List of academic disciplines

An academic discipline, or field of study, is a branch of knowledge which is taught and researched at the college or university level. Disciplines are defined (in part), and recognized by the academic journals in which research is published, and the learned societies and academic departments or faculties to which their practitioners belong.

Fields of study usually have several sub-disciplines or branches, and the distinguishing lines between these are often both arbitrary and ambiguous. ^[1]

Contents 1 Overview 2 Humanities 2.1 History 2.2 Languages and linguistics 2.3 Literature 2.4 Performing arts 2.5 Philosophy 2.6 Religion 2.7 Visual arts 3 Social sciences 3.1 Anthropology 3.2 Archaeology 3.3 Area studies 3.4 Cultural and ethnic studies 3.5 Economics 3.6 Gender and sexuality studies 3.7 Geography 3.8 Political science 3.9 Psychology 3.10 Sociology 4 Natural sciences 4.1 Space sciences 4.2 Earth sciences 4.3 Life sciences 4.4 Chemistry 4.5 Physics 5 Formal sciences 5.1 Computer sciences 5.2 Logic 5.3 Mathematics 5.4 Statistics 5.5 Systems science 6 Professions and Applied sciences 6.1 Agriculture 6.2 Architecture and design 6.3 Business 6.4 Divinity 6.5 Education 6.6 Engineering 6.7 Environmental studies and Forestry 6.8 Family and consumer science 6.9 Health sciences 6.10 Human physical performance and recreation* 6.11 Journalism, media studies and communication 6.12 Law 6.13 Library and museum studies 6.14 Military sciences 6.15 Public administration 6.16 Social work 6.17 Transportation 7 See also 8 Notes 9 References 10 External links

Overview

The University of Paris in 1231 consisted of four faculties: Theology, Medicine, Canon Law and Arts.^[2] Most academic disciplines have their roots in the mid- to late-19th century secularization of universities, when the traditional curricula were supplemented with non-classical languages and literatures, social sciences such as political science, economics and public administration, and natural science and technology disciplines such as physics, chemistry, biology, and engineering.

In the early 20th century, new disciplines such as education, sociology, and psychology were added. In the 1970s and 1980s, there was an explosion of new disciplines focusing on specific themes, such as media studies, women's studies, and black studies. Many disciplines designed as preparation for careers and professions, such as nursing, hospitality management, and corrections, also emerged in the universities. Finally, interdisciplinary scientific fields such as biochemistry and geophysics gained prominence as their contribution to knowledge became widely recognized.

There is no consensus on how some academic disciplines should be classified, e.g., whether anthropology and linguistics are social sciences disciplines or humanities disciplines. More generally, the proper criteria for organizing knowledge into disciplines are also open to debate.

An asterisk (*) denotes a field whose academic status has been debated among this article's editors.

Humanities

History

See also Branches of history

African history American history Ancient history Argentine history Chinese history Cultural history Diplomatic history Economic history Ethnohistory

European history History of science and technology Iranian History Indian History Indonesian History Intellectual history Military history Modern history World history

Languages and linguistics

See also List of languages, Branches of linguistics, Anthropological linguistics

Applied Linguistics Computational linguistics / Natural language processing Discourse analysis Etymology Historical linguistics History of linguistics Interlinguistics Morphology Philology Phonetics Phonology Pragmatics

Semantics Semiotics Sociolinguistics Syntax Composition studies Rhetoric Languages Classics Standard English Business English World Englishes Modern language

Literature

English literature American literature African American literature Jewish American literature Southern literature Australian literature British literature English literature Scottish literature Welsh literature Canadian literature Indian literature Irish literature New Zealand literature Medieval literature Post-colonial literature Post-modern literature West Indian literature World literatures Arabic literature Argentine literature Bulgarian literature Classics Comparative literature Chinese literature French literature Gaelic literature German literature and Austrian literature

Bengali literature Hindi literature Hebrew literature Japanese literature Italian literature Latin American literature Nigerian literature Persian literature Polish literature Portuguese and Brazilian literature Russian literature Serbian literature Spanish literature Yiddish literature Tamil literature Welsh Literature Literary theory Critical theory Literary criticism Poetics Rhetoric Creative writing Creative nonfiction Fiction writing Non-fiction writing Literary journalism Poetry composition Screenwriting Playwrighting

