Five Laws of Library Science

By S.R. Ranganathan, The Father of Library Science 1931
Books are for Use
Every Reader his/her Book
Every Book its Reader
Save the Time of the Reader
The Library is a growing Organism


                  In a Library there are two types of information sources are available. They are (A) Documentary sources and (B) Non- Documentary Sources.

(A)       Documentary Sources:-        All sources in the form of documents are documentary sources. A Selective list of documentary sources are given below:-

(1)        Treatises:-     It is a long and serious piece of writing on a particular subject. It is considered as a secondary source of information.

(2)        Monograph:-  It presents a detailed study on a single subject, class of subjects, or a person and is usually accompanied with a bibliography.Some publishers bring out monograph series as well.

(3)        Textbooks:-    A text book is a book that is used by students as a standard work for a particular branch of study.It uses in schools, colleges, universities to update the knowledge, prepare class notes, clarify doubts etc.

(4)        Reference Books:-     It used to find answers of queries.

(5)        Dictionaries:- A list of words of a language in alphabetical order and explains what they mean or gives a word for them in a foreign language. In monolingual dictionary , we get the meaning, definition, explanation etc of a word in the same language in which the dictionary is written. In bilingual dictionary we will get the meaning of a English word in one other language (Eg. English – Bengali). In Multilingual dictionaries we gets meaning of a word in different languages.

(6)        Thesauri:-       It gives a particular word which is best suited for  a particular context. So it is defined as a book that list words in group of synonyms and related concepts.

(7)        Encyclopedias:-          It contains informative articles of varying length ranging from a few lines to hundred pages or more There are two types of encyclopedias are there, ie General encyclopedias which categorized by volume, subject and user. The other type is Subject encyclopedias and which devoted  to a particular subject like physics or more that subject like science and technology. Some of these enclopedias are in one volume and are in two or more volumes.

(8)        Handbooks:-  It is small enough to held in the hand and are meant for practitioners and includes formulas, definitions, values of various constants, and so on which are required by practitioners. It is always devoted to a particular subject or subjects.

(9)        Manuals :       A manual is a book that gives instructions about how to use a machine and many other things.

(10)      Data Books and Tables:-      These are mostly used by statical and metrological departments for making datas in tabular forms for publications.

(11)      Catalogues:-   The catalogue holds bibliographic information about millions and millions of books emanated all over the world.

(12)      Bibliographies:-         A bibliography is a list of documents arranged in some logical order. An entry in a bibliography provides information about the author, title, edition, collaborators, imprint, collation etc of a book.

(13)      Directories:-   A directory lists names of person, institutions or organizations of a particular area.

(14)      Yearbooks:-   A yearbook, as the name suggests appears annually and updates information every year. They are various types and are categorized as, general and subject oriented, national, regional and international. The yearbooks portray the development in the particular subject during the preceding year.

(15)      Almanacs:-     It is an annual calendar containing important dates and statical information such as astronomical data. The various almanacs published in our country provide data in chronological order of all the days of the year.

(16)      Biographical Dictionaries:-   Biographical dictionaries are three types: Who is Who, Who was Who and a combination of both.

(17)      Maps:-            A map is a sheet of paper or similar material on which the earth’s surface, or part of it is shown indicating countries, oceans, seas, mountains, rivers, deserts, roads and so on.

(18)      Globes:-          A globe is a sphere the surface of which shows countries, oceans, seas, mountains, rivers, deserts, etc. Just like a map. It is mounted on a stand and can be rotated around its axis.

(19)      Atlases:-          An atlases is a book that usually contains maps and as index of places and other geographical entities indicating their locations in particular maps. Generally, by the term atlas, we mean only geographical atlases; however there are non-geographical atlases as well.

(20)      Gazetteers:-    A gazetteers is a dictionary of place names and other geographical entities with descriptive, statical, economical, geographical and historical information. It can be categorized as international, national, state and district.

(21)      Guidebooks:- Guidebooks are usually meant for tourists and provide them various information as required by them. For a place of tourist’s interest these books provide such informations when to go, how to go, where to stay, what to see, what to eat and so on.

(22)      Manuscripts:- Before the advent of printing men used to write in hand on papyrus, parchment, vellum, bhurjapatra, palm leaves, papers and other materials. Books produced in this way earned the name manuscripts. These manuscripts are unfolded a great deal of information about the ancient civillisations of the world.

(23)      Periodicals;-   A periodical is a publication with a distinctive title which appears At stated or regular intervals, without prior decisions as to when the last issue shall appear. Periodicals are categorized as primary, secondary, tertiary, research periodical, technical periodical, trade journal and house journal.

