| 1 | −% part03_data — to be written (Phase 7) |
1 | +% ============================================================================ |
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2 | +% Part III — Data and Systematic Review Protocol |
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3 | +% Written by Agent L (Part III instance), 2026-11-03. Every corpus number is a macro from tables/numbers.tex |
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4 | +% (generated by tables/make_numbers.py from data/metadata/prisma_counts.json and linkage_report.json). |
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5 | +% Sources of truth: RESEARCH_PLAN.md §2–§3, protocol/PROTOCOL.md, protocol/amendments.csv, |
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6 | +% reports/PHASE0_FEASIBILITY.md, data/raw/README.md, ingestion/*.py, systematic_review/define_corpus.py. |
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7 | +% ============================================================================ |
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8 | + |
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9 | +\section{Information sources and conditions of access} |
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10 | +\label{sec:data-sources} |
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11 | + |
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12 | +A field-level mapping study stands or falls with the bibliographic databases on which it is built. The choice |
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13 | +of sources determines which works can be observed at all, how reliably they can be dated and typed, whether |
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14 | +citation links are available, and under what licence derived data may be redistributed. This part documents |
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15 | +these choices for WP44 and reports, stage by stage, how the mapping corpus was assembled from the raw |
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16 | +sources. The exposition follows the order of the pipeline (identification, linkage, deduplication, |
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17 | +eligibility, scope, dating) and closes with the quality indicators and the research-integrity procedures that |
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18 | +govern every later analysis. The reporting structure is modelled on the PRISMA 2020 items that apply to a |
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19 | +mapping study \citep{page2021prisma,page2021prismaee}; items concerned with risk of bias and effect measures |
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20 | +have no counterpart in a bibliometric design and are replaced, as PRISMA-ScR does for scoping reviews |
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21 | +\citep{tricco2018prismascr}, by indicators of metadata quality and coverage (Section~\ref{sec:data-quality}). |
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22 | +The search-reporting recommendations of PRISMA-S \citep{rethlefsen2021prismas} are followed to the extent |
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23 | +that a database-scope strategy without keyword queries permits. |
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24 | + |
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25 | +\subsection{Why a multi-source design} |
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26 | + |
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27 | +No single database indexes computer science completely, and the gaps are not random. The venue-centred |
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28 | +coverage of DBLP, the publisher-centred coverage of Crossref, the preprint-centred coverage of arXiv and the |
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29 | +aggregating coverage of OpenAlex each miss a distinct part of the literature and type the part they do cover |
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30 | +in distinct ways. Comparative studies of bibliographic data sources have documented large differences in |
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31 | +coverage between Web of Science, Scopus, Dimensions, Crossref and Microsoft Academic |
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32 | +\citep{visser2021comparison,martinmartin2021comparison}, and the journal-level coverage of the two commercial |
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33 | +indexes is known to under-represent conference proceedings, which carry a large share of computer-science |
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34 | +output \citep{mongeon2016coverage}. For the open successor of Microsoft Academic, OpenAlex, the first |
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35 | +independent assessments report strong coverage of works with DOIs together with weaker and uneven metadata on |
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36 | +affiliations, document types and references \citep{alperin2024openalex,culbert2025openalex, |
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37 | +scheidsteger2023openalex,delgadoquiros2024completeness}. These findings motivate the design adopted here: one |
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38 | +source supplies the backbone (OpenAlex), a second supplies the definition of what counts as computer science |
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39 | +(DBLP), a third supplies the preprint layer and its dates (arXiv), and a fourth checks the coverage of a |
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40 | +subfield with a dense, curated venue structure (the ACL Anthology). Crossref is used for verification only. |
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41 | + |
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42 | +\subsection{OpenAlex} |
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43 | + |
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44 | +OpenAlex \citep{priem2022openalex} is the backbone of the corpus. It supplies, for every work, the |
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45 | +identifiers (OpenAlex~W identifier, DOI, arXiv identifier where present), the publication date and type, the |
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46 | +title and an inverted-index abstract where available, the venue (source) and its type, the authorships with |