Performing arts

Arts administration Music Accompanying Chamber music Church music Musical composition Conducting Choral conducting Orchestral conducting Wind ensemble conducting Early music Jazz studies Music education Music history Music theory Musicology Ethnomusicology Performance and literature Organ and historical keyboards Piano Strings, harp, and guitar Voice (Singing) Woodwinds, brass, and percussion

Recording Orchestral studies Dance Choreography Dance notation Ethnochoreology History of dance Theatre History Acting Directing Design Dramaturgy Playwrighting Scenography Musical theatre Film Animation Film Film criticism Film theory

Philosophy

See also Branches of philosophy

Meta-philosophy Metaphysics Ontology Teleology Philosophy of mind Philosophy of artificial intelligence Philosophy of perception Philosophy of space and time Philosophy of Action Epistemology Ethics Normative ethics Meta-ethics Theory of value Moral psychology Applied Ethics Animal rights Bioethics Environmental ethics Aesthetics/Philosophy of Art Social philosophy and political philosophy Feminist philosophy Anarchism Marxism Philosophical traditions and schools African philosophy Aristotelianism Analytic philosophy

Continental philosophy Eastern philosophy Feminist philosophy History of philosophy Ancient philosophy Medieval philosophy Modern philosophy Contemporary philosophy Logic Philosophical logic Mathematical logic Applied philosophy Philosophy of Artificial Intelligence and Cognitive Science Philosophy of education Philosophy of history Philosophy of religion Philosophy of language Philosophy of law Philosophy of mathematics Philosophy of music Philosophy of science Philosophy of social science Philosophy of Physics Philosophy of Biology Philosophy of Chemistry Philosophy of economics Philosophy of Psychology Philosophy of engineering Systems philosophy

Religion

See also List of religions

Abrahamic religions Christianity Christian Theology Bibliology Hermeneutics Theology Proper Christology Pneumatology Theological anthropology Soteriology Nomology Ecclesiology Eschatology Islam / Islamic studies Judaism / Jewish studies Indian religions Buddhism Hinduism Jainism Sikhism

Taoic religions Chinese folk religion Confucianism Shinto Taoism Other religions African religions Ancient Egyptian religion Native American religions Gnosticism Esotericism New religious movements Sumerian religion Zoroastrianism Atheism and Humanism Comparative religion Mythology and Folklore

Visual arts

Art history Calligraphy Connoisseurship Creative arts Drawing Fine arts Painting

Photography Mixed Media Printmaking Studio art Sculpture Art conservation

Social sciences

Anthropology

See also Branches of anthropology

Biological anthropology Forensic anthropology Gene-culture coevolution Human behavioral ecology Human evolution Medical anthropology Paleoanthropology Population genetics Primatology Anthropological linguistics Synchronic linguistics (or Descriptive linguistics) Diachronic linguistics (or Historical linguistics) Ethnolinguistics Sociolinguistics

Cultural anthropology Anthropology of religion Economic anthropology Ethnography Ethnohistory Ethnology Ethnomusicology Folklore Mythology Political anthropology Psychological anthropology

Archaeology

See also Branches of archaeology

Classical archaeology Egyptology Experimental archaeology Maritime archaeology

Near Eastern archaeology Paleoanthropology Prehistoric archaeology

Area studies

See also Branches of area studies

American studies Appalachian studies African studies Asian studies Canadian studies Celtic studies European studies German studies

Indology (Indian studies) Iranian studies Japanology (Japanese studies) Latin American studies Sinology (Chinese studies) Scandinavian studies Slavic studies

Cultural and ethnic studies

Asian studies Asian American studies Black studies or African American studies Chicano studies

Childhood studies Latino studies Native American studies Persian studies

Economics

Agricultural economics Behavioural economics Bioeconomics Computational economics Consumer economics Development economics Ecological economics Econometrics Economic geography Economic history Economic sociology Economic systems Energy economics Entrepreneurial economics Environmental economics Evolutionary economics Experimental economics Feminist economics Financial economics Game theory Green economics Growth economics Human development theory

Industrial organization Information economics Institutional economics International economics Islamic economics Labor economics Law and economics Macroeconomics Managerial economics Mathematical economics Microeconomics Monetary economics Neuroeconomics Political economy Public finance Public economics Real estate economics Resource economics Socialist economics Socioeconomics Transport economics Welfare economics

