Special Review Article Searching web based medical information

Ibrahim Mansoor, MBBS.

ABSTRACT

Searching for references is part of everyday life in medicine. Since the arrival of the Internet, it has provided great promise for clinicians because of it’s ability to access and consolidate large amounts of knowledge and information quickly and easily. But because of the overload of the huge amounts of information, searching for particular information has now become a tedious task, which is a lso very time-consuming and frustrating. This article describes effective ways, tips, tools, detailed search techniques and strategies for searching medical information. It also lists some useful resource and database sites that can provide a lot of help for seeking accurate information.

Keywords: Internet, web-based medical information, search engines. Saudi Med J 2001; Vol. 22 (9): 749-756

he Internet is a massive collection of computer do you find what you are looking for? This paper T networks that connect millions of computers, deals with this problem of finding particular medical people, software programs, databases and files. information on the Internet. The paper presents a Though it is comprised of various sections from detailed discussion of different types of search tools, newsgroups through email services, by far, the most with the main features of these major tools, there popular and fastest growing is the strategies, techniques and tips for the users on how to (WWW or just "Web"), cited as most important by interact with these tools, available on the Internet. two-thirds of the users, followed by electronic mail.1,2 Search tools on the web. Finding information on The Web has accelerated the growth of the Internet the Web may be difficult, but it's not impossible. As by giving it an easy to use, point and click, graphical an alternate to a central catalogue the Web offers a interface and it contains a universe of network choice of dozens of different Search Tools, each with accessible information. In February 1999, the Web its own database, command language, search contained approximately 800 million pages of capabilities, and method of displaying results. The information, increased up from 320 million in Search Tools, also known as Search Services, find December 1997.3,4 Adding to this, the fact that the documents matching your interests. Each search tool Web lacks the bibliographic controls standards. operates on its database of Uniform Source Locator There is no equivalent to the ISBN to uniquely (), texts and descriptions that point to the actual identify a document; no standard system of documents on the Web.2,7 An important point to cataloguing or classification; and there is no central clarify is that whenever you search with the help of a catalogue that point to all of the Web's holdings. In search tool, you actually view data extracted from the fact, many, if not most, Web documents lack even database of this search tool and not from the whole the name of the author and the date of publication.5,6 Web. Since none of these search tool databases Now with 800 million publicly available documents include the whole Web, you get different results from — an amount that is doubling in size every 6 to 12 different search tools. All search tools provide the months, the Internet has become a vast, global search results as list of Web documents with storehouse of information. The only problem is: how hypertext links; which when clicked takes us away to