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47 | +institutions and countries, the topic assignment at three levels (field, subfield, topic) with a primary |
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48 | +topic, the list of referenced works (the citation graph), the open-access status and licence, and the |
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49 | +field-weighted citation impact together with yearly citation counts. OpenAlex is released under the CC0 |
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50 | +public-domain dedication, which permits redistribution of record-level derived data. |
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51 | + |
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52 | +Two access routes exist and both were used, for different purposes. The public snapshot is a versioned bulk |
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53 | +release in gzipped JSON Lines, published in a public S3 bucket; the release used here is dated |
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54 | +2026-10-14 and comprises 1{,}898 part files for the \emph{works} entity, 675.3~GB compressed, with a manifest |
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55 | +listing the record count of each file. The snapshot was streamed from the primary compute node, each file's |
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56 | +content length checked against the manifest and a SHA-256 of the compressed bytes recorded in a SQLite ledger |
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57 | +before parsing; every one of the 1{,}898 files parsed without error and the sum of the per-file record counts |
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58 | +equals the manifest total of \LinkSlimTotal{} works. Two outputs were written during this single pass. The |
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59 | +first is the full JSON record of every work carrying \emph{any} topic in OpenAlex field~17 (Computer Science) |
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60 | +with a publication year between 2018 and 2026, stored as Zstandard-compressed JSON Lines and partitioned by |
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61 | +the snapshot's own date partitions (\LinkOaCsRecords{} records, about 20~GB). The second is a \emph{slim} |
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62 | +table of every work in the snapshot (identifier, DOI, year, type, primary topic, subfield, field and domain, |
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63 | +citation count and a few flags), kept in Parquet so that works cited by computer-science papers but published |
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64 | +in other fields can be resolved for the interdisciplinary analyses of Part~VIII (decision D2 of |
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65 | +\texttt{RESEARCH\_PLAN.md}). Records flagged by OpenAlex as XPAC expansion records are retained at this stage |
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66 | +with their flag so that the exclusion decision can be taken, and counted, later (Section~\ref{sec:data-eligibility}). |
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67 | +The smaller entity snapshots (topics, subfields, fields, domains, sources, institutions, publishers, funders, |
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68 | +concepts) were downloaded the same day with a per-file SHA-256 ledger; author entities were not downloaded |
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69 | +because the authorship data embedded in each work record suffice for the analyses planned. |
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70 | + |
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71 | +The second route is the REST API. Without an API key the public endpoint operates under a shared daily budget |
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72 | +of USD~0.10, list-and-filter calls are priced at USD~0.0001 each, and cursor paging is unavailable, so that a |
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73 | +single filtered query cannot return more than 10{,}000 results through basic paging. Single-record lookups by |
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74 | +identifier are free. The API was therefore used for two narrowly defined tasks. First, an incremental harvest |
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75 | +of works with any computer-science topic and a publication date between 2026-10-01 and 2026-11-02, intended |
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76 | +to capture records added after the snapshot was cut; the harvest is sliced by publication day and, where a day |
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77 | +exceeds the paging limit, split into records with a computer-science primary field and records without one. |
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78 | +Raw JSON pages are stored verbatim under a dated directory with a ledger of counts and cost, and the job |
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79 | +resumes on the following day when the budget is exhausted. Second, free single-record lookups by DOI serve as |
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80 | +one of the verification routes for the bibliography of this manuscript (Section~\ref{sec:data-integrity}). |
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81 | +A free API key, which would raise the daily budget, requires the principal investigator to act on an e-mail |
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82 | +and was deliberately not obtained without instruction; the mandate forbids assuming credentials that have not |
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83 | +been tested. |
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84 | + |
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85 | +\subsection{DBLP} |
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86 | + |
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87 | +The DBLP computer science bibliography \citep{ley2002dblp,ley2009dblp} is a curated, venue-centred index that |
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88 | +has for three decades defined, in practice, the set of journals and conference series regarded as computer |
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89 | +science. It is used here in that capacity: a work indexed by DBLP is in computer science by construction, and |
