Introduction to information skills 2

Transcription

1 Library & Archives Service +44 (0) Introduction to information skills 2 Effective literature searching in Google and PubMed Aims and objectives Defining your search topic Asking questions Identifying concepts Types of information Choose the resources to search Search engines Bibliographic databases Choose your search terms Compiling and running your search Truncation Boolean operators Running your search on Google Evaluating your results Using PubMed Find the full-text Finding full-text via the Library Catalogue Finding full-text via the SFX button Manage your information Getting more help I:\UserTraining\ \Foundation\Foundation 2 Material\Foundation 2 Materials UPDATED\Foundation2_handout docx 26 August 2014

2 Aims and objectives This handout has been designed for you to keep and refer to during your studies. It accompanies a class that provided an introduction to effective literature searching. The 6 steps to an effective literature search are: 1. Scope your search 2. Choose the resources to search 3. Choose your search terms 4. Compile your search strategy and run your search 5. Find the full-text 6. Manage your information This handout describes how to use these six steps to search Google and PubMed for information. Working through these steps will ensure that your searching is effective and efficient. You are more likely to find relevant information with less effort. 1 Defining your search topic The first stage of any search should be to define what it is you are looking for. This might sound obvious, but it is part of the search process which people commonly do not put enough thought into. You are searching a massive body of published literature; the PubMed database alone contains citations for over 24 million journal articles. Unless you are very specific about what it is you want to find it will be difficult and frustrating to extract anything useful. 1.1 Asking questions The best way to define your search topic is to ask questions. Turn your topic into a question that you need the literature to answer. Then ask more questions about the type of information you want to find to answer this question. This will make your search more specific and relevant. I want to find evidence on the relationship between outbreaks of dengue and the weather in South America. Question I need to answer: Can dengue fever outbreaks in South America be predicted by the weather? 1.2 Identifying concepts Most searching tools will not work very well if you just type in your question. You need to search logically by splitting your question into concepts; these are the building blocks of your search. Look at your question and identify which subject areas each item must address in order to answer your question. If you have more than three subject areas or concepts, your question is probably too complicated you won t find many papers that address all of your subjects together. 2

3 Question I need to answer: Can dengue fever outbreaks in South America be predicted by the weather? Concepts: dengue fever, weather, South America 1.3 Types of information You will also need to think about what type of information you need to answer your question. There are a number of different types of information available, it is helpful to have a good idea of the differences between them when searching. This will help you when you come to draw conclusions from the information you find. Some of the more common terms you may come across include: Primary research This is research which collects original data such as a controlled trial, cohort study or questionnaire. Primary research generally looks at a very specific topic. Secondary research Secondary research uses the data obtained in primary research to generate new data and conclusions. There is no collecting of original data, instead the researcher is reliant on the data collected by others. Secondary research includes publications like systematic reviews. Peer-reviewed journal articles The vast majority of reputable academic journals are peer-reviewed. This is a type of quality control. Prior to publication, each article is reviewed by other experts in the field. Authors may have to edit their manuscript or explain their reasoning as a result of the peer-review process. Papers will be rejected for publication if they fail. Grey literature This is a term used to describe information which is not published commercially or is otherwise hard to find. This includes items such as government reports, NGO reports, theses, technical reports, white papers etc. Open access An open access journal article is one which is freely available to download online. Sometimes whole journals are published using this model, sometimes only selected articles are available on open access while the rest of the journal is available for a fee. Licensed information The vast majority of academic information is only available to you for a fee. The institution can purchase access for all current staff and students, or individuals can purchase access to specific titles or articles. The license often restricts who can access the information and what can be done with it. Each of these different types of information are available from different places. Knowing what type of information you are looking for makes the choice of resource to search much easier. 3