From the Department of Histopathology, King AbdulAziz University Hospital, Jeddah, Kingdom of Saudi Arabia. Address correspondence and reprint request to: Dr. Ibrahim Mansoor, /o Mansoor Ali, PO Box 1432, Jeddah 21431, Kingdom of Saudi Arabia. Fax. +966 (02) 661 3164. Email: [email protected] 749 Searching web-based medical information ... Mansoor that particular Web document from the search tool. most effective for finding general information on The search tools on the Web fall into 2 main popular or scholarly subjects. If you are looking for categories: Subject Directories, which rely heavily on something specific, use a .26 It is also the human element as part of their indexing strategy, important to remember that no one has categorized and Search Engines, which keep human/data the entire web. There are millions of web pages on interaction to a bare minimum. Both use software the Web and it is simply impossible to organize robots called "Spiders" that crawl the Web, everything, especially at the rate at which the Web is newsgroups, and gopher, file transfer protocol (FTP) expanding. Examples of subject directories include: and wide area information servers (WAIS) sites, About.com [http://www. About.com], Look Smart extracting URLs (addresses) and keywords to add to [http://www. .com], WebCrawler [http:// the search tool's database. Both of these search tools www..com], Yahoo [http:// have benefits and drawbacks, depending on what you www.yahoo.com]. are willing to sacrifice.2,7-9 New MetaCrawlers have Search engines.7-26 The Search Engines are very now emerged, as the best way for querying multiple different from directories. While humans organize engines at once. They do not maintain their one and catalog subject directories, search engines rely on database; instead, they act as middle agents and pass computer programs called spiders or robots to crawl on your query to many major search engines.7-26 the Web from one link to another, and log the words Subject directories. The subject directories are on each page into its database. When any keyword hierarchically organized indexes of subject categories related to a topic is typed into a search box, the that allow the Web searcher to browse through lists search engine scans its database and returns a file of Web sites by subject in search of relevant with links to containing the word or words information. They are often called subject "trees" specified. It is important to note that when you are because they start with a few main categories and using a search engine you are not searching the then branch out into subcategories, topics, and Internet "live", as it exists at this very moment. subtopics. For example, if you are looking for any Rather, you are searching a fixed database that has medical information related to "Saudi Arabia" at been compiled some time previous to your search.18,26 Yahoo, select "regional" at the top level, then While all search engines are intended to perform the "countries" at the next level, than "Saudi Arabia" at same task, each perform it in a different way, which the 3rd level, and "medical information" at the 4th leads to sometimes amazingly different results. level. This hierarchy could be represented as: Factors that influence results include the size of the regional / countries / Saudi Arabia / medical database, the frequency of updating, and the search information.27 The subject directories, simply called capabilities. Search engines also differ in their search directories, are compiled and maintained by humans, speed, the design of the search interface, the way in and therefore you can often find it a good starting which they display results, and the amount of help point for your topic. They are also useful for finding they offer. In most cases, search engines are best information on a topic when you don't have a precise used to locate a specific piece of information, such as idea of what you need. Furthermore, because their a known document, an image, or a computer maintenance includes human intervention, they program, rather than a general subject. Examples of greatly reduce the probability of retrieving results out search engines include:26 MSN Search [http:// of context. As the subject directories are categorized, search.msn.com/], AltaVista [http://www.altavista. they give links to the top levels or main pages of a com/], Ask Jeeves [http://www.askjeeves.com/], Web site rather than to individual pages and they [http://www.excite.com/], Fast Search cover only a small fraction of the pages available on [http://www.fast.no/sitesearch.html], Google the Web. They are best suited for searching [http://www.google.com/], HotBot [http://www. information about a general subject for example, .com/], Infoseek [http://www.infoseek.com/], information required about medical fields such as , [http://www.lycos.com/], Northern Light pathology, ophthalmology etc or about main organs [http://www.northernlight.com/]. like breast, kidney etc, rather than for a deeper and Meta search engines. The growth in the number more specific piece of information. Many large of search engines has led to the creation of "meta" directories also provide an option to search by a search engines, often referred to as multi-threaded or keyword, which takes us directly to a specific topic multi-search engines. These search engines allow a and usually eliminates the need to work through user to search the databases of several major search numerous levels of topics and subtopics. The engines in parallel (at the same time). They do not directories rely on the judgment and expertise of the crawl the Web or maintain a database of Web pages. people compiling them and here it is obvious that Instead, they act as a middle agent, passing on the subject experts would have different and more query to the major engines like AltaVista, Excite, professional selection criteria than a hobbyist or a Lycos, WebCrawler, Yahoo and HotBot, and then casual user.26 Because directories cover only a small returning the results.23-28 The meta-search engines fraction of the pages available on the Web they are work best with simple searches. They do not offer the