Gender and sexuality studies

Feminine psychology Gender studies/Gender theory Heterosexism Human sexual behavior Human sexuality Masculine psychology

Men's studies Queer studies/Queer theory Sex education Sexology Women's studies

Geography

See also Branches of geography

Cartography Human geography Cultural geography Feminist geography Economic geography Development geography Historical geography Time geography Political geography & geopolitics Military geography Strategic geography Population geography Social geography Behavioral geography Children's geographies Health geography Tourism geography Urban geography

Environmental geography Physical geography Biogeography Climatology Palaeoclimatology Coastal geography Geomorphology Geodesy Hydrology/Hydrography Glaciology Limnology Oceanography Landscape ecology Palaeogeography Regional geography

Political science

See also Branches of political science

American politics Canadian politics Civics Comparative politics Geopolitics (Political geography) International relations International organizations Peace and conflict studies Policy studies

Political behavior Political culture Political economy Political history Political philosophy Psephology Public administration Nonprofit administration Non-governmental organization (NGO) administration Public policy

Psychology

See also Branches of psychology, Cognitive science, Affective science, and Behavioural science

Abnormal psychology Applied psychology Biological psychology Clinical psychology Cognitive psychology Community psychology Comparative psychology Consumer psychology Counseling psychology Cultural psychology Differential psychology Developmental psychology Educational psychology Evolutionary psychology Experimental psychology Forensic psychology Health psychology Legal psychology

Media psychology Medical psychology Military psychology Neuropsychology Occupational health psychology Organizational psychology Parapsychology Personality psychology Political psychology Positive psychology Psychometrics Psychology of religion Psychophysics Quantitative psychology School psychology Social psychology Sport psychology

Sociology

See also Branches of sociology

Applied sociology Political sociology Public sociology Social engineering Leisure studies Collective behavior Social movements Community informatics Social network analysis Comparative sociology Conflict theory Cultural studies Criminology/Criminal justice Demography/Population Environmental sociology Feminist sociology Future studies Human ecology Interactionism Phenomenology Ethnomethodology Symbolic interactionism Social constructionism Medical sociology Military sociology Organizational studies Science studies/Science and technology studies Sexology Social capital

Social control Pure sociology Social economy Social philosophy Social psychology Social policy Social research Computational sociology Economic sociology/Socioeconomics Economic development Social development Sociology of culture Sociology of deviance Sociology of education Sociology of gender Sociology of the family Sociology of knowledge Sociology of law Sociology of religion Sociology of sport Sociology of work Social theory Social stratification Sociological theory Sociobiology Sociocybernetics Sociolinguistics Urban studies or Urban sociology/Rural sociology Visual sociology

Natural sciences

Space sciences

See also Branches of astronomy

Astrobiology Astronomy Observational astronomy Gamma ray astronomy Infrared astronomy Microwave astronomy Optical astronomy Radio astronomy UV astronomy X-ray astronomy Astrophysics Gravitational astronomy Black holes

Interstellar medium Numerical simulations in Astrophysical plasma Galaxy formation and evolution High-energy astrophysics Hydrodynamics Magnetohydrodynamics Star formation Physical cosmology Stellar astrophysics Helioseismology Stellar evolution Stellar nucleosynthesis

Earth sciences

See also Branches of earth sciences

Edaphology Environmental science Environmental chemistry Gemology Geodesy Geography Geology Geochemistry Geomorphology Geophysics Glaciology Hydrogeology Hydrology

Meteorology Mineralogy Oceanography Pedology Paleontology Paleobiology Planetary science Sedimentology Soil science Speleology Tectonics

Life sciences

See also Branches of life sciences

Biochemistry Bioinformatics Biology Aerobiology Anatomy Comparative anatomy Human anatomy Botany Ethnobotany Phycology Cell biology Chronobiology Cryobiology Developmental biology Embryology Ecology Human ecology Landscape ecology Genetics Behavioural genetics Endocrinology Evolutionary biology Human biology Marine biology Microbiology Molecular biology Nutrition Neuroscience Behavioral neuroscience

Paleobiology Paleontology Virology Molecular virology Xenobiology Zoology Animal communications Cryptozoology Entomology Ethology Herpetology Ichthyology Oology Ornithology Primatology Zootomy Biophysics Limnology Linnaean taxonomy Mycology Parasitology Pathology Physiology Human physiology Exercise physiology Systematics (Taxonomy) Teratology