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90 | +DBLP venue streams feed the taxonomy of Part~IV. The complete XML dump (\texttt{dblp.xml.gz}, dated 2026-11-02 |
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91 | +22:39~UTC, 1.12~GB) was downloaded together with its DTD and MD5 checksum, the checksum verified, and the file |
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92 | +parsed with a validating XML parser into one row per publication record (articles, conference papers, |
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93 | +proceedings volumes, books, book chapters, doctoral and master's theses, data records; the \texttt{www} |
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94 | +person records are skipped). The whole archive was kept so that per-year counts are available for the |
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95 | +historical baseline and for context. The DBLP dump is released under the Open Data Commons Attribution licence |
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96 | +(ODC-BY~1.0). DBLP contributes, in addition to the scope definition, author person identifiers, venue streams, |
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97 | +and DOI links for most records; the \texttt{ee} fields were also scanned for arXiv URLs, with a result reported |
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98 | +in Section~\ref{sec:data-linkage}. |
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99 | + |
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100 | +\subsection{arXiv} |
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101 | + |
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102 | +The arXiv e-print repository \citep{ginsparg2011arxiv} is the main preprint channel of computer science and, |
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103 | +for the period under study, the place where a large share of the most cited work first appeared. Its |
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104 | +metadata are harvested through the OAI-PMH interface (\texttt{set=cs}, \texttt{metadataPrefix=arXiv}) in |
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105 | +monthly datestamp windows from January 2018 to 2 November 2026. The harvester waits at least 3.5~s between |
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106 | +requests and honours \texttt{Retry-After} headers; every raw XML page is kept verbatim as the immutable |
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107 | +snapshot and parsed afterwards into a single Parquet table. Two properties of OAI-PMH matter for what follows. |
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108 | +The \texttt{from}/\texttt{until} parameters filter on the record's \emph{datestamp}, the time of its last |
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109 | +update, so that a monthly window contains every record updated in that month, not every record first |
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110 | +submitted then; duplicates across windows are resolved at parse time with the latest datestamp winning. The |
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111 | +\texttt{created} element gives the first submission date, which is the date used throughout this study for |
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112 | +preprints. The harvest returned \LinkArxivCsRecords{} distinct records, of which |
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113 | +\LinkArxivCreatedTwoZeroOneEightTwoZeroTwoSix{} were first submitted in 2018--2026; the remainder are older |
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114 | +e-prints updated during the window. The arXiv metadata are released for reuse under the repository's metadata |
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115 | +terms; e-prints themselves are governed by per-paper licences and are downloaded, for the high-priority set |
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116 | +only, within those licences and at the repository's rate limits. The use of arXiv as a research dataset, and |
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117 | +the caveats attached to its category labels and versioning, are discussed by \citet{clement2019arxiv}. |
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118 | + |
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119 | +\subsection{ACL Anthology} |
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120 | + |
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121 | +The ACL Anthology is the curated archive of the computational-linguistics community and has itself served as a |
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122 | +bibliometric corpus \citep{radev2013acl}. Its BibTeX export with abstracts (\texttt{anthology+abstracts.bib.gz}, |
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123 | +46.7~MB, SHA-256 recorded) was downloaded on 2026-11-02 and parsed into a table of 138{,}796 entries, of which |
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124 | +\LinkAclRecords{} are conference papers or journal articles and \LinkAclTwoZeroOneEightTwoZeroTwoSix{} fall in |
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125 | +2018--2026. The Anthology plays a diagnostic role: because its venue structure is complete and hand-maintained, |
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126 | +the share of its entries that the backbone can be matched to is a direct measure of OpenAlex coverage for a |
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127 | +subfield that publishes overwhelmingly in conference proceedings. It also supplies abstracts for those entries |
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128 | +in which OpenAlex has none. The export is licensed CC~BY~4.0. |
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129 | + |
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130 | +\subsection{Crossref, Semantic Scholar and other sources} |
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131 | + |
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132 | +Crossref \citep{hendricks2020crossref} is the registration agency behind most DOIs in the corpus and offers |
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133 | +open metadata through a REST API with a polite pool. It is not used to build the corpus, whose backbone |
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134 | +already carries Crossref-derived metadata through OpenAlex, but for three verification purposes: resolution of |
