In PLWeb, you are strongly encouraged to use natural language queries. A natural language query is one that is expressed using normal conversational syntax; that is, you phrase your query as if making a spoken or written request to another person. There are no syntax rules or conventions for you to learn. Natural language queries generally find more relevant information in less time than traditional Boolean queries. Of course, there are times when you will need the narrow focus and precision that Boolean queries provides. For this reason, PLWeb fully supports Boolean searching.
Concept Search
Concept searching is done by entering a simple query describing your area of interest. In a concept search, PL generates a list of terms that are statistically related to the words in your query and performs a conventional search using the original words as well as the related terms. You will find that many of the records retrieved, while perhaps not having occurrences of your original query words, will nonetheless contain information that is relevant to your search interest.
Advisors
You can think of PLWeb's advisors as on-line over-the-shoulder assistants. In addition to giving you added insight into the nature of a database's contents, they provide you with powerful tools for boosting the effectiveness of your feedback searching activities.
You can:
Dictionary Advisor
When you use the Dictionary Advisor, it displays an alphabetical listing of all unique terms in the active database. Along with each index entry is a posting number, indicating the number of times the word occurs within the database. By highlighting terms from the list, and clicking on Add Terms to Query you can include dictionary terms with your original query.
Relate Advisor
You can use the relate advisor to identify potentially valuable query words that might not immediately come to mind. It generates, on-the-fly, a list of words in the current database that are statistically related to the words in your query. Words are deemed related if they exhibit a significant degree of co-occurrence within records. After selecting the Relate Advisor and clicking on the Get Results button. PLWeb returns the list of related terms. You can include related terms within your original query by highlighting terms from the list and clicking on Add Terms to Query.
Fuzzy Match Advisor
You can identify words in the database that have spellings similar to the first word you have entered in the Search Window. This can be helpful in finding word variants or misspellings in a database. After selecting the Fuzzy Match Advisor and clicking on the Get Results button, PLWeb returns the list of variant words. You can include any of these terms by highlighting terms from the list and clicking on Add Terms to Query.