Chemistry

See also Branches of chemistry

Analytical chemistry Biochemistry Cheminformatics Computational chemistry Materials science Mathematical chemistry

Quantum chemistry Inorganic chemistry Organic chemistry Physical chemistry Theoretical chemistry Interface and colloid science

Physics

See also Branches of physics

Acoustics Astrophysics Atomic, molecular, and optical physics Biophysics Theoretical physics Computational physics Condensed matter physics Cryogenics Electromagnetism Elementary particle physics Fluid dynamics Geophysics Mathematical physics Medical physics

Materials science Mechanics Molecular physics Nuclear physics Newtonian dynamics Optics Plasma physics Quantum physics Solid state physics Solid mechanics Statistical mechanics Vehicle dynamics Thermodynamics Applied Physics

Formal sciences

Computer sciences

See also Branches of computer science and ACM Computing Classification System

Theory of computation Automata theory (Formal languages) Computability theory Computational complexity theory Concurrency theory Algorithms Randomized algorithms Distributed algorithms Parallel algorithms Data structures Computer architecture VLSI design Operating systems Computer communications (networks) Information theory Internet, World wide web Wireless computing (Mobile computing) Ubiquitous computing Cloud computing Computer security and reliability Cryptography Fault-tolerant computing Distributed computing Grid computing Parallel computing High-performance computing Quantum computing Computer graphics Image processing Scientific visualization Computational geometry Software engineering Formal methods (Formal verification) Programming languages Programming paradigms Object-oriented programming Functional programming Concurrent programming Program semantics Type theory Compilers Information systems (Business informatics) Information technology Management information systems Health informatics Human-computer interaction

Information science Data management Data mining Database Relational database Distributed database Object database Information retrieval Information management Knowledge management Multimedia, hypermedia Artificial intelligence Cognitive science Automated reasoning Machine learning Artificial neural network Support vector machine Natural language processing (Computational linguistics) Computer vision Expert systems Robotics Computing in Mathematics, Natural sciences, Engineering and Medicine Numerical analysis Algebraic (symbolic) computation Computational number theory Computational mathematics Scientific computing (Computational science) Computational biology (bioinformatics) Computational physics Computational chemistry Computational neuroscience Computer-aided engineering Finite element analysis Computational fluid dynamics Computing in Social sciences, Arts and Humanities, Professions Computational economics Computational sociology Computational finance The Digital Humanities (Humanities computing) Computer and society History of computer hardware History of computer science Humanistic informatics Community informatics

Logic

Mathematical logic Set theory Proof theory Model theory Recursion theory Modal logic Intuitionistic logic

Philosophical Logic Modal logic Deontic logic Doxastic logic Logical reasoning Logic in computer science Programming language semantics Formal methods (Formal verification) Type theory Logic programming Multi-valued logic Fuzzy logic

Mathematics

See also Branches of mathematics and AMS Mathematics Subject Classification

Algebra Group theory Group representation Ring theory Commutative algebra Noncommutative algebra Field theory Linear algebra (Vector space) Multilinear algebra Lie algebra Associative algebra Non-associative algebra Universal algebra Homological algebra Differential algebra Lattice theory (Order theory) Representation theory K-theory Category theory Topos theory Analysis Real analysis Calculus Complex analysis Functional analysis Operator theory Non-standard analysis Harmonic analysis Fourier analysis p-adic analysis Ordinary differential equations Partial differential equations Probability theory Measure theory Integral geometry Ergodic theory Stochastic process Geometry and Topology General topology Algebraic topology Geometric topology Differential topology Algebraic geometry Differential geometry Projective geometry Affine geometry Non-Euclidean geometry Convex geometry Discrete geometry Integral geometry Noncommutative geometry

Number theory Analytic number theory Algebraic number theory Geometric number theory Logic and Foundations of mathematics Set theory Proof theory Model theory Recursion theory Modal logic Intuitionistic logic Applied mathematics Statistics Mathematical statistics Econometrics Actuarial science Demography Approximation theory Numerical analysis Operations research Optimization (Mathematical programming) Linear programming Dynamic programming Assignment problem Decision analysis Inventory theory scheduling Real options analysis Systems analysis Stochastic processes Optimal maintenance Dynamical systems Chaos theory Fractal geometry Mathematical physics Quantum mechanics Quantum field theory Quantum gravity String theory Statistical mechanics Theory of computation Computational complexity theory Information theory Cryptography Combinatorics Coding theory Graph theory Game theory