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135 | +every DOI cited in this manuscript, a cross-check of publisher-assigned document types on samples, and a |
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136 | +cross-check of citation counts (\texttt{is-referenced-by-count}) on a sample of highly cited works in |
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137 | +Part~IX. |
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138 | + |
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139 | +The Semantic Scholar Academic Graph \citep{kinney2023s2} was listed in the mandate among the priority sources |
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140 | +because of two signals it alone provides, the influential-citation classification and citation intent. At the |
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141 | +time of the feasibility audit, anonymous requests to its API returned HTTP~429 with an instruction to apply for |
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142 | +a key, and the bulk-dataset endpoint requires a key outright. In keeping with the rule that inaccessible data |
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143 | +be recorded rather than circumvented, Semantic Scholar is recorded as unavailable (decision D3) and no analysis |
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144 | +in this manuscript uses influential-citation or citation-intent signals; where Part~VIII discusses the |
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145 | +strength of citation links, it does so with OpenAlex reference lists and the knowledge-graph extraction of |
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146 | +Part~IV, whose limits are stated there. The Microsoft Academic Graph \citep{wang2020mag}, from which OpenAlex |
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147 | +inherited much of its historical coverage, was discontinued at the end of 2021 and is not an independent source |
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148 | +for the period studied. Kaggle credentials for the arXiv snapshot distributed there were absent and were not |
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149 | +needed, OAI-PMH being sufficient. Benchmark repositories and code-hosting platforms enter only in the |
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150 | +reproducibility and benchmark analyses scoped in Part~IV and are not part of the bibliographic corpus. |
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151 | + |
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152 | +Table~\ref{tab:data-sources} summarises the sources, the access route, the licence and the role of each. |
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153 | + |
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154 | +\begin{table}[htbp] |
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155 | +\centering\small |
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156 | +\caption{Information sources of the WP44 corpus (all accessed 2026-11-02/03).} |
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157 | +\label{tab:data-sources} |
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158 | +\begin{tabularx}{\textwidth}{lXll} |
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159 | +\toprule |
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160 | +Source & Access and snapshot & Licence & Role \\ |
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161 | +\midrule |
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162 | +OpenAlex works snapshot & public S3 bucket, release 2026-10-14, 1{,}898 JSONL files, \LinkSlimTotal{} works & CC0 & backbone: identifiers, dates, types, topics, authorships, references, abstracts, OA status \\ |
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163 | +OpenAlex REST API & no key; USD~0.10 per day shared budget; increment 2026-10-01 to 2026-11-02; single lookups & CC0 & post-snapshot increment; reference verification \\ |
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164 | +DBLP & XML dump 2026-11-02 22:39~UTC, MD5 verified & ODC-BY~1.0 & computer-science scope; venue streams; author identifiers \\ |
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165 | +arXiv & OAI-PMH set \texttt{cs}, 2018-01 to 2026-11, raw pages kept & arXiv metadata terms & preprint layer; first-submission dates; categories \\ |
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166 | +ACL Anthology & BibTeX export with abstracts, 2026-11-02 & CC~BY~4.0 & coverage check for NLP venues; abstracts \\ |
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167 | +Crossref & REST API, polite pool & open metadata & verification of DOIs, types and citation counts \\ |
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168 | +Semantic Scholar & API key required; anonymous calls refused & --- & \emph{unavailable, recorded} \\ |
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169 | +\bottomrule |
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170 | +\end{tabularx} |
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171 | +\end{table} |
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172 | + |
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173 | +\section{Identification: what each source contributes} |
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174 | +\label{sec:data-identification} |
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175 | + |
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176 | +There is no keyword search in this study. A mapping of an entire discipline cannot be defined by a query |
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177 | +string without importing the vocabulary of whoever wrote it; it is defined instead by database scope filters |
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178 | +that are themselves documented and reproducible, which is the strategy recommended for mapping studies in |
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179 | +software engineering and adopted here for computer science as a whole |
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180 | +\citep{petersen2008mapping,petersen2015mapping}. The identification stage (S0 in the notation of the research |
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181 | +plan) therefore consists of four scope filters, one per source, applied to immutable snapshots whose dates and |
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182 | +hashes are recorded in \texttt{data/raw/README.md}. |
