How to search the internet 5: advanced operators

13/05/2010

This is part 5 of my guide to searching the internet. Here are links to:

Part 1: History of internet search;
Part 2: How a modern web search site works;
Part 3: How to actually use a modern search engine
Part 4: How to understand the results you get from using a modern web search

I covered basic use of operators in part 3. But the proper use of operators is very important if you want to get the most from a search engine, especially if the search is at all complicated. So I’m going to go into more detail on the subject here. I got much of the info from other sites, especially www.GoogleGuide.com. But I (rather modestly) think that i present the info in a much more readable and usable form.

Okay, here we go. Operators are special uses of certain words or combination of words that mean more to the search engine than the plain use of words as simple search terms. Here’s a quick example, which you may find familiar if you’ve ever learned how to use Google to find mp3 files: Let’s imagine we want to find mp3 files of tracks by the excellent early British punk band The Clash. What we actually find are listings of the contents of directories that contain the mp3 music files. So, we could use Google search terms like this:

intitle:index.of mp3 “the clash” -.html -.htm

Let’s examine that bit by bit. It starts with intitle:index.of. The intitle part tells Google to look in the title of a page for a particular word or phrase. In this instance, the phrase to look for is index.of (which would, incidentally, look for titles that include the string “index.of” and “index of” (ie with a space rather than a period). That’s how Google and most (all?) other modern search engines work. The reason for looking for a page whose title includes the phrase “index of” is that a web page listing the contents of a directory will very likely have a title containing those words. It’s also looking for the word mp3 and the phrase “the clash”. You’ll notice we used quotation marks around “the clash”. This is my personal preference: the band was called The Clash, so I want results that contain that band name. Some people disagree, thinking that cuts out a lot of relevant results. And it’s true that some webmasters may have used the word “clash” in the page title. But I think using the word “clash” would pull up lots of irrelevant results like “Clash of the Titans” and “clash of two cultures”. So I stick with the phrase “the clash”. Whether you go with my suggestion or not is up to you.

The last 2 operators in this search are -html and -htm. You see, we’re looking for a page that lists the contents of a directory. This is not a page that is destined to be viewed by site users – it has more of a “housekeeping” function. And as it isn’t meant to be viewed by general users, it is very unlikely to contain mark-up. We’re not looking for marked-up pages; so we don’t want pages whose titles are suffixed .htm or .html. That operator means the same as the NOT operator.

So, that was just a quick example of how operators are used to help construct a search term. Now let’s have a look at what operators are available to a search engine user:

city1 city2: this will look for info on flights from city 1 to city 2. We don’t use the actual names of the city though, we use the 3-letter airport codes. For instance, the search sfo bos will pull up times and info on flights from San Fransisco; whereas the search san fransisco boston pulls up some flight info but also a lot of unrelated results. You can find the 3-letter codes for airports worldwide here.

Here’s some more stuff about advanced Google search operators (with thanks to GoogleGuide.com):

allinanchor:
If you begin your query with allinanchor: Google restricts results to pages containing all query terms you specify in the anchor text on links to the page. Example: the query allinanchor: best museums birmingham will return only pages in which the anchor text on links to the pages contain the words best, museums and birmingham.

Anchor text is the text on a page that is linked to another web page or a different place on the current page. When you click on anchor text, you will be taken to the page or place on the page to which it is linked. When using allinanchor: in your query, do not include any other search operators. The functionality of allinanchor: is also available through the Advanced Web Search page, under Occurrences.

allintext:
If you start your query with allintext:
Google restricts results to those containing all the query terms you specify in the text of the page. For example, allintext: travel packing list will return only pages in which the words “travel”, “packing” and “list” appear in the test of the page. This functionality can also be obtained through the Advanced Web Search Page, under Occurrences.


How to search the internet 3: how to actually *use* a search engine

08/04/2010

Okay, this is the 3rd part of my series on how to search the internet. Part 1 briefly covered the history of internet search; part 2 looked (again, very briefly) at how modern search engines like Google work; and now we come to the nitty-gritty: how we actually use a search engine to find the stuff we want. Part 4 will look at how to understand the results brought by the search engine.

