dtSearch Web

Introduction

To search using dtSearch Web, enter a search request in the space provided and click the Search button.   dtSearch Web will return a list of the documents that match your request.  To view a document in the list, click on the link.  After you have opened a document in dtSearch Web, you can use the Next Doc and Prev Doc buttons on the button bar to navigate from document to document.

You can move directly to the first, next or previous occurrence of the search term by using the First Hit Word(s), Next Hit Word(s) or Prev Hit Word(s) buttons on the button bar.

Search Requests Overview

dtSearch supports two types of search requests. A natural language search is any sequence of text, like a sentence or a question. After a natural language search, dtSearch sorts retrieved documents by their relevance to your search request.

A boolean search request consists of a group of words or phrases linked by operators such as and and or that indicate the relationship between them. Examples:

If you use more than one operator, you should use parentheses to indicate precisely what you want to search for. For example, bus and train or public transport could mean (bus and train) or public transport, or it could mean bus and (train or public transport).

Noise words, such as if and the, are ignored in searches.

Search terms may include the following special characters:

Words and Phrases

You do not need to use any special punctuation or commands to search for a phrase. Simply enter the phrase the way it ordinarily appears. You can use a phrase anywhere in a search request. Example:

transport policy

If a phrase contains a noise word, dtSearch will skip over the noise word when searching for it. For example, a search for statue of liberty would retrieve any document containing the word statue, any intervening word, and the word liberty.

Wildcards (* and ?)

A search word can contain the wildcard characters * and ?. A ? in a word matches any single character, and a * matches any number of characters. The wildcard characters can be in any position in a word. For example:

appl* would match apple, application, etc.
*cipl* would match principle, participle, etc.
appl? would match apply and apple but not apples.
ap*ed would match applied, approved, etc.

Use of the * wildcard character near the beginning of a word will slow searches somewhat.

Natural Language Searching

A natural language search request is any combination of words, phrases, or sentences. After a natural language search, dtSearch sorts retrieved documents either by date (the default) or by their relevance to your search request.

When sorting by date the retrieved documents are listed in reverse chronological order. When sorting by relevance the weighting of retrieved documents takes into account: the number of documents in which each word in your search request appears (the more documents a word appears in, the less useful it is in distinguishing relevant from irrelevant documents); the number of times each word in the request appears in the documents; and the density of hits in each document. Noise words and search operators like NOT and OR are ignored.

Stemming

Stemming extends a search to cover grammatical variations on a word. For example, a search for fish would also find fishing. A search for applied would also find applying, applies, and apply. There are two ways to add stemming to your searches:

1. Set the option in the Stemming box in the search form to enable stemming for all of the words in your search request. Stemming does not slow searches noticeably and is almost always helpful in making sure you find what you want.
2. If you want to add stemming selectively, add a ~ at the end of words that you want stemmed in a search. Example: apply~

AND Operator

Use the AND operator in a search request to connect two expressions, both of which must be found in any document retrieved. For example:

dublin bus and transport policy would retrieve any document that contained both phrases.

(car or vehicle) and (safety w/5 strategy) would retrieve any document that (1) contained either car OR vehicle, AND (2) contained safety within 5 words of strategy.

OR Operator

Use the OR operator in a search request to connect two expressions, at least one of which must be found in any document retrieved. For example, dublin bus or bus atha cliath would retrieve any document that contained dublin bus, bus atha cliath, or both.

AND NOT Operator

Use AND NOT in front of a search expression to exclude documents from a search. Example:

public transport and not bus  

W/N Operator

Use the W/N operator in a search request to specify that one word or phrase must occur within N words of the other. For example, bus w/5 train would retrieve any document that contained bus within 5 words of train. The following are examples of search requests using W/N:

(bus or train) w/5 policy
(bus w/5 train) w/10 policy
(bus and train) w/10 policy

Some types of complex expressions using the W/N operator will produce ambiguous results. In general, at least one of the two expressions connected by W/N must be a single word or phrase or a group of words and phrases connected by OR. Example:

(rail or train) w/10 (policy or strategy)
light rail w/10 (policy or strategy)

NOT W/N Operator

The NOT W/ ("not within") operator allows you to search for a word or phrase not in association with another word or phrase. Example:

Unlike the W/ operator, NOT W/ is not symmetrical. That is, bus not w/20 train is not the same as train not w/20 bus. In the bus not w/20 train request, dtSearch searches for bus and excludes cases where bus is too close to train. In the train not w/20 bus request, dtSearch searches for train and excludes cases where train is too close to bus.

Numeric Range Searching

A numeric range search is a search for any numbers that fall within a range. To add a numeric range component to a search request, enter the upper and lower bounds of the search separated by ~~ like this:

train w/10 18~~25
public transport w/20 1995~~2000

The first request would find any document containing train within 10 words of a number between 18 and 25.

A numeric range search includes the upper and lower bounds (so 18 and 25 would be retrieved in the first example).

Numeric range searches only work with positive integers.