Environmental Health - Toxic Substances Hydrology Program

Bibliographic Data Base Search Help

More Search Instructions

Searching a Word

  • The search for each word entered in the field will begin at the beginning of each word in the title or author fields. For example, if you enter "Morgan" in the author text input line you will find all references in the data base by "Morgan" as well as by "Morganwalp".
  • With the "Exact Match" check box selected the search engine will return only references by "Morgan" and not by "Morganwalp".
  • Stop words are filtered out and are not included in word searches, and special characters are either ignored or they will generate a pleasant error message.

Searching for More than One Word

  • Selecting one of the "AND" buttons (the default) under the title or author text input lines performs an "AND" search within the title or author field. For example, entering "organic chemicals" in the title text input line will limit your search to references with "organic" and "chemicals" in the title field.
  • Selecting one of the "OR" buttons under the title or author text input lines performs an "OR" search within the title or author field. For example, entering "organic chemicals" would expand you search to references with either "organic" or "chemicals" in the title field.

Searching for a Phrase

  • Selecting the phrase button at the end of the title or author text input lines limits your search to a particular phrase in the title or author fields. For example, entering "organic chemicals" in the tile field with the phrase button selected will limit your search to references with "organic chemicals" in the title.
  • Phrase searches start at the beginning of words in the title or author data base fields. For example, entering "-Resources Invest" to find all Water-Resources Investigations Reports in the data base will end up in an empty search because "-Resources Invest" does not start at the beginning of a word.
  • If special characters are entered they will generate a pleasant error message.

Stop Words

  • Stop words are words so common that they occur in almost every reference and they are not used in searching for words in the title or author fields of the data base. For example, "toxic" is a stop word. Entering "toxic" as a search term will result in hundreds of references on many different aspects of the Toxic Substances Hydrology Program. This would not be a very useful search: therefore, the word "toxic" and many like it are filtered out of searches.

Special Characters

  • Characters in your search terms that are not alphabetical, numeric, a period, a comma, or a dash are not allowed. If you enter a character other than these a pleasant error message will be generated and you will be asked to try again.
  • If the "AND" or the "OR" search button is selected, periods, commas, and dashes are filtered out. For example, if you were looking for Water-Resources Investigations Report 91-4034, and you put "91-4034" in the title field and the "AND" search button was selected, the "-" would be ignored, and you would find documents that had "91" and "4034". However, the "4034" would not be found because the "4034" does not start at the beginning of a word. The best way to find this report number would be to enter it in the title text input line with the phrase search button selected.
  • Be wary of using the author's initials.

Boolean Operators

  • Boolean operators, such as "AND", "OR" and "NOT" are not implemented in this version of the Toxics Bibliographic Data Base Search Engine.
  • All multiple field searches in the data base are AND searches. For instance, searching for references from the Bemidji Minnesota Research Site containing the phrase "organic chemicals" (phrase button selected) in the title would return only those documents from the Bemidji Site that contain the phrase "organic chemicals".
  • If you entered "organic AND chemicals" or "organic OR chemicals" in the title text input line the stop words "AND" and "OR" would be filtered out and the search engine would return references with "organic" and "chemicals" in the title field (this is true only when the default "AND" radio button is selected.
  • AND and OR searches are possible for subsearches within the title and author fields by selecting the "AND" or "OR" radio search buttons.

Natural Language

  • The data base can be queried using natural language questions, but the server does not understand the questions; rather, it takes the words in the questions and finds references that have those words in them.
  • "Tell me about subsurface environments" is an example of a natural language question. In this example, the server would search for documents containing the words "subsurface" and "environments"; the other words, "tell", "me", and "about", are called "stop words" - words so common that they occur in almost every reference. Stop words are filtered out and are not part of a search query.

Phrases (Literal Strings)

  • One can find an exact phrase by selecting the phrase radio button. For example, the query "transport of organic chemicals" returns only documents that contain this exact phrase.

Wildcards

  • The search engine does not recognize wildcards such as "*" and "?".
  • Entering one of these characters will generate a pleasant error message.

Exact Matches

  • The "Exact Match" checkbox is used to search for exact matches with the search terms you enter. For example, if you enter "Morgan" in the author text input line the search engine will return only references by "Morgan" and not by "Morganwalp".
  • Exact Matches apply only to word searches and not to phrase searches.

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