4 Question I need to answer: Can dengue fever outbreaks in South America be predicted by the weather? Type of information required: Journal articles and research reports 2 Choose the resources to search Now we have completed step 1 we have a clear idea of what we want to find. The next step is to decide where to go to find that information. Today we will be looking at two types of search resource; a search engine and a bibliographic database. 2.1 Search engines Google has been the most widely used search engine for several years now. It is excellent at finding grey literature. This is material that is not formally published in a book or journal such as NGO reports, official documents, statistics, and images. You should not use Google, or Google Scholar, to find high quality academic research. This is because: Google does not search every website in the world. There is a significant section of the internet called the invisible web which search engines like Google are unable to search. This often includes the contents of bibliographic databases. When Google does a search, it does not search the live internet. It searches a copy that can be six months out of date, meaning you miss the most recent information. Google is a business. It is there to make money. Businesses can pay to get their content near the top of the results. This means that the results on the first page are not always the best quality or the most relevant. 2.2 Bibliographic databases If you are looking for academic information, particularly journal articles, then you should use a bibliographic database. Bibliographic databases contain details of millions of journal articles, published in thousands of journal titles. The School subscribes to a broad range of databases, each containing a different type of information or subject area. There is not one database which covers all journals written on all subjects. Which databases you search will depend on the subject you are trying to find information on. The full listing of databases available at LSHTM can be found at Today we will be searching PubMed, as it has wide coverage of health topics and is freely available to all. This means that you can continue to use it when you have finished your studies at the School. 4

5 3 Choose your search terms The third step is to choose the terms we are going to use in our search. We need to identify terms that describe each of the concepts we came up with in step 1. It is important to remember that a search resource can t think like a person can. It especially can t appreciate nuance in language. If I type in weather, the database will not know I also want to find papers that discuss climate or seasonality or rainfall etc. You have to think of all the different ways each concept could be described and include these in your search; otherwise you may miss important papers. You should consider: Differences in spelling e.g. organisation, organization Different endings to words e.g. injured, injury, injuries Diseases and disease vectors e.g. malaria, plasmodium Abbreviations e.g. AIDS, acquired immunodeficiency syndrome The concepts I came up with in section 1.2 are: dengue, weather, South America I now need to think of the synonyms and alternative words which the author could have used to describe the two concepts. Here are some synonyms that I ve thought of for two of the concepts. dengue aedes flavivirus weather climate/climactic temperature rainfall/rain season/seasonality To get the most comprehensive set of results, and ensure that we haven t missed anything important, we need to include all the synonyms we can think of in our search. 4 Compiling and running your search Now you have a list of synonyms for each concept, you can use these to put your search together. There are two search techniques you can use to help you: truncation and Boolean operators. 4.1 Truncation As well as using different words, authors use different forms of words. The databases are not clever enough to know that if you are interested in articles with the word injury you are also interested in articles with the words injured and injuries as well. 5

6 Most databases allow you to specify the beginning or root of the word and leave it up to the database to add all the alternative endings. The most common way to do this is to add an asterisk to the end of the word root. To find different endings to the word injury, add an asterisk to the end of the root of the word injur* 4.2 Boolean operators We use Boolean operators to combine our search terms together correctly. OR is used when you want to find items containing ANY of your terms. It is typically used to join synonyms for the same concept. weather OR rainfall OR temperature AND is used when you want to find items containing all of your terms. It is typically used to join different concepts together. dengue AND weather You can use brackets to make sure the system does your search in the correct order. Put all of your synonyms for your first subject in one set of brackets and all of your synonyms for the second subject in another set of brackets. Link them together with AND. (dengue OR aedes) AND (weather OR rainfall or temperature) Putting it all together my search will look like this: (dengue OR aedes OR flavivirus) AND (weather OR climate* OR temperature* OR rain* OR season*) AND (South America OR Colombia OR Venezuela OR Guyana OR Suriname OR French Guiana OR Ecuador OR Peru OR Brazil OR Bolivia OR Paraguay OR Chile OR Argentina OR Uruguay) 6

