Upon acceptance for publication in different journals following peer
review, all journal articles had the same title of the selected
preprints deposited at ChemRxiv, and at Preprints. Only in the case of
preprint 8 first posted at Preprints, the title of the
corresponding journal article was shorter.
The abstracts of the preprints published in ChemRxiv and the
corresponding journal articles were the same in three out of five cases.
The journal article deriving from preprint 2 specified that the
article derived from interaction with the members of the Association of
Environmental Engineering and Science Professors in a workshop organized
at the 2017 association conference. The journal article published after
preprint 4 includes two minor writing style changes.
The abstract of the preprints published in Preprints and the final
published journal articles was the same in two out of five cases,
specifically for preprints 6 and 9 and the
corresponding journal articles. In the case of preprint 10 the
abstract of the journal article [15] was significantly shorter than
that in the preprint. The abstract of the final published article
[16] is longer and slightly more informative than that of preprint7 , similarly to what happens for the abstract of the journal
article [17] when compared to that of preprint 8 .
Little or no differences were found between the texts of the final
journal articles and the preprints published in ChemRxiv months or weeks
before. Preprint 1 even used the template of the subscription
journal in which it was eventually published five months after the
preprint. Interestingly, the study made freely accessible as preprint
includes on each page the sentence “Submitted manuscript:
confidential” [18]. Preprint 2 makes use of the template
of the subscription journal in which it was published two months after
the preprint as open access (OA), with a Table (Table 1) resulting of
even higher readability (using colors) in the preprint [19] than in
the peer reviewed article. In the case of preprint 3 , the final
article published four months after the preprint in a OA journal
includes three more references and slightly longer conclusions [20].
Preprints 4 and 5 do not use a journal template, but
their content is virtually the same of the final published articles.
Preprint 4 does not include page numbers [21] but embeds
high resolution colored Figures and Schemes. Downloading the preprint
from ChemRxiv, users would also download the Table of Contents graphics
and the same 470-page long Supporting Information section found four
months later in the final published article. When compared to the text
of preprint 5 , the peer reviewed article published 16 days
after the preprint [22], includes at the end of the article a brief
“Post preprint addendum”, and five more references.
The latter preprint was uploaded, approved and published on the same day
(October 17, 2018). The day before Angewandte Chemie published a
manuscript [23] of a Swiss-German team reporting the invention of a
similar method to obtain the molecular structure of microcrystalline
molecular compounds via electron diffraction. The manuscript had been
received by the journal editorial office on October 2, 2018.
Larger, though still not significant differences were noted between the
selected preprints deposited at Preprints and the published journal
articles. When compared to the text of preprint 6 , the final
published article illustrates concepts through new research in a quickly
developing field of chemistry published in the literature in the 20
months between the publication of the preprint and that of the journal
article [24]. The final published article was virtually identical to
preprint 7 , unless for a minor mistake in the sequential order
of the Figures in the preprint that was corrected in the journal article
[16].
When compared to preprint 8 , the final published article
[17] had a substantially higher number of references (22 vs.17) and a longer and more informative conclusions section. In comparison
to preprint 9 , the final published article [25] includes
five new Schemes and one new Figure. The experimental section and the
conclusions were identical.
The largest differences in the present analysis were noted between
preprint 10 and the corresponding journal article [15]. The
latter embeds a more succinct presentation, with only four Tables in the
journal article vs. six in the preprint. Furthermore, the journal
article includes both an elegant and highly explanatory image (Figure 1)
displaying the experimental design and a new Figure (Figure 2) showing
electron microscopic pictures of treated and non-treated orange peels.
Both were absent in the preprint. Finally, the journal articles includes
a richer conclusion section.
Published between 2018 and 2020, all selected preprints but one had more
than 100 reads (unique views) by October 23, 2020. In general, the
number of views was significantly higher for preprints published in
ChemRxiv. For comparison, the most viewed preprint at Preprints among
those selected herein had 928 views whereas the most viewed preprint at
ChemRxiv had 60,352 views. In general, by the same date the most viewed
preprint published by Preprints had 5,369 views (See at the URL:
www.preprints.org/subject/browse/chemistry?filter=most_viewed).
The high number of reads for preprints posted at ChemRxiv was noted
since the early days of the preprint server, when a manager of the OA
programme of the ACS was “pleasantly surprised” [26] by the fact
that by June 12, 2018, the 400 preprints posted had about 378,000
downloads/views. The trend continued, and two years later the editor of
the online publishing platform remarked how preprints at ChemRxiv had
been accessed “more than 10 million times, with upwards of 250,000
visitors to the site each day” [27].
Outlook and Perspective
Though exploratory and statistically non-significant, the analysis of 10
preprints selected from ChemRxiv and Preprints repositories and the
respective published journal articles offers preliminary evidence that
also in chemistry little difference exists between preprints and their
final versions published as peer reviewed articles. Following studies
and even experiments with reviewers involving the peer review process
when editor of a prestigious medical journal, Smith in 2006 concluded
that peer review “is a flawed process, full of easily identified
defects with little evidence that it works” [28].
Chemistry scholars massively read preprints, with close to 13.5 million
views for about 6,500 preprints posted on ChemRxiv by late October 2020.
Furthermore, preprints deposited at ChemRxiv that had been cited 430
times in 2019 and 85 times in 2018, in 2020 started to be cited at fast
rate with close to 1,050 citations in the first 10 months of
2020 (Source: Scopus, October 2020). By reading preprints,
research chemists learn new methods and outcomes of relevance to their
research several months ahead of time. Even in 2013, when virtually all
chemistry journals were published on the internet, the average
publication time (submitted to published time) for chemistry manuscripts
was 9 months (and 4.5 months for submitted to accepted) [29].
Rather than striving to publish their work in journals of high journal
impact factor, young chemistry researchers should be aware that the JIF
is a poor statistical indicator imposed by a very small number of highly
cited papers for which most papers published in high impact factor
journals actually get fewer citations than indicated by the JIF
[30]. In brief, by making their work freely and immediately
accessible on the internet as preprints, chemistry scholars will rapidly
reap the benefits of open science already demonstrated in closely
related disciplines (life sciences and physics) in terms of enhanced
citations, media attention, collaborations, job and funding
opportunities [31]. Research chemists posting their research
manuscripts on preprint servers, for instance, immediately enhance the
visibility of their work. Also for chemistry scholars, the accurate
measurement and wise evaluation of scientific output promoted by
numerous scholars subscribing to the San Francisco Declaration on
Research Assessment [32], today includes numerous other indicators
beyond citations collectively called alternative metrics
(“altmetrics”, for which even an international OA journal was
established in 2018, Journal of Altmetrics). The number
of reads (views) and downloads of each preprint, for example, is a
common feature for both Preprints and ChemRxiv preprint servers, and a
clear indication of interest of the scholarly community.
Table 4 . Average journal price by discipline in 2020. Top five
ranking. [Source: Library Journal Periodicals Price Survey, 2020].