Identifies which DOIs were added, removed or unchanged between an earlier and a later retrieval. This supports change tracking: re-running a search later and seeing exactly what is new.
Arguments
- old, new
scopus_records objects or character vectors of DOIs, representing the earlier (
old) and later (new) retrievals.
Value
A tibble of class scopus_doi_diff with columns doi and status,
where status is a factor with levels "added" (in new only),
"removed" (in old only) and "unchanged" (in both). Rows are sorted by
status then DOI, in byte order, so the order is the same under every
locale and in the Python twin. The integer attributes n_old_without_doi
and n_new_without_doi count the records (or vector elements) on each
side that had no DOI and so were not compared. Printing shows the counts
in each category, and those records where there are any.
Details
A record without a DOI cannot be compared this way, and 'Scopus' gives no
DOI to a share of what it indexes, more of it in the arts and humanities and
among books and proceedings (Gorraiz et al., 2016). Such records are left out
of the rows and counted in the attributes n_old_without_doi and
n_new_without_doi and on the printed line. scopus_diff_records()
compares the records themselves, matching on the 'Scopus' identifier.
References
Gorraiz, J., Melero-Fuentes, D., Gumpenberger, C., & Valderrama-Zurián, J.-C. (2016). Availability of digital object identifiers (DOIs) in Web of Science and Scopus. Journal of Informetrics, 10(1), 98–109. doi:10.1016/j.joi.2015.11.008
Examples
# A baseline retrieval and the same search re-run a year later, both taken
# from the bundled corpus of real articles: the second pull has gained the
# 2024 records and lost the first one to re-indexing. Eleven records in each
# pull carry no DOI, and the printed line says so.
baseline <- example_records[example_records$year <= 2023, ]
later <- example_records[-1, ]
scopus_diff_dois(old = baseline, new = later)
#> <scopus_doi_diff> 14 added, 1 removed, 112 unchanged, 11 earlier and 11 later
#> records without a DOI not compared
#> # A tibble: 127 × 2
#> doi status
#> <chr> <fct>
#> 1 10.1002/adfm.202315137 added
#> 2 10.1002/asia.202400548 added
#> 3 10.1002/slct.202302535 added
#> 4 10.1016/j.cej.2024.148822 added
#> 5 10.1016/j.diamond.2024.110842 added
#> 6 10.1016/j.isci.2024.111696 added
#> 7 10.1016/j.jallcom.2024.175000 added
#> 8 10.1016/j.jallcom.2024.177248 added
#> 9 10.1016/j.jpowsour.2024.234127 added
#> 10 10.1016/j.jpowsour.2024.236149 added
#> # ℹ 117 more rows