750 Saudi Med J 2001; Vol. 22 (9) Searching web-based medical information ... Mansoor same level of control over the search interface and Ask Jeeves [http://www.askjeeves.com]. Ask search logic, as do individual search engines. They Jeeves deals with plain English queries and it is good vary in ability to interpret complex searches and for when you don't want to deal with complicated query the most part, they strip the advanced search syntax syntax and overwhelmingly large result sets. It has a and logic from your queries when they submit them knowledge base that contains common questions and to the search engines. This is because the interface of links to more than 7 million answers. It compares the meta-search engine must be programmed to your query with templates within its knowledge base interpret your search syntax for each and every and then returns questions that most closely match search engine it queries. Most of the meta-search yours with links to the answers. So Ask Jeeves is engines are very fast. Some of them include such good mainly for general common topics. useful features as the ability to select which search Excite [http://www.excite.com]. Excite uses a engines to include, and the ability to modify results. combination of text and subject indices to search Some of the meta-search engines can also sort results either by keyword or by concept. Concept searches by site, by type of resource, or by domain. Because find documents related to the idea of your search, and the major search engines often produce very different not just documents explicitly containing the search results, meta-search engines provide a quick way to terms you enter. Excite offers easy searching determine which engines are retrieving the best techniques for beginning to intermediate users. Its match for your information needs. Popular meta- advance searching features from medical information search engines include: [http:// is not as powerful as Northern Light or HotBot. www.dogpile.com], Inference Find [http:// FAST Search [http://www.fast.no/ www.infind.com], Internet Sleuth [http:// sitesearch.html]. Fast Search has one of the largest www.Isleuth.com], Metacrawler [http:// database collections and it catalogs 200 million www..com], ProFusion [http:// unique URLs, more than any other search engine. www.profusion.com], Savvy Search [http:// Fast is quick and efficient and it works best with www.Savvysearch.com]. simple focused searches. Choosing a search tool.21 In order to take Google [http://google.stanford.edu]. Google is an advantage of the resources offered by the Web ongoing research project at Stanford University. It is without spending many fruitless hours, it is necessary strong competition for Yahoo if you're looking for to familiarize yourself with the search tools. Every just a few sites to answer your question. It has the search tool on the Web is different. They vary in ability for searching through its vast quantity of features, size, accuracy and flexibility. The most information and finding the specific piece you're important features in selecting a search tool are those looking for. It is very effective for searching specific which allow you to refine or focus your search when medical information. What gives Yahoo the edge is you need to. The following is an overview of main its excellent directory structure, which allows for features of major search tools:7-27 unexpected browsing of related subject categories. About.com [http:about.com]. About.com (formerly But Google's search capabilities are limited because The Mining Co.) is a subject directory and people it only offers simple keyword searching but it is very called Guides pick the sites for any particular topic. helpful at returning relevant results. The names, faces, and qualifications of these people HotBot [http://www.hotbot.com]. HotBot is a are also prominently displayed on the site. The valuable search tool for both experienced and novice About.com is not as comprehensive as Yahoo, but searchers. It offers a sophisticated interface with a you may obtain better results by searching its topics vast array of options. A unique feature of HotBot is if you are looking for general information on a the engine's ability to save a search, so that you can subject, rather than trying to find the answer to a come back later to continue without going through all specific question. the documents again. The large Web index, advanced Alta Vista [http://www.altavista.com]. Alta Vista search capabilities, and graphical query-building aids has one of the largest database and extensive search make it a good choice for detailed queries. In options and these features make it a favorite for addition to supporting boolean syntax, wild cards, power searching. It is a good search engine for and case-sensitive searching. HotBot also offers a intermediate to experienced user but its interface is variety of filtering options, including media type and less user-friendly than the comparable search page depth. engines. AltaVista handles simple search terms very Infoseek [http://www. infoseek. Com], LookSmart well and it has a powerful advanced searching feature [http://www.looksmart.com] and Lycos [http:// for complex medical terms. The advanced searching www.lycos.com]. These 3 are average search engines feature can also be used to improve simple search and do not have much to distinguish then from their results. AltaVista is very strong if your search needs many competitors. Their virtues are speed and ease are very focused and it is the best site for specialized of use and its defects are a lack of sophistication. The medical needs. It can also search in a foreign advanced searches form of Infoseek do a better job of language. finding useful information than the simple search