(24)      Patents :-        It means an official right given to a person to make , use or sell a product ,process, design, etc. invented by him/her for as fixed number of years. The patents are issued by the patent office of the country.

(25)      Standards:-    A standard is something set up and established by authority as a rule for the measure of quantity, weight, extent, value or quality. Here , we concerned with the documents that provide the detailed description of a standard published by a standard issuing institution of a country like our Bureau of Indian Standards.

(26)      Theses:-          A Thesis or dissertation is a document the contains details of a research conducted under the guidance of an expert. Apart from the hypotheses, objectives, scope , methodology, and results of the study, a thesis contains a detailed literature survey, which is useful for the compilation of a bibliography on the subject.

(27)      Conference documents:-       Thousands of conferences are held every year throughout the world and they generates different types of documents, announcements, call for papers, programs etc. It is called conference documents and it can be divided into two types, ie pre-conference documents and post-conference documents.

(28)      Souvenirs:-     A souvenir is something that is given to someone as a memento. When a souvenir takes the form of a publication, more often that not it becomes a good source of information. It act as a good reference source.           

(29)      Festschriften:-    A festschrift is a collection of writings published in honour of a learned person. Usually in a festschrift the biographical sketch of the person, discussion on his/her contributions, personal narratives about the person are included. In addition, a number of articles contributed by his/her professional colleagues, students, friends and others are also included.

(30)      Reports:-        Various types of reports are technical reports, administrative reports, trip reports etc.

(31)      Articles:-         An article is a piece of writing included with others in a periodical, newspaper, conference proceedings, festschrift and so on. Articles can also be categorized as popular , technical, research, review articles and soon.

(32)      Diaries:-          Writers, scientists, scholars and many others maintain diaries. These diaries provide most authentic biographical material and plenty of other information. Normally these diaries are handwritten and sometimes depending on their importance they are published also.

(33)      Letters:-          The practice of writing letters for communicating messages is very old. Even today this particle is continuing though with the spread of telephones and mobile phones it is showing signs of decline especially in the case of personal letters. With the advent of internet, the channel of communication has also undergone change Now, a huge number of letters has taken the form of e-mails.

(34)      Office files:-    All decisions, big or small, taken by the government, governing body of an academic body, industrial enterprise, a research institution, a society and so on are recorded in files.

(35)      Computer files:-         A computer file is a collection of records or programs stored under s single filename. A digitized form of a book, a periodical, a thesis etc. can be a computer file.

(36)      Database:-      A database is a collection of cross-referenced files so designed as to retrieve information from a number of angles. There are a number of vendors that posses plenty of online databases. Obtaining password from the vendor one can search all these databases from a single access point.

(37)      Video Recordings:-    A video recording harbours sound, colourful pictures and animation. Many documentary films recorded in videotapes are excellent sources of information. Here, one not only gets the narration, but also the relevant pictures along with animation. This gives much better impact on the minds of the people.

 (B)       Non-Documentary sources :-    There are two types of non documentary sources of information. They are Humans and Organisations.

(a)        Humans:-        Under humans there are numerous categories, some of the categories under the humans are,

(1)        Consultants:-  A consultant is a professional who provides advice usually on payment basis. There are various categories of consultant such as legal consultants, engineering consultants etc.

(2)        Experts:-         An expert is a person who posses sound knowledge on a subject, technique and so on. On many occasions we takes the help of these experts to solve some problems.

(3)        Resource Persons:-    A resource person is a person who have much intellectual power for giving outputs as per the situation.

(4)        Extension Workers:- The meaning of the extension worker is varies depending on the context. Examples of extension workers are Agriculture extension worker, Medical extension worker etc.          

(5)        Representatives of Firms:-    A representative is a person who is employed by a firm for sales promotion and allied activities. His/her activities among others, include sales promotion, market survey, study of user reaction, identifying competitors in the field, locate prospective buyers and so on.   

(6)        Technological Gatekeepers:-            A technological gatekeeper is a well-informed person in a particular field. Usually some scientists, technologists and professional in business etc have got a tendency to acquire information from various sources, to keep himself abreast of the development in the field and to disseminate the information to the person or group who may be interested in the information.

(7)     Common Men:-         In our day-to-day life , we gather plenty of information from common men.

(b)      Organisations :-   Organisations are also important sources of information. There are different categories of organizations and they provide different types of information. Information provided by an organization is generally considered to be authentic.