Help! My committee just passed back my proposal and said my literature review was bad! I don’t understand, I read everything that I could find on the web. What do I do?
Googling in Gainsborough
Hi GIG, To paraphrase Shakespeare; There are more things in the literature, dear student,
than are returned on your screen. Here’s the dirty little secret about your favourite search engine when it comes to the scientific literature. Not everything that exists is available in digital form, and not everything that is available digitally can be found.
I’m guessing that you’re a member of the generation that has grown up with easy access to literature on the web. And, like me, you’ve used to being able to access anything you want from the comfort of your office. Some of my more learned colleagues (‘learned’ of course is a euphemism for ‘graduated prior to 1990”) speak fondly of a time when they would actually visit the library to peruse the new journals when they came in. I’m somewhat included in this crowd as I’m one of the last that had to go to the library to read the book version of Current Abstracts to find papers for essays during my undergrad. I remember when CA came out on CD it was quite a big deal, but you still had to go to the library as my University only had a site license for a few sets of discs. It all sounds quite quaint when you consider that most of us now search for and access literature in digital form via the web. In fact it is probable that there is some student out there right now who will never visit the library to get a journal article. But hey, what’s wrong with having the world at our fingertips? No more time spent in dusty stacks only to find the book you’re looking for is gone, no more having to scrounge money for the photocopier. Sounds great, right?
Well only if you’re looking for material published within your own lifetime. Almost anything published after 1998 can be found in electronic form, either from the journal itself, or a secondary source like JSTOR. Depending on the journal, articles published as long ago as the 1980s or even earlier can now be found. There a few large and well known journals such as Science and Nature that have their full run available in digital form, but these are the exceptions, not the rule. This is changing though as more as journal publishers and societies recognize the value of having their catalogues online [as I submit this in February 2009 the Entomological Society of America just announced their full catalogue is available online, as soon will be The Canadian Entomologist]. However it is still the case in 2009 that older papers published in smaller and more field-specific journals are not available in digital form
But let’s assume for a minute that at some point in the near future everything will be made available on the web. Will we still be able to find it?
When running an internet query we all follow the same pattern. Think up some key words, punch them into that little box and hope for the best. We hope that a) we’ve picked the right search terms and b) those terms can be found in the search engine’s database. For modern digital papers in PDF format the database is quite large because the software can scan the title, the abstract, the key words and the body of an article. Having access to this much material maximizes the probability of your search terms being found. If you’re in luck your search engine also possess the ability to suggest similar terms and help you refine your search. However, searching becomes harder with older papers because anything from the mid 1970’s till the early 1990’s may only be indexed by the title and abstract, works older than that may only be indexed by the title. And that’s only assuming some poor soul has been paid to do the unfortunate job of keying in all those old abstract books that I used to have to search through as an undergraduate. Moreover, this situation is unlikely to change even as more old papers are scanned and put on the web as its unlikely that article text will be made searchable (Optical character recognition is still hard and expensive). So unless you’re a search engine ‘ninja’ or very lucky it’s you’re probably not going to find everything published on your particular organism by just relying on a simple web search.
Oh, and just to make it interesting, up till know I’ve only been considering the peer-reviewed literature. I haven’t even talked about the ‘grey’ literature put out by government agencies which are rarely indexed anywhere on the web. These often contain an abundance of valuable technical and methodological information. We also haven’t discussed the technological limitations of the various searching software. Free, public search engines (Google, Yahoo etc…) are only able to return that material that is posted to the ‘searchable’ web; however lots of scientific material may be hidden in protected sites that aren’t indexed. Moreover the ‘filter’ on these sites can be fairly coarse, and while it may return good leads to papers, you’ll also get a lot of trash that needs to be filtered by you. When we consider the more specific literature database searching tools (e.g, Web of Science) your searching success may also hinge upon which databases your university or agency subscribes too. For instance, the organization I belong to only purchases access to the last 5-10 years of published works. Other libraries may only buy certain databases that reflect the perceived research strengths of their university. Lastly not all journals are catalogued by all literature databases, so even current material may not show up in your searches.
So what’s a student to do?
- Learn to search efficiently and effectively. Check out your library and see if they offer workshops in searching the scientific literature. Spending the time to learn some good strategies will save you time and headache later on. At the same time get to know your library and how to navigate the stacks so you can find those old journals when the time comes.
- Be aware of where you’re searching. The next time you log into your literature search tool read the description of the database you’re searching in. What time period does it cover? What journals are indexed? Can you add other databases (or remove irrelevant ones) to focus your search.
- Read everything. As you go through papers, note which articles are being cited. Are these papers (especially the older one’s) showing up when you search? If not it may be time to refine your search terms and for a trip to the library to pull some old papers.
- If all else fails and you’re still looking for old material the best place to go is an old entomologist. If you know of a researcher who has worked on your system in the past its worth asking if you can have a look though their files. However don’t use this as a shortcut for your own literature review, get an appreciation of what’s in the literature first, and then seek out someone with a bigger library.
Well GIG, I hope that helps. It is likely that as more and more material becomes available in digital form we will be able to search and access the bulk of the scientific literature online. However we’re not there yet, until that time we still need to work on those old search skills.
This column originally appeared in the March 2009 edition of The Bulletin of the Entomological Society of Canada