Saudi Med J 2001; Vol. 22 (9) 751 Searching web-based medical information ... Mansoor does. None of these have features or tools compelling smaller but more focused results set with better enough to give them an edge over Yahoo. quality returns.35 MSN Search [http://searchmsn.com]. MSN How to select a search tool.27 The key to Search, like HotBot, uses search engine but determining which tools to select depends on what it has fewer search options. Advanced search options type of information you're looking for. You should require no special syntax and are entered using a use a site like Yahoo! for broad, topic-level queries, series of pull-down menus with boolean, date, where you are looking just for the best site on the domain, language, and media search options.23 Web on a subject. When you're looking for a very Northern Light [http://www.northernlight.com]. specific piece of information, you may want to use a Northern Light is both an Internet search engine and search site like Northern Light, HotBot, or Alta a fee-based database service. It has powerful search Vista, which provides you with more unbridled capabilities and an innovative way of sorting results. power. Popularity engines like Google and DirectHit Combined with its fee-based content, these features (integrated into HotBot, Looksmart, and Lycos) can give it a strong edge over its competitors for be real time-savers if you're looking for a very research. Northern Light's uncluttered interface hides popular term and you just want one or 2 sites to a wealth of powerful features, including support for answer your query. You may also want to try a Boolean syntax, nested queries, wild cards, and specialized search site that has assembled a narrowly truncation. The Power Search page offers additional focused database on a particular topic. refinements such as field searching and the ability to How to use search tools. It can sometimes be very limit a search by date, language, or domain. time consuming and a frustrating effort to locate Northern Light's fee-based database offers full text of information on a particular topic. This is in part due over 5,400 journals, reviews, books, magazines, news to the factors listed below, which make it difficult to wires, and other sources, which you can search find relevant information. 1) The sheer size of the separately or in conjunction with the Web. Thus, Web, currently estimated to contain over 800 million with one search command, you can search the Web documents.1 2) The search engine’s web coverage is as well as the text of thousands of popular, scholarly, on the downside. Due to explosive growth in the and specialized print resources. This is one of the number of online documents, the total search engine very best sites for seeking medical information coverage has fallen from 60% in December 1997 to effectively and for reference collection.29-34 42% in February 1998, with no single engine Snap [http://www.snap.com]. Snap is a subject indexing more then 16% of the web.2-4 3) All search directory but the searching is also well implemented, tools are not created equal. Some tools index only well documented, and well integrated into the site. Web page titles and URLs, others index the full text Browsing through Snap's categories is generally of the pages. Some of the databases are automatically more effective for broad, topical searches. For highly generated; others rely on individuals to contribute focused queries, Snap's search interface boasts URLs. Some allow Boolean searching, others use power, precision, and ease of use.23 keywords only.5 4) None of the search tools claim to [http://www.webcrawler.com]. be able to pinpoint exact resources.2 It is clear from WebCrawler is a simple search alternative for less these factors that the features, capabilities, and the experienced users and it is part of Excite's network. It contents of a search tool play an important role in offers a "Natural Language Search" feature that searching information on the Web. If you know the allows you to enter a search like "highest mountain in features and use of various search tools, you can find the world". It is effective at simple searches but didn't information faster and easier. really compare with some of its simple search Tips for using search tools. In most cases, an counterparts such as Google. It also does not handle effective search strategy, the correct use of Boolean punctuation well, even with phrase searching. logic, and familiarity with the features of each of the WebCrawler does support Boolean operators to help search tools will lead to satisfactory results. The you with advanced searches, but the site has no following search tips apply to one or more of the advanced search page; you have to go to the help search tools discussed earlier:9-28 1. The more search pages and learn the syntax. keywords you use, the more accurate your search will Yahoo! [http://www.yahoo.com]. Yahoo! is the become; 2. Good keyword selection is as much number-one Internet search site and is good for both about excluding the irrelevant as it is about including novice and experienced users. With a collection of the relevant. Being as specific as possible will yield more than 500.000 handpicked sites classified into the best results; 3. Since no single search tool will more than 25,000 categories. Yahoo! makes an suit all your needs, use at least 2 or 3 different tools excellent starting point for both browsing and regularly. Learn the features and the capabilities of searching. Yahoo is a great place to search, because these tools so that you can use them effectively; 4. It it has the most comprehensive and well-organized is wise to check more than one search tool for any directory. Because humans add and categorize the topic, because search results vary widely from one to pages in Yahoo!'s database, a search always yields a another; 5. If you are more interested in broad,