7 4.3 Running your search on Google Enter phrases in quote marks, eg south america. Enter Boolean operators in UPPERCASE. Google automatically truncates your terms so you should not use an asterisk. Print and refer to the cheat sheet at This gives you lots of shortcuts to Google search features. My search looked like this: (dengue OR aedes OR flavivirus) AND (weather OR climate OR temperature OR rain OR season) AND ( south america OR colombia OR venezuela OR guyana OR suriname OR French Guiana OR ecuador OR peru OR bolivia OR paraguay OR brazil OR uruguay OR chile OR argentina) 7

8 4.4 Evaluating your results You will have found that the results we got from Google came from a variety of sources. Whenever you use a search engine to find information, you should always ask yourself these questions: WHO provided the information and why? Is the author a doctor, nurse, health organisation, university, respected expert, commercial company or interested individual? Are they qualified or reputable? Are they representing themselves or an organisation? Are they using selected facts to sell an ideology or medical viewpoint? Is the information backed up with references? WHEN was the information published? Is there a publication date? Is there a copyright notice? If you are looking at health statistics, how far back does the data go? Is the coverage period clear? How frequently is the site updated? Do the links work? Is a Webmaster or contact address available? How established is this resource - will it still be there next week? WHERE is the information held and where did it come from? Is the server commercial, educational or organisational? Is it an individual's page on a University Web site? Is the validity of the information compromised by the aims of the host organisation? Is the information from the UK, Asia or America? Does this affect the validity of the information? 4.5 Using PubMed We can enter our terms into PubMed in the same way as we did in Google. PubMed does not automatically truncate so this time we should include the asterisk where appropriate. My search looked like this: (dengue OR aedes OR flavivirus) AND (weather OR climat* OR temperature* OR rain* OR season*) AND ( south america OR colombia OR venezuela OR guyana OR suriname OR french Guyana OR ecuador OR peru OR bolivia OR paraguay OR brazil OR uruguay OR chile OR argentina) 8

9 Results are displayed with the most recently added items first. So you will see the most recent research first. Click on the title to view more information about the item. Often you will find an abstract or summary of the paper. PubMed also lists details of other articles which it thinks are similar to the one you re viewing (Related citations in PubMed). Click the title to view details of that article. In PubMed, you can save or details of the articles you want. Just mark each article you want the details for by ticking the box next to it then choose where you want to send the information from the Send To drop-down menu. 5 Find the full-text Most bibliographic databases will only provide an abstract or summary of the paper. You will be expected to read the entire paper for your studies. 5.1 Finding full-text via the Library Catalogue Links to all of our books and journals are available from the Library Catalogue. If the item is available electronically there will be a link to the full text. You can access the catalogue via the link from the Resources page on the Library s website: Finding full-text via the SFX button The SFX button is available on most of the School s database subscriptions and links you directly from your results to the full text of the article (if available). When you click the SFX button, the SFX window will appear. 9

10 The citation of the item appears at the top of the menu. If electronic full-text is available, a link to it appears under the Full Text section. Click the red GO button to go directly to the full text. Sometimes, due to duplication in deals provided by publishers, the same journal article is listed more than once click either GO button. If the full-text is not available, the SFX window will tell you. You can then use the Holdings information options to see if the item is available in print anywhere. Remember to check the LSHTM Library catalogue some journals are not available electronically but are available in print. 6 Manage your information You must keep details of all of the items you find in order to cite them correctly in your assignments. You must do this in order to avoid allegations of plagiarism. The handout from the first session in the Library provides more information on citing references. PubMed allows you to send details of all of your results to a file or to your address. See the end of section 4.5 for details. Google does not have this facility - it is up to you to keep sufficient details of each website you visit to create a valid reference. This includes the author s name (if an author is provided), the year the site was published or last updated, the title of the page, the web address and the date you accessed it. As webpages are updated all the time, the date of access is very important the information may not be there in a few months time. 10

11 There are computer software programs which help you to keep track of your references. The School supports EndNote which is installed on all School computers. Training on EndNote is provided by IT Services ( 7 Getting more help There are a range of help resources, including video guides, on the Library web pages ( You can also contact us: the Library s contact details are on the front of this handout. 11