Identifies which records were added, removed or unchanged between an earlier
and a later retrieval, and gives each record's citation count in both.
scopus_diff_dois() compares DOIs alone, and this function compares the
records themselves, matched as scopus_combine(dedupe = TRUE) matches them.
A record without a DOI is therefore still tracked by its 'Scopus'
identifier, and two records under one DOI are not taken for one.
Arguments
- old, new
scopus_records objects, or data frames with a
scopus_idor adoicolumn, representing the earlier (old) and later (new) retrievals. Thetitle,yearandcitationscolumns are read where present.
Value
A tibble of class scopus_record_diff, one row per record, with the
columns status, scopus_id, doi, title, year, citations_old and
citations_new. status is a factor with levels "added" (in new
only), "removed" (in old only), "conflict" (see Details) and
"unchanged" (in both). Rows are sorted by status, then DOI, identifier
and title, in byte order, so the order is the same under every locale and
in the Python twin. The integer attributes n_old_without_id_or_doi and
n_new_without_id_or_doi count the records on each side that carried
neither key and so were not compared. Printing shows the counts in each
category, and those records where there are any.
Details
Two records are one record when they share a 'Scopus' identifier, or when
they share a DOI and one of them lacks an identifier. DOIs are compared as
scopus_extract_dois() compares them, without resolver prefixes and
ignoring case. Records with different identifiers are never matched, even
under one DOI, since 'Scopus' gives one DOI to distinct papers as well as
holding duplicate records of one paper (scopus_combine() gives the
sources).
A record found in one retrieval only is a "conflict" where the other
retrieval gives its DOI to a different record. It may have been re-indexed
under a new identifier, or it may be a distinct paper sharing the DOI. Only
the two records themselves can tell, so it is counted neither as added nor
as removed. A record without an identifier whose DOI two identified
records carry is in the same position. A record with neither an identifier
nor a DOI cannot be matched at all, and is left out of the rows and counted.
scopus_id is the identifier the record was matched on, missing for a
record matched on its DOI alone. doi is the DOI without its resolver
prefix, in the case the record gives it. doi, title and year come from
the later retrieval where it holds the record and gives a value, and from
the earlier one otherwise, while citations_old and citations_new come
from each retrieval in turn. Where one retrieval holds a record more than
once, the first value it gives is used.
See also
scopus_diff_dois() to compare DOIs alone, scopus_combine() to
merge the retrievals.
Examples
# The bundled corpus carries no 'Scopus' identifiers, so its records are
# matched on their DOIs, and the eleven in each pull without one cannot be
# compared at all.
baseline <- example_records[example_records$year <= 2023, ]
later <- example_records[-1, ]
scopus_diff_records(old = baseline, new = later)
#> <scopus_record_diff> 14 added, 1 removed, 0 in conflict, 112 unchanged, 11
#> earlier and 11 later records without an identifier or a DOI not compared
#> # A tibble: 127 × 7
#> status scopus_id doi title year citations_old citations_new
#> <fct> <chr> <chr> <chr> <int> <int> <int>
#> 1 added NA 10.1002/adfm.202315… Vasc… 2024 NA 32
#> 2 added NA 10.1002/asia.202400… A Hi… 2024 NA 6
#> 3 added NA 10.1002/slct.202302… Allo… 2024 NA 2
#> 4 added NA 10.1016/j.cej.2024.… High… 2024 NA 31
#> 5 added NA 10.1016/j.diamond.2… Copp… 2024 NA 21
#> 6 added NA 10.1016/j.isci.2024… Boos… 2024 NA 8
#> 7 added NA 10.1016/j.jallcom.2… Enha… 2024 NA 5
#> 8 added NA 10.1016/j.jallcom.2… From… 2024 NA 84
#> 9 added NA 10.1016/j.jpowsour.… How … 2024 NA 14
#> 10 added NA 10.1016/j.jpowsour.… High… 2024 NA 3
#> # ℹ 117 more rows
# Two pulls of three records each, with identifiers as a live harvest
# carries them. 10.5555 is the DOI prefix reserved for tests, so none of
# these resolve. The later pull holds 10.5555/c under a new identifier,
# which makes both records under it a conflict to check, and a record from
# another source, without an identifier, that is new.
old <- data.frame(
scopus_id = c("85000000001", "85000000002", "85000000003"),
doi = c("10.5555/a", "10.5555/b", "10.5555/c"),
citations = c(5L, 3L, 8L)
)
new <- data.frame(
scopus_id = c("85000000001", "85000000033", NA),
doi = c("10.5555/a", "10.5555/c", "https://doi.org/10.5555/D"),
citations = c(9L, 10L, NA)
)
scopus_diff_records(old, new)
#> <scopus_record_diff> 1 added, 1 removed, 2 in conflict, 1 unchanged
#> # A tibble: 5 × 7
#> status scopus_id doi title year citations_old citations_new
#> <fct> <chr> <chr> <chr> <int> <int> <int>
#> 1 added NA 10.5555/D NA NA NA NA
#> 2 removed 85000000002 10.5555/b NA NA 3 NA
#> 3 conflict 85000000003 10.5555/c NA NA 8 NA
#> 4 conflict 85000000033 10.5555/c NA NA NA 10
#> 5 unchanged 85000000001 10.5555/a NA NA 5 9