So far in our lessons and examples, we have used the asterisk * as the truncation symbol. Most of the time, the asterisk will work. However, depending on how the database or search engine has been designed, sometimes the truncation symbol may be a question mark ? or an exclamation mark ! instead.
If you are not sure, you can always ask a librarian or your teacher for help. Usually, the * will work. Many search engines and database have a search tips or advanced search tips or help link that will tell you which truncation symbols will work in that particular resource. Here's an example.
Actually, there are two "last note"s on truncation.... here is the second and final "last note":
So far, we have looked only at truncation, which means that you supply the root of the word and the computer finds all the endings. There is, however, another way of using these symbols ( * ? !) that you should be aware of, even if you don't use it right away.
The truncation symbols can also be used as wildcards. A wildcard replaces one character in a word. Here are some examples of how a wildcard works:
ne?t would find next, nest, and neat
wom!n would find women or woman
*symmetry would find asymmetry and symmetry
??ychology would find psychology
(good when you forget how to spell a word!)
You see how it works? Wildcards are good for many things. As with truncation, you can use them to find several words from one search term. They can also help when you aren't sure of a word's spelling. You can see from the examples above that they can be very useful, depending on what you are looking for. Also, notice that you can control the number of characters to be found by using more than one wildcard, as with the ??ychology example above.
Like truncation symbols, wildcards are different for each database or search engine. You must look at the search tips or help link to determine which wildcard will work.
One last note concerning 