752 Saudi Med J 2001; Vol. 22 (9) Searching web-based medical information ... Mansoor general information, the first place to go is to a State what you want to find. In one or 2 Subject Directory. If you are after narrow, specific sentences, state what you want to find on the Internet. information, a Web Search Engine is probably a For example: 1. What are the recent findings about better choice; 6. Most of the search engines return new drug therapy discovered for cancer treatment? results with confidence or relevancy rankings. In 2. I want to find information on popular methods of other words, they list the hits according to how losing weight. Using the information "contained" in closely they think the results match the query. these statements, you can see how an effective query Consequently, it is often not necessary to browse can be built by following the guidelines. through more than the first few pages of results, even Identify keywords. Break down the topic into key when the total results number in the thousands; 7. concepts and underline the main concepts in the Many search engines provide 2 different interfaces statement. What are the recent findings about new for searching the Internet; the Basic and the drug therapy discovered for cancer treatment? Advanced. The Basic or Simple search interface is a Use nouns and objects as query keywords. When good place to start your search but it lacks many of conducting a search, the central keywords in your the search engine's features. If you are looking for queries will be nouns. Though sometimes adverbs information that is hard to find, you can search more and adjectives can help refine your search, the key effectively by using the advanced search capabilities pivot point is a noun, or series of nouns. In our first of the search engines; 8. Wherever possible, use example, the noun is Drug, drugs. Actions (verbs) Boolean commands in your search query. Boolean and modifiers (adjectives, adverbs, predicate commands are specific words or symbols that allow subjects) are very diverse, easily substitutable, and you to include, combine, or restrict the keywords of generally not universally applied in any given your search. Some search engines will allow you to description. Search engines either return too many use Boolean commands only from the advanced "hits" for these words that are not very useful or search interface; 9. Some search engines do not 'throw them away". As a general rule, try to avoid support Boolean commands directly. They use the using action terms and mostly try to avoid using characters - and -instead of Boolean operators to modifiers in your queries. include and exclude terms. Most search engines will Use sufficient number of keywords in query. One allow you to use these implied Boolean commands; of the biggest mistakes you can make in preparing a 10. Each engine catalogs information in different query is not providing enough keywords. On average, ways. Knowing how each engine works helps to use most users submit 1.5 keywords per query. This the right search engine for the job. number is insufficient to accurately find the Refining your search. Search refining options information you are seeking. Thus, a central task in differ from one search engine to another. Some of the query formulation is for you to identify a sufficient possibilities include the ability to search on more number of appropriate keywords. In our first than one word, to give more weight to one search example, the possible keywords are new, drug, drugs, term than you give to another, and to exclude words therapy, treatment, cancer, and neoplasm. that might be likely to muddy the results. You might Truncate words to pick up singular and plural also be able to search on proper names, on phrases, versions. One of the mistakes in query formulation and on words that are found within a certain is not using word stemming, or truncation, proximity to other search terms. Many, but not all sufficiently. By using either only singular or plural search engines allow you to use so-called Boolean version of a word, we would eliminate about half of operators to refine your search. These are the logical the potential documents that we would like to use as terms AND, OR, NOT, and the so-called proximal our search basis. The better way to handle this locators, NEAR, BEFORE and AFTER. Boolean problem is through truncation. Truncation is Logic gives you an incredible amount of filtering applying a wildcard character after the first few control, and you can quickly obtain very targeted letters in a term (the "stem"). The asterisk (*) is the results. All the search engines have different almost universally accepted truncation wildcard. methods of refining queries. The best way to learn This wild card means any word or letter after this. them is to read the help files on the search engine Generally, you must also have a minimum of 3 sites. characters at the beginning of the word as your stem Search techniques and strategies.15,20-25,28-40 One basis. Once marked for truncation, then any matching recent study shows that two-thirds to three-quarters characters after that will be picked up in the search of all Web users cited the inability to find the query. In our examples, the keywords that can be information they seek as one of their primary truncated are as follows: Drug*, discover*, cancer*, frustrations.1 Part of this frustration is the result of treatment*, method* and weight los*. Remember, inability in applying proper search techniques. any words with characters after the stem will be Effective search techniques. Here is list of easy matched to your query term if the search engine to follow techniques and strategies that can definitely supports truncation. Thus, if we stem los*, our search boost your search engine's performance.7-11,12-28 will match on the words lose, losing, loss and lost.