The first method we’ll look at is the method most people think of using – the keyword search. This involves thinking about what it is you want to find, then choosing words that concisely describe the object of your search.

Imagine we want to find out about giraffes. We could type the word giraffe into Google (or whatever search site we’re using – I’m going to use Google as an example, but this should be relevant for other search engines too). So, we tell Google to search for giraffe: and Google turns up 8,550,000 possible results.

Now, that is an awful lot of web pages to trawl through to find whatever it is we want to know about giraffes. And a lot of them won’t be relevant at all. If you look at the result page for the search on giraffe you’ll see that the very first result is for Giraffe Restaurants – probably not what we want.

So we need to think about what we’re looking for. Let’s imagine we want to know about what giraffes eat. We could search for giraffe food – but then we run into that problem of sites for restaurants and other human food companies with the word “giraffe” in their names.

Giraffe feeding habits would be better – it garners us some 274,000 results – but also excludes pages where the word “habits” isn’t used, for instance where the phrase “feeding behaviour” is used instead. So what about using giraffe feeding? Google gives us 618,000 results for that, but maybe will include useful pages that we might otherwise miss.

And what about giraffe feed? That gives us a massive 1,300,000 results; but this more comprehensive search will give us “feeds” and “feeding”, and sentences like “how a mother giraffe feeds its young” and “what kind of feed for a giraffe in captivity”; and Google will also pick up on the word “fed”, which might be important. It all depends on what exactly we want to find.

But anyway, both 274,000 and 1,300,000 are a lot of results to trawl through. So some further refining of search terms may be order. What precisely do we want to know? Are we after info relating to giraffe feeding habits in captivity rather than in the wild? If so, we can search for giraffe feed captivity which gets us just 21,500 results! Yes, 21,500 links is still a lot to check, but it’s an awful lot better than the 2,160,000 pages we started with!

Sometimes users might want to use search terms in the form of a question – for example what should you feed a giraffe in captivity. This is generally considered to be a bad idea, because a question might contain words that wouldn’t actually appear in a web page you want to find. Google has a feature called stop words: this tells Google to not search specifically for certain commonly used words (like you, what, in… I’m sure you get the idea. But sometimes we might want Google to include stop words in its search. For instance, we might be searching for references to the movie “How The West Was Won”. To do this, we use quotation marks in the search terms; ie we tell Google to look for “how the west was won”. Then Google will look for pages that include the complete phrase.

Another poor use of search terms would be to tell the search engine to look for articles on feeding giraffes or documents about the care of giraffes in captivity. While those would be reasonable instructions to give to a human, they are not appropriate terms for a search engine. Remember, a search engine is a computer program, and computer programs are stupid. They’re good at doing exactly what we tell them to do; but the pages we’re looking for probably wouldn’t contain the words “articles on…” or “documents about…” so using those phrases will exclude many pages that we would actually want.

Another way to craft useful search terms is through the use of operators. Operators are query words that have a special meaning to search engines. You can find some excellent examples of operators and how to use them at Googleguide.com; but I’ve provided a few examples here so you can quickly get an idea of what this operator thing is all about:

If we wanted to find info about recycling steel or recycling iron, we would use the operator OR, like this: recycle steel OR iron. If we used the search terms recycle steel iron without that OR, the search engine would look for pages that included the words “steel” and “iron”; it wouldn’t bother showing us pages that included just one of the words without the other and we might miss very useful pages. Using the capitalization with OR helps the search engine to understand that it’s meant as an operator.

If we wanted to find pages that contained information about Steve Davies but which explicitly did not mention snooker, we could use the operator NOT or the symbol, like this: “steve davies” NOT snooker or “steve davies” -snooker. (Notice too that we’ve put the name Steve Davies in quotes, so the search engine knows we are specifically looking for the name Steve Davies and not looking for pages that mention, for example, Steve Jones and David Davies.)

We can use the + symbol to help focus on a particular search term and possibly weed out others. For example, if we are looking for references to King Louis I of France in particular and not any other French kings, we can search for Louis +I France.

We can use the define: operator to learn the definition of a particular word. For example, to find out what the word “cantata” means, we can search for define:cantata. This will give us a selection of definitions of “cantata” from various online dictionaries.