Statistics

Computational statistics Data mining Regression Simulation Bootstrap (statistics) Design of experiments Block design and Analysis of variance Response surface methodology Sample Survey Sampling theory

Statistical modelling Biostatistics Epidemiology Multivariate analysis Structural equation model Time series Reliability theory Quality control Statistical theory Decision theory Mathematical statistics Probability Survey methodology

Systems science

Complex systems Cybernetics Control theory Control engineering Control systems Dynamical systems Operations research

Systems dynamics Systems engineering Systems analysis Systems theory Developmental systems theory General systems theory Mathematical system theory

Professions and Applied sciences

Agriculture

Agroecology Agronomy Animal husbandry (Animal science) Beekeeping (Apiculture) Agrology Entomology Agricultural economics Agricultural engineering Biological systems engineering Food engineering

Aquaculture Enology Food science Horticulture Hydrology Plant science Pomology Viticulture

Architecture and design

Architecture and related design Architecture Urban planning (urban design) Interior design (interior architecture) Landscape architecture (landscape planning) Historic preservation

Industrial design (product design) Ergonomics Game design* Toy and amusement design* Fashion design Textile design Visual communication Graphic design Type design User interface design Technical drawing

Business

Accounting scholarship Business administration Business analysis Business ethics E-Business Entrepreneurship Finance Industrial and labor relations Collective bargaining Human resources

Organizational studies Labor economics Labor history Information systems Business Law International Trade Marketing Risk management and insurance Systems science Purchasing

Divinity

Canon law Church history Field ministry Pastoral counseling Pastoral theology Religious education techniques Homiletics Liturgy Sacred music

Scriptural study and languages Biblical Hebrew Biblical studies/Sacred Scripture New Testament Greek Latin Old Church Slavonic Theology Dogmatic theology Ecclesiology Sacramental theology Systematic theology

Education

Consumer education Critical pedagogy Curriculum and instruction Elementary education Secondary education Higher education Mastery learning Cooperative learning Agricultural education Art education Bilingual education Chemistry education Counselor education Language education Legal education Mathematics education Medical education Military education and training

Music education Nursing education Peace education Physical education/Sports coaching Physics education Reading education Religious education Science education Special education Sex education Sociology of education Technology education Vocational education Educational leadership Educational philosophy Educational psychology Educational technology Distance Education

Engineering

See also Branches of engineering

Aerospace engineering Agricultural engineering Food engineering Architectural engineering Bioengineering Biomechanical engineering Biomedical engineering Chemical engineering Civil engineering Geotechnical engineering Engineering Geology Earthquake engineering Highway engineering Transportation engineering Computer engineering Control systems engineering Ecological engineering Electrical engineering Electronic engineering Instrumentation engineering Engineering physics Environmental engineering Industrial engineering

Materials engineering Ceramic engineering Metallurgical engineering Polymer engineering Mechanical engineering Manufacturing engineering Mining engineering Nanoengineering Nuclear engineering Ocean engineering Marine engineering Naval architecture Optical engineering Quality assurance engineering Petroleum engineering Safety engineering Software engineering Structural engineering Systems engineering Telecommunications engineering Vehicle engineering Automotive engineering

Environmental studies and Forestry

Environmental management Coastal management Fisheries management Land management Natural resource management Wildlife management

Environmental policy Recreation ecology Silviculture Sustainable development Toxicology

Family and consumer science

Consumer education Housing* Interior design

Nutrition Foodservice management* Textiles*

Health sciences

See also Branches of medicine

Alternative medicine Acupuncture Clinical laboratory sciences Clinical biochemistry Cytogenetics Cytohematology Cytology Haemostasiology Histology Immunology Microbiology Molecular genetics Parasitology Dentistry Dental hygiene and epidemiology Dental surgery Endodontics Orthodontics Oral and maxillofacial surgery Periodontics Prosthodontics Implantology Nursing Nursing theory Midwifery Nutrition and dietetics Optometry Orthoptics Physiotherapy Occupational therapy Speech and language pathology Medicine Anesthesiology Regional anesthesia Pain medicine Preventive medicine Cardiology Emergency medicine Medical toxicology Endocrinology Diabetology Epidemiology Forensic science Geriatrics Gynaecology Hematology Infectious disease Internal medicine (general medicine)

