Primary Sources
Primary Sources are first hand and original materials. This type of information is from the time period involved and has not been filtered through any interpretation. They are usually the first formal appearance of results in physical, print or electronic format on which other researches are based. They present original thinking, report a discovery, or share new information. Primary sources are unorganized or uninterpreted sources, which are rather difficult to use by themselves.
Examples:
i) Artifacts, an object made by a human being, typically one of cultural or historical interest (e.g. coins, plant specimens, fossils, furniture, tools, clothing, etc.);
ii) Audio recordings (e.g. radio programs);
iii) Diaries/journals;
iv) Internet/digital communications on email, list-server, online social networks, SMS, online chat transcripts;
v) Interviews (e.g., telephone, online interviews (via e-mail or via chat technology);
vi) Articles published in peer-reviewed journals or publications;
vii) Letters;
viii) Articles in newspapers written at the time;
ix) Serial publications (Periodicals): These include journals, transactions, proceedings or similar works, which appear regularly and continuously in numbered sequence, e.g., Nature, Historical Journal
x) Oral history (i.e., records of interview, legal proceedings)
xi) Original documents (i.e. birth certificate, will, marriage certificate, trial transcript);
xii) Patents;
xiii) Standards;
xiv) Research monographs; (separately published reports on original research)
xv) Photographs;
xvi) Proceedings of meetings, conferences and seminars, symposia;
xvii) Records of organisations, government agencies (e.g., annual report, treaty, constitution, government document);
xviii) Speeches (i.e., transcripts or recordings);
xix) Survey Research Statistics (e.g., market surveys, public opinion polls);
xx) Video recordings (e.g., live events, television programs);
xxi) Works of art, architecture, literature, and music (e.g., paintings, sculptures, inscriptions on tombstones, musical scores, buildings, novels, poems);
xxii) Ephemera (e.g., brochures, pamphlets, postcards, program sheets, advertisements);
xxiii) Website (i.e., sites, blogs, social networks).
Secondary Sources
Secondary sources are interpretations and evaluations of primary sources. They are not evidences, but rather commentary on and discussion of evidences. These types of information are either compiled from or refer to primary sources of information. Generally, they are accounts written after the fact with the benefit of hindsight. These are the original sources having been modified, selected or reorganized (or repackaged) so as to serve a definite purpose or group of users. Secondary sources are easily and widely available as compared to primary sources. These also serve as bibliographical keys to primary sources. The user may consult the secondary sources first which will lead him/her to specific primary sources.
Examples:
a) Bibliographies;
b) Indexing and abstracting periodicals;
c) Reviews; Treatise;
d) Biographical works;
e) Commentaries, criticisms;
f) Dictionaries, encyclopaedias, handbooks, tables, formularies;
g) Magazine and articles published in newspapers (this distinction varies by discipline);
h) Monographs (books excluding fiction and autobiography);
i) Textbooks.
Tertiary Sources
Tertiary sources consist of information which is extracted from primary and secondary sources. These will aid the user of information in the use of primary and secondary sources of information. Most of the tertiary sources do not contain subject knowledge. The prime function of a tertiary source is to aid the searcher in the use of primary and secondary sources of information. Out of various kinds of sources, tertiary sources are the last to appear.
Examples:
a) Bibliography of Bibliographies; (list of bibliographies which direct readers to useful bibliographies through subject or name of an individual, place, institution, etc. e.g., bibliographic index, cumulative bibliography of bibliographies)
b) Chronologies;
c) Directories; (a list of names and addresses of persons, organisations, manufactures or periodicals, e.g., World of Learning, Ulrich's International Periodicals Directory)
d) Guidebooks (Guides to literature, guides to libraries and guides to organisations);
e) Lists of research in progress;
f) Indexes, abstracts, bibliographies used to locate primary and secondary sources;
g) Manuals;
h) Fact books;
I) Databases