If you aren’t too confident about the correct usage of operators, you can use the advanced search option with some/many/most search engines. For example, with Google you can click on Advanced search and you will be presented with a form that has a number of search term entry fields. This gives you a simple way of setting a number of parameters to your search. But if you’re confident with using operators, you can construct pretty complex search parameters using just the standard entry field.

When you are crafting terms for a particular search, it comes down to common sense at the end of the day. Just plugging in in one or two search terms might be enough for a simple search; but if things aren’t really simple, you need to give some thought to what exactly it is that you’re looking for. If you want to know about how to use the knight in chess, a search for knight +chess will be much more useful than just typing in the word knight or the question how does the knight move in chess. A little forethought can save you a lot of time, by giving you a much shorter list of results to trawl through.

Well, I think that’ll do for this part of my guide to using search engines. I realize I haven’t provided a comprehensive list of all the operators available, or all the search strategies you can use – but it would have been pretty futile for me to even attempt that. There are a number of search engines, and they’re not all the same. I advise you have a look at www.googleguide.com to pick up some tips on using Google (the most popular search engine on the web), and The Spider’s Apprentice for some more general advice. But believe me: while both of those sites are very interesting, they’re certainly not essential. This blog post, with a dollop of common sense on the side, should get you plenty of useful results to any search queries you might make.

This isn’t the end though – oh no, not by a long chalk. I’ve told you how to get results – now you need to know how to use them. Which is what I’ll cover in Part 4 of my guide to internet search.

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How to search the internet 1: the history of search

29/03/2010

This is the first part of my guide to web search; the second part is here; part 3 is here. Part 4 is here.

The first search engine is widely considered to be Archie: a tool for indexing FTP archives which enabled users to locate resources. Its first implementation was written in 1990 by Alan Emtage, Bill Heelan, and J. Peter Deutsch, then students at McGill University in Montreal. It started off as basic lists of files that were accessed using the Unix command grep. Later, more efficient front- and back-ends were developed, and the system spread from a local tool, to a network-wide resource, to a popular service available from multiple sites around the Internet. The archie servers could be accessed in various ways: by use of a local client; by telnet; by email; and later through the World Wide Web. As the web became more widespread, its simpler interface made archie obselete, and now there are very few archie servers to be found on the internet. Wikipedia mentions an archie gateway still up in Poland; maybe that’s the last one?

Then there was Gopher – a protocol for distributing, searching, and retrieving documents over the Internet, dating from about 1991 and used throughout the 1990s. It was a predecessor of, then for a while an alternative to the World Wide Web. Wikipedia describes it as:

a TCP/IP Application layer protocol designed for distributing, searching, and retrieving documents over the Internet, and was a predecessor, and later, an alternative to the World Wide Web. The protocol offers some features not natively supported by the Web and imposes a much stronger hierarchy on information stored on it. Its text menu interface is well-suited to computing environments that rely heavily on remote computer terminals, common in universities at the time of its creation in 1991 until 1993.

Gopher was called Gopher for 3 reasons:

1. Users instruct it to “go for” information;
2. It does so through a web of menu items allegedly analogous to gopher holes;
3. It was developed at the University of Minnesota, whose sports teams are the “Golden Gophers”.

Its user interface (text, based on menus) suited the computer environment of the 1990s – mostly command-line interface on remote terminals. But by the late 90s, as graphical interfaces to the internet became more common (thanks to web browsers like Mosaic, whose integration of text and images was much more user-friendly than Gopher’s text-menu approach) Gopher was in decline. Although it still exists on the internet, it is used mostly for nostalgic reasons.

As the web became ubiquitous, and huge numbers of websites were created, organisations began to collate lists of these sites into directories. Yahoo, Lycos and the Open Directory are examples. These directories listed sites in categories by content: for instance, if you were looking for a particular site about photography, you would look through Yahoo’s list of photographic sites.

But as the web grew ever bigger, it seemed to many people that directories became too unwieldy: if you’re looking for a site about a particular photographer and you’re confronted with a list of 50,000 sites, you’ll probably give up in despair. This is where the modern search engine comes in – the likes of Google and Bing. We’ll get into all that in the next instalment of this little guide to internet search.

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