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183 | + |
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184 | +\subsection{Scope filters} |
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185 | + |
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186 | +The OpenAlex filter retains every work with at least one topic, primary or secondary, in field~17 and a |
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187 | +publication year in $[2018, 2026]$. The choice of \emph{any} topic rather than the primary topic is deliberate |
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188 | +and conservative at this stage: a work whose primary topic lies in, say, statistics or electrical engineering |
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189 | +but which carries a secondary computer-science topic is a candidate, and the decision whether it belongs to |
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190 | +the core or to the penumbra is deferred to the eligibility stage, where it is made explicit and counted |
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191 | +(Section~\ref{sec:data-core}). The filter yields |
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192 | +\PrismaIdentifiedOpenalexCsTopicTwoZeroOneEightTwoZeroTwoSixPassOne{} records in the first pass over the |
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193 | +snapshot. The DBLP filter retains the publication records of type article, inproceedings, incollection, book, |
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194 | +phdthesis and data with a year in $[2018, 2026]$: \PrismaIdentifiedDblpTwoZeroOneEightTwoZeroTwoSix{} records. |
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195 | +The arXiv filter retains the records of set \texttt{cs} whose first submission falls in the window: |
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196 | +\PrismaIdentifiedArxivCsTwoZeroOneEightTwoZeroTwoSix{} records. The ACL filter retains the conference papers |
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197 | +and journal articles of the Anthology with a year in the window: |
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198 | +\PrismaIdentifiedAclTwoZeroOneEightTwoZeroTwoSix{} records. The four counts overlap heavily, since most DBLP |
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199 | +and ACL records and a majority of arXiv records also exist in OpenAlex; the overlap is resolved by record |
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200 | +linkage, not by summation, and no total of identified records is reported as if the sources were disjoint. |
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201 | + |
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202 | +\subsection{The OpenAlex topic classifier as a scope instrument} |
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203 | + |
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204 | +Because the OpenAlex filter relies on an automated topic classifier, its properties bear on everything |
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205 | +downstream. OpenAlex assigns to each work up to three topics from a fixed list of 4{,}516, organised in 252 |
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206 | +subfields, 26 fields and four domains; the assignment is made by a model applied to the title, abstract and |
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207 | +venue, and the field label of a work is inherited from its topics rather than assigned directly. Two |
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208 | +consequences follow. A work can be labelled computer science because one of its topics belongs to field~17 |
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209 | +even when its content is only marginally computational, and conversely a work in a computer-science venue can |
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210 | +receive no computer-science topic when its abstract is missing or its vocabulary is domain-specific. The first |
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211 | +error inflates the candidate set with what will be called the penumbra; the second removes genuine |
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212 | +computer-science works from the first-pass candidate set. DBLP is used to correct the second error, which is |
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213 | +why the linkage stage has two passes (Section~\ref{sec:data-linkage}). The literature on OpenAlex has so far |
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214 | +examined its coverage and metadata completeness rather than the accuracy of its topic labels |
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215 | +\citep{alperin2024openalex,delgadoquiros2024completeness}; the present study treats the labels as a scope |
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216 | +instrument whose errors are bounded by the DBLP and arXiv memberships and quantified in |
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217 | +Section~\ref{sec:data-quality}, not as ground truth. |
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218 | + |
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219 | +\subsection{Verification of the scale against the mandate} |
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220 | + |
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221 | +The mandate set planning targets of more than one million candidate records and more than one hundred |
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222 | +thousand deeply classified records, subject to availability. The feasibility audit established, before any |
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223 | +ingestion, that the OpenAlex API alone reported more than six million works with a computer-science primary |
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224 | +field in 2018--2026 and that the DBLP dump held more than four million records in the same years; the targets |
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225 | +were therefore attainable without recourse to any restricted source. The audit also established what was |
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226 | +\emph{not} attainable: a Semantic Scholar key, an OpenAlex key, Kaggle credentials and the AWS command-line |
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227 | +tool were all absent, and the ingestion was designed around their absence (HTTPS streaming of the public |
