Applied research: Original investigation undertaken to acquire new knowledge; directed primarily, however, toward a specific, practical aim or objective (OECD 2015).

Basic research: Experimental or theoretical work undertaken primarily to acquire new knowledge of the underlying foundations of phenomena and observable facts, without any particular application or use in view (OECD 2015).

Business sector: Consists of both private enterprises (regardless of whether they are publicly listed or traded) and government-controlled enterprises that are engaged in market production of goods or services at economically significant prices. Nonprofit entities, such as trade associations and industry-controlled research institutes, are also classified in the business sector (OECD 2015).

East and Southeast Asia: Includes China, Indonesia, Japan, South Korea, Malaysia, Philippines, Singapore, Taiwan, Thailand, and Vietnam.

European Union (EU-27): Twenty-seven member nations: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, and Sweden.

Experimental development: Systematic work, drawing on knowledge gained from research and practical experience and producing additional knowledge, which is directed to producing new products or processes or to improving existing products or processes (OECD 2015).

First university degree: A terminal undergraduate degree program; these degrees are classified within level 6 (bachelor’s degree or equivalent) or as “long first degrees” within level 7 (master’s degree or equivalent) in the 2011 International Standard Classification of Education.

Foreign-born workers: Those born outside of the United States, regardless of citizenship. Foreign-born workers can be U.S. citizens or permanent residents.

Government sector: Consists of all federal, state, and local governments, except those that provide higher education services, and all nonmarket, nonprofit institutions controlled by government entities that are not part of the higher education sector. This sector excludes public corporations, even when all of the equity of such corporations is owned by government entities. Public enterprises are included in the business sector (see Business sector) (OECD 2015).

Higher education sector: Consists of all universities, colleges of technology, and other institutions providing formal tertiary education programs, whatever their source of finance or legal status, as well as all research institutes, centers, experimental stations, and clinics that have their R&D activities under the direct control of, or that are administered by, tertiary education institutions (OECD 2015).

Highly cited article (HCA): An HCA ratio provides an indication of scientific impact (Waltman, van Eck, and Wouters 2013). The HCA ratio for a region, country, or economy is calculated as the share of all articles published in a given year by authors with institutional addresses within that region, country, or economy that fall within the top 1% by citation count of all articles published that year, measured for each research field. The HCA ratio is indexed to 1.00, so a region, country, or economy whose authors produce highly cited articles at the expected (i.e., global average) rate has an HCA ratio of 1.00—that is, 1% of the region’s, country’s, or economy’s articles are among the top 1% of the world’s HCAs. A region, country, or economy with an HCA ratio greater than 1.00 is producing a disproportionately high level of articles with exceptional scientific impact, whereas a region, country, or economy whose authors produce relatively fewer influential articles will have an HCA ratio below 1.00.

Innovation: A new or improved product or process (or combination thereof) that differs significantly from the unit’s previous products or processes and that has been made available to potential users (product) or brought into use by the unit (process). The unit is a generic term to describe the actor responsible for innovations. It refers to any institutional unit in any sector, including households and their individual members, according to the Oslo Manual 2018 (OECD, Eurostat 2018). 

International patents: Original patents issued by any international jurisdiction, adjusted to count only the first issuance of a series or family of related patents. The unit of measurement is a patent family that shares a single original invention in common. All subsequent patents in a family refer to the first patent filed, or priority patent, and the indicator provides an unduplicated count of original or priority patents in any individual jurisdiction. The organization of these international patents around a single initial invention means that there may be fewer international patents than individual patents. 

Invention: Any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof (USPTO 2023).

Knowledge- and technology-intensive (KTI) industries: Industries classified by the Organisation for Economic Co-operation and Development as high R&D intensive and medium-high R&D intensive industries based on R&D intensity (see R&D intensity).

Middle-skill occupations: Occupations that require a high level of scientific and technical knowledge, although these occupations do not typically require a bachelor’s degree for entry. Middle-skill occupations are primarily in construction trades, installation, maintenance, and production.

Open access (OA): OA refers to peer-reviewed publications that are accessible online to any reader without requiring a journal subscription or other fees from readers (Piwowar et al. 2018). Several commonly defined types of OA have been adopted for the purposes of this analysis. Gold OA denotes articles published in journals that are entirely OA as a matter of journal policy. Hybrid OA refers to articles appearing in closed-access journals where the authors have paid a fee to make the article OA. Bronze OA denotes articles in closed-access journals that become OA after an embargo period of closed access or articles that appear available as OA despite lacking the license information to guarantee OA in the long term. Green OA denotes articles that are self-archived by authors in OA repositories, which are often maintained and administered by universities or other institutions.

Patent Cooperation Treaty applications: An international agreement that allows entities to seek patent protection for an invention simultaneously in each of a large number of countries by filing an “international” patent application. Such an application may be filed by anyone who is a national or a resident of a contracting state (WIPO 2023). Patent Cooperation Treaty applications include Patent and Trademark Office (USPTO) patent applications (see USPTO patent).

Patenting intensity: Number of patents per population in a geographic location.

