Seminar: Boolean Search Model
The word “Boolean” derived from George Boole a British mathematician.
George Boole in the period of 1815-1864 devised a system of symbolic logic, in which he used three operators, viz. +, *, - to combine statements in symbolic logic, from John Venn later expressed. Boolean logic relationships through what are known as “Venn diagrams”. The three operators of Boolean logic are the logical sum (+), logical product (*), and logical difference. Information retrieval systems allow expressing their queries by using these operators.
The technical definition of Boolean is of or relating to a logical combinatorial system treating variables, such as propositions and computer logic elements. Through the operators AND, OR, NOT
Boolean Query Formulation:
Boolean query logic is one of the popular methods of query logic used for searching required information.
Historically the first and still the most common method used for expressing micro logic in query statements is Boolean Algebra. This is involves specifying the operations to be performed on sets that have been defined by relationship statements or precious set operation. A text system should provides for query formulation by using Boolean AND, OR, NOT.
1. AND: Logical product or AND logic allows, the searches to specify the coincidence of two or more concepts.
For example:- a) RIVERS AND SALINITY
It would contain records with both the desired Rivers AND desired Salinity. This is called “Logical product”
Intersection portion of the both River AND Salinity portion called Retrieved set. This diagram is called Venndiagram.
b) Intersection portion of the both Diary products AND Export AND Europe
2. OR: - Logical sum OR logic allows the searcher to specify alternatives among search terms (or concepts)
For example:- This is written as fruit a Vetables and it is called the logical sum Fruit as well as Vegetables
b) Retrieval system OR Computers
Search in the web, the web page will be open and displayed retrieval system as well as about computer but somany sites was opened about computer. Only few sites were opened in Retrieval system.
2. NOT:- Logical difference NOT logic provides to exclude items from a set.
For example: - a) FRUIT NOT APPLES
I want Fruit but NOT Apples.
b) Movies AND News NOT Advertisements
I want Movies AND News NOT Advertisements
Limitations of Boolean logic:
1. The Boolean retrieval mechanism tends to have an all-or-nothing quality. That is logical expression true otherwise false.
2. The logic of sets focus the value-judgement regarding a document into a binary scale either relevant or notrelavent.
3. Boolean logic makes it difficult to very depth of search in order to very the number of records or quantity of information required unless terms.
4. Complex searches are difficulty. Consisting of many different and connected parts.
5. Retrieve document can’t be ranked.
As we have seen the concept of Boolean search models. It is important in developing to library and information science. Boolean search was similar document will be retrieved. Most of the library users a quicker search service from the entire above search technique can retrieve the Information easily and quickly.
1. Meadow, Charles, T. Text Information retrieval systems. Academic press inc, 1992.