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228 | +bucket, basic paging of the public API). The record of this audit is \texttt{reports/PHASE0\_FEASIBILITY.md}. |
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229 | + |
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230 | +\section{Record linkage across sources} |
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231 | +\label{sec:data-linkage} |
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232 | + |
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233 | +The four candidate sets describe overlapping populations with different identifiers. Record linkage (stage S1) |
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234 | +establishes, for each DBLP, arXiv and ACL record, the OpenAlex work it describes, so that one node per work |
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235 | +can be formed with the union of the metadata. The methods are deterministic and ordered by reliability; the |
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236 | +probabilistic framework of \citet{fellegi1969linkage} is not needed because the available keys (DOI, arXiv |
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237 | +identifier) are close to exact, and the residual title-based step is restricted to blocks where it is |
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238 | +unambiguous. The implementation follows the standard decomposition of data matching into key normalisation, |
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239 | +blocking, comparison and classification \citep{christen2012matching}; Part~IV gives the formal statement of the |
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240 | +keys and of the precision-estimation design, and this section reports what was done and what it produced. |
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241 | + |
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242 | +\subsection{Keys and matching order} |
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243 | + |
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244 | +All keys are normalised before comparison. DOIs are lower-cased. arXiv identifiers are lower-cased and |
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245 | +stripped of their version suffix (\texttt{v2}, \texttt{v3}, \ldots), so that all versions of an e-print map to |
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246 | +one identifier. Titles are reduced to a normalised string by lower-casing and deleting every character that is |
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247 | +not a letter or digit; the normalised title is used only when it has at least 25 characters, is unique within |
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248 | +its source, and is unique within OpenAlex, which is the blocking rule that keeps the title step from |
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249 | +producing spurious links between generic titles. |
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250 | + |
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251 | +For DBLP, the order is: (i) DOI equality, (ii) arXiv identifier equality, restricted to records not yet linked |
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252 | +on either side, (iii) normalised title equality with a year difference of at most one, restricted to records |
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253 | +not yet linked on either side. The DOI step linked \LinkLinkDblpOaDoi{} records and the title step |
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254 | +\LinkLinkDblpOaTitleYear{}; the arXiv step linked none, because the extraction of arXiv URLs from the DBLP |
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255 | +\texttt{ee} fields returned no candidate (\LinkDblpWithArxiv{} records with an extracted identifier). The most |
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256 | +plausible reason is that DBLP now records the arXiv version of its CoRR entries as a DataCite DOI of the form |
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257 | +\texttt{10.48550/arXiv.*}, which the DOI step already handles; the step is kept in the pipeline because other |
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258 | +dumps may differ. In total \LinkDblpLinkedDistinct{} of the \LinkDblpTwoZeroOneEightTwoZeroTwoSix{} DBLP |
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259 | +records in the window were linked to an OpenAlex work after the first pass, leaving \LinkDblpUnlinked{} |
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260 | +unlinked. The composition of the unlinked set is informative: \LinkDblpUnlinkedByTypeArticle{} journal |
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261 | +articles, \LinkDblpUnlinkedByTypeInproceedings{} conference papers, \LinkDblpUnlinkedByTypePhdthesis{} |
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262 | +doctoral theses, \LinkDblpUnlinkedByTypeData{} data records, \LinkDblpUnlinkedByTypeIncollection{} chapters |
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263 | +and \LinkDblpUnlinkedByTypeBook{} books. Of these, \LinkDblpUnlinkedWithDoiInSlim{} carry a DOI that |
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264 | +\emph{does} exist in the slim table of all OpenAlex works, which means the work is in OpenAlex but was not |
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265 | +caught by the computer-science topic filter; this is the second error of the topic classifier described above |
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266 | +and the reason for the second pass. |
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267 | + |
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268 | +For arXiv, the order is: (i) arXiv identifier equality against the identifier OpenAlex records for the work, |
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269 | +(ii) DOI equality for e-prints that carry a journal DOI, (iii) normalised title equality with a year |
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270 | +difference of at most two, the wider tolerance reflecting the typical lag between a preprint and its published |
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271 | +version \citep{lin2020preprints}. The steps linked \LinkLinkArxivOaArxivId{}, \LinkLinkArxivOaDoi{} and |
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272 | +\LinkLinkArxivOaTitleYear{} records respectively, for \LinkArxivLinkedDistinct{} distinct e-prints linked. |
