2. Structure of Chemical Information

Published scientific information generally appears in various types of sources, depending on their intended role in the discovery of the information, primarily by other scientists. For example, a patent is designed to establish the first disclosure of a novel, protected technology, while a general chemistry textbook is designed to introduce core, well established chemical concepts to uninitiated students.  These information types are organized in libraries and guides around common characteristics, which can be loosely categorized according to the point they are in the timeline of knowledge, from experiment to regulation and education.2




Publication Types



first formal disclosure, usually peer reviewed

journal articles, data sets, patents



compiled, collections, structured, curated for scope, content, indexing, classification

compiled databases (literature, data)

SciFinder, Reaxys, Scopus, Web of Science, PubMed, PubChem, ChemSpider


expert synthesis

textbooks, guides, standards, review articles



not community formalized

raw data, report,  social media, chemical vendor’s documentation



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Comments 6

Audrey Bartholomew (not verified) | Wed, 09/02/2015 - 09:34
For information that would be considered "Gray" how would you go about citing it? Would you consider it common knowledge, or easily accessible and open to the public? Should information categorized as "Gray" just be avoided?

Ye Li | Wed, 09/02/2015 - 10:49

Hi Andrey,

Thanks for bringing up the interesting questions. Here are some of my thoughts on this topic. I agree that the category "Gray" is as confusing as a category named Miscellaneous. With the new and emerging means of communication and "self-publishing", the Gray literature fields are even "grayer" than ever. Many of these new forms containing information very valuable and, more importantly, convenient to access for various audiences. We may be able to categorize some of them to the primary/secondary/tertiary literature (e.g. a technical report could be primary or tertiary resource) but we won't be able to do it with many of them. For example, a website like this one  is easily accessible and contains somewhat trustworthy data and information. However, it's original purpose was to test cheminformatics technology not to disseminate the information on green solvent and the attempt to articulate the provenance of the information is incomplete. So, I am not quite sure if I'd categorize it as a scholarly resource but I would also hesitate to tell students that they cannot use it at all since the information itself is helpful. In this case, the key is to let student recognize the major components missing here ( i.e. how these rankings of green solvent were determined and by who) and also recognize the needs to seek for additional resources beyond this one.

Going back to your original questions, we define the "Gray" literature as those ones "not formalized by the community". They can be easily accessible and open to the public as the example mentioned above but can also be very locked down like an expensive trade report. Although we can't define them strictly as common knowledge or scholarly resources, we cannot simply deny their usefulness and certainly cannot keep people from using them. What we can do is to help people evaluate these resources case by case and use them wisely. The community may reach a consensus on how a certain type of sources can be categorized when it's used more broadly but there will always be new types emerging for the community to figure out.

In terms of citing them, it's, again, case by case. Some existing styles like ACS Styles started to include some rules for them, such as citing some of them as a "Webpage". It's not ideal but at least it ensures people include the URL and access dates to meet the traceable requirements of citing. Citing new forms of information like Wikipedia pages as a web page may meet the traceable requirement but may not meet giving credit and lending validity requirements due to the vagueness of authorship in the first place. But the bottom line is that if people are using these resources in a deliberated and reasonable way, they should not avoid citing them. We and the research community will work together bit-by-bit to find better ways of citing and credit attribution while using them.

In all, "Gray" may not be the best container label but we always need a container for emerging resources. I often times get excited when students discuss these resource with me since that's when they would learn the true skills of evaluating and using a resource wisely instead of just looking for the affiliation of the authors to judge the validity of information.

Brandon Davis (not verified) | Fri, 09/04/2015 - 18:45

Science blogs are an important "gray" resource. Formerly, the primary way scientists could communicate with the public was by journal publications or talks. Because science reporting in popular media is generally abysmal, working scientists publishing blogs is valuable as a platform for discussion and criticism of current science topics in the news. This is a good example: https://www.sciencebasedmedicine.org . We can't be experts in every field, so it's useful to have knowledgeable experts to evaluate technical articles for the rest of us.
Is anyone familiar with any chemistry centric blogs?

Leah Rae McEwen | Thu, 09/10/2015 - 13:52
Brandon, excellent point about blogs as "gray" information sources. Blogs poignantly illustrate both the opportunities and challenges of "gray" sources and we why designate them this way in the library environment. It is a great opportunity to foster more scientific exchange, extending the value of conferences and research hallways. The greatest concern is always reliability, as discussed in this module and some other posts. It behooves any user of scientific information to consider some level of evaluation for their context and this is certainly true for "gray" sources that are not always well characterized as to intended audience, authority, accuracy, and bias. That said, there are some very interesting scientific exchanges published in blogs by well respected professionals, research labs and scientific organizations. You asked about chemistry-centric blogs, a list is maintained on the "Chemical blogspace" as a place to start: <a href="http://cb.openmolecules.net/">http://cb.openmolecules.net/</a> (currently maintained by Geoff Hutchison and the University of Pittsburgh) About two years ago, a cheminformatics colleague analyzed the appearance of blog links on these blogs as a proxy for identifying the top 5 (<a href="http://baoilleach.blogspot.com/2013/12/top-5-favourite-blogs-of-chemistry.html">http://baoilleach.blogspot.com/2013/12/top-5-favourite-blogs-of-chemistry.html</a>). The top 5 appearing then are below (the code for this analysis is on that blog, anyone want to run the updated numbers?) "In the Pipeline" (<a href="http://pipeline.corante.com">http://pipeline.corante.com</a>, Derek Lowe) "Chem-bla-ics" (<a href="http://chem-bla-ics.blogspot.com">http://chem-bla-ics.blogspot.com</a>, Egon Willighagen) "ChemBark" (<a href="http://blog.chembark.com">http://blog.chembark.com</a>, Paul Bracher) "Orp Prep Daily" (<a href="http://orgprepdaily.wordpress.com">http://orgprepdaily.wordpress.com</a>, Milkshake) "The Sceptical Chymist" (<a href="http://blogs.nature.com/thescepticalchymist">http://blogs.nature.com/thescepticalchymist</a>, Nature Chemistry) Other popular blogs are: ChemJobber (<a href="http://chemjobber.blogspot.com">http://chemjobber.blogspot.com</a>, anonymous) SafetyZone (<a href="http://cenblog.org/the-safety-zone">http://cenblog.org/the-safety-zone</a>, Chemical & Engineering News) Henry Rzepa (<a href="http://www.ch.ic.ac.uk/rzepa/blog">http://www.ch.ic.ac.uk/rzepa/blog</a>, Imperial College London) Retraction Watch (<a href="http://retractionwatch.com">http://retractionwatch.com</a>, <a href="http://retractionwatch.com/meet-the-retraction-watch-staff">http://retractionwatch.com/meet-the-retraction-watch-staff</a>)

John House (not verified) | Fri, 09/04/2015 - 21:24
I am a little curious as to how strong "gray" bibliographic entries are in the peer reviewed arena.

Robert Belford's picture
Robert Belford | Mon, 09/07/2015 - 09:33
This is an interesting "easy-read" article for your holiday, that I do not think you need a subscription to access, <a href="http://www.nature.com/news/pioneer-behind-controversial-pubpeer-site-reveals-his-identity-1.18261?WT.mc_id=TWT_NatureNews">http://www.nature.com/news/pioneer-behind-controversial-pubpeer-site-reveals-his-identity-1.18261?WT.mc_id=TWT_NatureNews</a> Cheers, Bob