Saudi Med J 2001; Vol. 22 (9) 753 Searching web-based medical information ... Mansoor

Use synonyms and variant word forms. Another highly that match first terms or phrases evaluated: way to increase your search effectiveness is to be as ("new drugs*") (discover* or find) ("Cancer specific as possible; that is including as many terms therapy"); (popular or common or favorite)(method* and synonyms as you can think of to fully describe or way* or technique*) (los* or reduc*) (weight or your topic. The best synonyms provide relatively fat or diet*). complete coverage for the subject at hand and are Link "concepts" with the AND operator. '"pitched" for the right informational objective. In our Combine keywords with Boolean AND. AND glues first example, the possible synonyms, alternate the query together. The resulting query is not overly spellings, and variant word forms of each keyword complicated nor nested, and proper left-to-right are as follows: drug*: therapy, treatment; cancer*: evaluation order is ensured: ("new drugs*") and neoplasm, malignant; discover*: find; popular*: (discover* or find) and ("cancer therapy") (popular or common, favorite; method*: way, technique; losing: common or favorite) and (method* or way* or lose, reduce, reduction; weight: fat, dieting, diet. A technique*) and (los* or reduc*) and (weight or fat or thesaurus, a dictionary, or personal knowledge can all diet*). Now issue these queries to a Full-Boolean be worthwhile places to find synonyms for the major search engine... subject(s) in your query. Things to remember when searching the Combine keywords into phrases where possible. Internet:24-26 1. Most search engines’ interpret lower A very effective way to increase the relevance or case letters as either upper or lower case. Thus, if you precision of "hits" is to search as a phrase. Phrases want both upper and lower case occurrences returned, are combinations of words that must be found in the type your keywords in all lower case letters. search documents in the EXACT order as shown. However, if you want to limit your results to initial You denote phrases within closed quotes (""). capital loners or all upper case letters, type your Phrases should be used where the constituent terms keywords that way. 2. Most search engines are are naturally married; like "lipo-protein" or insensitive to whether you use upper or lower case "lipoprotein*". It is a powerful search technique for for Boolean operators in your queries. 3. Many significantly narrowing your search results, and it search engines interpret singular keywords as should be used as often as possible. Some other singular or plural. If you want plural forms only, examples are "Ischemic heart disease", "Diabetes make your keywords plural. 4. Some of the search Mellitus", "Downs syndrome" etc. When using tools support what is called stemming. That means phrases, it is important to consider nuances of the they will find terms like "singing" even if you only phrase that wouldn't normally be of concern. For enter "sing". This also means you may not need to example, the spaces between words are as important use a wildcard symbol. 5. Avoid misspellings; as any other character. Some search tools provide search engines return websites with words that match specific options for phrases; some do not allow them your keywords. If you misspell a keyword, your at all, but almost all will allow you to enter a phrase results will contain websites where that word is also in quotes, ignoring the quotations if not supported. misspelled. 6. Not all search engines handle Combine synonyms with Boolean OR. Use punctuation equivalently. When in doubt, you should Boolean OR to string together synonyms. For consult the help file of the search engine you are example discover* or find; popular or common or using. 7. When searching hard-to-find information or favorite; method* or way* or technique*; los* or difficult topics, use search engines with full Boolean reduc* weight or fat or diet*. support. With full Boolean searching, you will have Combine 2 to 3 "concepts" in a query. complete control to find what you seek. 8. Some Triangulating on multiple query concepts narrows search engines present the Boolean operators as and targets results, generally by more than 100-to-l. options like "include all the words", (AND For example, the concepts in our examples could be operator)"include any of the words", (OR operator) as follows "Cancer therapy"; "new drugs*"; and "exclude" (NOT operator). 9. The search discover* or find; method* or way* or technique*; engines like Google, HotBot, Lycos, MSN Search, popular or common or favorite; weight or fat or and Northern Light default to an implied AND diet*; los* or reduc*. (which means if you enter 2 search terms it returns Distinguish "concepts" with parentheses. Nest documents in which they BOTH occur). On the other single query "concepts" with parentheses. Simple hand, most of the major search engines like Alta way to ensure the search engines evaluates your Vista, Excite, GoTo, Infoseek, Look Smart, Snap, query in the way you want, from left to right: WebCrawler, and Yahoo default to an unhelpful ("Cancer therapy") ("new drugs*") (discover* or implied OR (it returns documents in which EITHER find)(method* or way* or technique*) (popular or occur). 10. After following a link to a document common or favorite) (weight or fat or diet*) (los* or retrieved with a search engine, it is sometimes not reduc*). immediately apparent why the document has been Order "concepts" with subject first. Put main retrieved. This may be because the words for which subject first. Engines tend to rank documents more you searched appear near the bottom of the

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