Why bother to use anything except Google? Read on to find out why using multiple search engines can be a good idea.
What's Wrong With Google?
If you're searching for something on the Internet, why would you use anything other than Google? Why bother using different search engines when Google generally has the best results?
There are several reasons, the primary one being that Google doesn't always offer the best results. Let's take a look at some cases when you would want to use alternative search engines.
Educational and Academic Searches
While the main search engines (Google, Yahoo!, and Bing) will find (an approximation of) the best match from everything on the Internet, sometimes you need a way to get only appropriate results. For example, rather than letting your children use Google to look up facts for their homework, you can point them towards child-friendly search engines; there are a number of such engines which make it easier for younger users to find what they're looking for, and may restrict their search results to sites that are age-appropriate.
At the other end of the spectrum, we have university students, professors, and professionals who need to find only technical and academic literature; Google Scholar allows you to see only appropriate results and is extremely useful for researchers.
Sometimes (actually, much of the time) you don't really want to see a list of search results; you just want an answer. Google does this, to some extent; you can type a simple math problem into the search and it will display the answer, or type a stock symbol in and it will give you the current price. Research is ongoing into how to have computers automatically sift through the data they have available to parse your question and calculate the answer; one example is the Wolfram|Alpha computational knowledge engine.
The advantage of this type of system is that the data is checked by human experts, so you get one right answer instead of a large number of different answers. The disadvantage is that the data is checked by human experts, so the amount of information available is limited to how quickly those experts can add it in to the system, rather than the exponentially faster rate at which knowledge is created.
Different Result Types
Sometimes you're only interested in one particular type of result, such as images, blogs, videos, and so on. By using a search engine that specializes in these results (for example, Google Image Search), you can get only the type of result you're interested in, and generally have access to additional search qualifiers (such as image size) to help narrow down your search.
Another reason you might use different search engines is to preserve your privacy. Given enough of your searches, even without much in the way of identifying information, it could be possible to identify you and locate information you'd rather not have known. An insurer, for example, might be interested in knowing that someone applying for health insurance has been looking for information about cancer symptoms. Even if you have privacy features turned on in your browser, the search engine can still record what searches are coming from your IP address.
There are a number of anonymous search engines that will allow you to get results, either from them or from the major search engines, without any information about your search histories being recorded or stored; as a result, you can browse with your privacy in place.