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273 | +For the ACL Anthology, the order is: (i) DOI equality, (ii) equality between the Anthology identifier and the |
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274 | +identifier embedded in an \texttt{aclanthology.org} landing-page URL among the work's OpenAlex locations, |
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275 | +(iii) normalised title equality with a year difference of at most one. The steps linked |
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276 | +\LinkLinkAclOaDoi{} records by DOI and \LinkLinkAclOaTitleYear{} by title, with the URL step contributing the |
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277 | +remainder, for \LinkAclLinkedDistinctTwoZeroOneEightTwoZeroTwoSix{} distinct 2018--2026 entries linked out of |
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278 | +\LinkAclTwoZeroOneEightTwoZeroTwoSix{}; the residual is examined in Section~\ref{sec:data-quality} as a |
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279 | +measure of OpenAlex coverage of conference-heavy subfields. |
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280 | + |
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281 | +\subsection{The second snapshot pass} |
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282 | + |
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283 | +A DBLP record whose DOI resolves to an OpenAlex work outside the topic filter is, by the scope rule, a |
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284 | +computer-science work that the first pass did not load. The same situation arises for arXiv e-prints whose |
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285 | +journal DOI exists in OpenAlex without a computer-science topic. The linkage script therefore writes the list |
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286 | +of OpenAlex identifiers that are needed but not loaded: \LinkNeededOaIdsSecondPassDblpDoi{} identifiers from |
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287 | +DBLP DOIs and \LinkNeededOaIdsSecondPassArxivDoi{} from arXiv DOIs. A second pass over the works snapshot, |
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288 | +restricted to this identifier list, retrieves the full records of these works; they are normalised into the |
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289 | +same Parquet tables with a \texttt{\_p2} suffix, the DuckDB views are rebuilt over the union of both passes, |
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290 | +and linkage is re-run so that the DBLP-linked set gains the works that the topic classifier had missed. The |
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291 | +second pass is what makes the DBLP membership rule of Section~\ref{sec:data-core} operational: without it, |
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292 | +``DBLP-indexed'' would silently mean ``DBLP-indexed and labelled computer science by OpenAlex'', and the DBLP |
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293 | +correction would be void precisely where it matters. DBLP records with no OpenAlex counterpart after both |
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294 | +passes (\PrismaLinkedDblpOnlyNoOpenalexRecord{} records before the second pass) are kept in a separate table |
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295 | +with their year and type and are reported as such; they enter the volume counts of Part~IX only in the |
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296 | +sensitivity analysis that adds DBLP-only records, because they lack the abstracts, references and affiliations |
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297 | +on which every other indicator depends. Most of them are journal articles and conference papers with a DOI |
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298 | +that OpenAlex does not hold at all, together with doctoral theses, which DBLP indexes from university |
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299 | +repositories that OpenAlex covers unevenly. |
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300 | + |
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301 | +\subsection{Precision of the linkage} |
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302 | + |
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303 | +Exact-key links are correct whenever the key is correct in both sources; the known failure modes are DOIs |
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304 | +reassigned by publishers between versions, DOIs registered for a proceedings volume rather than a paper, and |
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305 | +e-prints whose OpenAlex record points to a different version. Title-based links can fail on near-identical |
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306 | +titles of distinct works (extended abstracts and full papers, workshop and conference versions). The protocol |
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307 | +pre-specifies the estimation of linkage precision on a sample of 500 DBLP--OpenAlex pairs stratified by method, |
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308 | +with automatic agreement checks (normalised-title similarity, year difference, first-author surname) and a |
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309 | +200-pair subsample reserved for the principal investigator (checkpoint H-1). The sampling script draws 250 DOI |
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310 | +links, 200 title links and 50 arXiv links with a fixed seed; since the arXiv step produced no links in this |
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311 | +dump, the realised sample has 450 pairs, and the precision estimate for the arXiv step is undefined rather |
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312 | +than reported as perfect. At the time of writing the sampling script exists but the sample has not been drawn and the |
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313 | +human checkpoint is unsigned; the automatic agreement rates and the human verdicts will be reported in Part~IX |
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314 | +and Appendix~B, and every conclusion that depends on the title-based links is labelled as pending human review |
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315 | +until H-1 is signed. |
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316 | + |