Patent and Trademark Office (USPTO) patent: As defined by the USPTO, a property right granted by the U.S. government to an inventor “to exclude others from making, using, offering for sale, or selling the invention throughout the United States or importing the invention into the United States” for a limited time in exchange for public disclosure of the invention when the patent is granted. Available at https://www.uspto.gov/learning-and-resources/glossary. Accessed 1 August 2023. USPTO applications are included in Patent Treaty Cooperation applications (see Patent Cooperation Treaty applications).

Purchasing power parity (PPP): The price of a common basket of goods and services in each participating economy, measuring what an economy’s local currency can buy in another economy (World Bank 2023). PPPs convert different currencies to a common currency while adjusting for differences in price levels between economies, and thus they enable direct comparisons of R&D expenditures across countries.

Research and development (R&D) funding (funders): Expenditures (or those that use expenditures) to pay the costs of R&D performance. For example, the federal government provides funding to laboratories at higher education institutions to perform R&D at the laboratories. R&D funders may differ from R&D performers (see R&D performance).

Research and development (R&D) intensity: A measure of R&D expenditures relative to size, production, financial, or other characteristics for a given R&D-performing unit (e.g., country, sector, or company). Examples include R&D-to-gross domestic product (GDP) ratio used in R&D cross-national comparisons and R&D-to-value-added output ratio used to classify industries as knowledge and technology intensive.

Research and development (R&D) performance (performers): Intramural expenditures (or those that use intramural expenditures) to conduct R&D. For example, laboratories at higher education institutions perform R&D with funding from the federal government. R&D performers may differ from R&D funders (see R&D funding).

Research and (experimental) development (R&D): Creative and systematic work undertaken to increase the stock of knowledge—including knowledge of humankind, culture, and society—and its use to devise new applications of available knowledge (OECD 2015).

Science and engineering (S&E) fields: Degrees awarded in the following fields: agricultural sciences and natural resources; biological and biomedical sciences; computer and information sciences; engineering; geosciences, atmospheric sciences, and ocean sciences; mathematics and statistics; multidisciplinary and interdisciplinary sciences; physical sciences; psychology; and social sciences. At the doctoral level only, health sciences are also included in S&E fields of study because at this level these fields are more likely to be research oriented rather than practitioner oriented.

Science and engineering (S&E) occupations: Occupations in the following five major categories: (1) computer and mathematical scientists; (2) biological, agricultural, and environmental life scientists; (3) physical scientists; (4) social scientists; and (5) engineers.

Science and engineering (S&E)-related occupations: These occupations require science and technology expertise but are not part of the five major categories of the S&E occupations. S&E-related occupations include these four minor occupations: (1) health, (2) S&E managers, (3) S&E precollege teachers, and (4) technologists and technicians.

Science, technology, engineering, and mathematics (STEM) occupations: A subset of the U.S. workforce comprised of S&E, S&E-related, and STEM middle-skill occupations (see S&E, S&E-related, and Middle-skill occupations).

Skilled technical workforce (STW): Workers in STEM occupations (S&E, S&E-related, and middle-skill occupations) who do not have an educational attainment of a bachelor’s degree or higher.

Utility patent: Intellectual property protection for a potentially useful, previously unknown, and nonobvious invention.

Value-added output: A measure of industry production that is the amount contributed by the country, industry, or other entity to the value of the good or service. It excludes the country's, industry's, or other entity's purchases of domestic and imported supplies and inputs from other countries, industries, firms, and other entities.

ABS: Annual Business Survey

ACS: American Community Survey

BEA: Bureau of Economic Analysis

DHS: Department of Homeland Security

DOD: Department of Defense

DOE: Department of Energy

EBD: European Patent Bibliographic Data

EU-27: European Union

GDP: gross domestic product

GSS: Survey of Graduate Students and Postdoctorates in Science and Engineering

HCA: highly cited article

HHS: Department of Health and Human Services

ICE: Immigration and Customs Enforcement

IPEDS: Integrated Postsecondary Education Data System

IT: information technology

KTI: knowledge and technology intensive

MOE (China): Ministry of Education (China)

MOE (India): Ministry of Education (India)

MSTI: Main Science and Technology Indicators

NAEP: National Assessment of Educational Progress

NASA: National Aeronautics and Space Administration

NBS (China): National Bureau of Statistics (China)

NCES: National Center for Education Statistics

NCSES: National Center for Science and Engineering Statistics

NIH: National Institutes of Health

NSB: National Science Board

NSCG: National Survey of College Graduates

NSF: National Science Foundation

NSTC: National Science and Technology Council

OA: open access

OECD: Organisation for Economic Co-operation and Development

PPP: purchasing power parity

R&D: research and (experimental) development

S&E: science and engineering

SEVIS: Student and Exchange Visitor Information System

STEM: science, technology, engineering, and mathematics

STI: science, technology, and innovation

STW: skilled technical workforce

TIMSS: Trends in International Mathematics and Science Study

UK: United Kingdom

USDA: Department of Agriculture

USPTO: Patent and Trademark Office

WIPO: World Intellectual Property Organization