Nephrology Neurology Neurosurgery Obstetrics Oncology Ophthalmology Orthopedic surgery Hand surgery Foot and ankle surgery Sports medicine Joint replacement Shoulder surgery Otolaryngology Pathology Pediatrics Podiatry Primary care General practice Public health Psychiatry Addiction medicine Radiology Recreation therapy Rehabilitation medicine Respiratory medicine Pulmonology Sleep medicine Rheumatology Sports medicine Surgery Bariatric surgery Cardiothoracic surgery Neurosurgery Plastic surgery Traumatology Urology Andrology Pharmaceutical sciences Pharmacy Behavioral medicine Clinical psychology Health psychology Medical psychology Counseling psychology Veterinary medicine Physical fitness Group Fitness / aerobics Personal fitness training Kinesiology / Exercise Science / Human Performance

Human physical performance and recreation*

Biomechanics / Sports Biomechanics Sports coaching Dance Ergonomics Physical fitness Group Fitness / aerobics Personal trainer / Personal fitness training Game design* Exercise physiology Kinesiology / Exercise Science / Human Performance

Leisure studies Physical education / Pedagogy Sociology of sport Sexology Sports journalism / sportscasting Sport management Athletic director Sport psychology Sports medicine Athletic training Toy and amusement design*

Journalism, media studies and communication

Journalism Broadcast journalism Literary journalism New media journalism Print journalism Sports journalism / sportscasting Media studies (Mass media) Newspaper Magazine Radio Television Television studies* Internet

Communication studies Animal communications Information theory Intercultural communication Advertising Communication design Marketing Mass communication Translation Propaganda Public relations Technical writing Nonverbal communications Speech communications

Law

Canon law Comparative law Constitutional law Civil law Admiralty law Animal law/Animal rights Corporations Civil procedure Contracts Environmental law International law Labor law

Paralegal studies Property law Tax law Torts Criminal law Criminal procedure Criminal justice Police science Forensics Islamic law Jewish law Jurisprudence (Philosophy of Law)

Library and museum studies

Archival science Bibliometrics Citation analysis Informatics

Information architecture Museology Museum administration

Military sciences

Amphibious warfare Artillery Campaigning Military engineering Doctrine Game theory Leadership Logistics Military history Military intelligence

Military law Military medicine Naval science Naval engineering Naval tactics Naval architecture Weapons systems Strategy Tactics Naval tactics

Public administration

Corrections Conservation biology Criminal justice Emergency management Fire safety (Structural fire protection) Fire ecology (Wildland fire management) Governmental affairs International affairs Official statistics Peace and conflict studies

Police science Public administration Nonprofit administration Non-governmental organization (NGO) administration Public policy Education policy Environmental policy Fiscal policy Health policy Trade policy Defense policy

Social work

Child welfare Community practice Community organizing Social policy

Corrections Gerontology Medical social work Mental health School social work

Transportation

Highway safety Infographics Intermodal transportation studies

Marine transportation Port management Operations research Mass transit

See also

• Academia
• Academic genealogy
• Curriculum
• Fields of science
• Interdisciplinarity
• Classification of Instructional Programs
• Joint Academic Classification of Subjects
• List of education topics
• List of fields of doctoral studies
• Transdisciplinary studies

Notes

References

• Andrew Abbott, Chaos of Disciplines University Of Chicago Press 2001 ISBN 0226001016
• Alexandra Oleson & John Voss (eds) The Organization of Knowledge in Modern America, 1860-1920 Johns Hopkins University Press 1979 ISBN 0801821088

External links

• Classification of Instructional Programs (CIP 2000): Developed by the U.S. Department of Education's National Center for Education Statistics to provide a taxonomic scheme that will support the accurate tracking, assessment, and reporting of fields of study and program completions activity.
• Complete JACS (Joint Academic Classification of Subjects) from Higher Education Statistics Agency (HESA) in the United Kingdom
• Australian and New Zealand Standard Research Classification (ANZSRC 2008) (web-page) Chapter 3 and Appendix 1: Fields of research classification.