who are new to R and R Markdown because of the elegant and accessible way the authors document their research here.

[1] Queffelec, A., Fouéré, P. and Caverne, J.-B. 2021. A database of lapidary artifacts in the Caribbean for the Ceramic Age. SocArXiv, 7dq3b, ver. 4 Peer-reviewed and recommended by PCI Archaeology. https://doi.org/10.31235/osf.io/7dq3b

[2] Reed, J. A. and Petersen, J. B. 2001. A comparison of Huecan and Cedrosan Saladoid ceramics at the Trants site, Montserrat. In Proceedings of the XVIIIth International Congress for Caribbean Archaeology (pp. 253-267).

[3] Marwick, B. 2017. Computational Reproducibility in Archaeological Research: Basic Principles and a Case Study of Their Implementation. Journal of Archaeological Method and Theory 24, 424–450. https://doi.org/10.1007/s10816-015-9272-9