| Subject | English | Basque |
| math. | ballot theory | eskrutinio teoria |
| math. | catastrophe theory | hondamendiaren teoria |
| math. | category theory | kategoria teoria |
| math. | central place theory | kokaleku zentral teoria |
| math. | decision theory | erabakien teoria |
| environ. | economic theory The study of relationships in the economy. Its purpose is to analyze and explain the behaviour of the various economic elements. The body of economic theory can be divided into two broad categories, positive theory and welfare theory. Positive theory is an attempt to analyze the operation of the economy without considering the desirability of its results in terms of ultimate goals. Welfare theory is concerned primarily with an evaluation of the economic system in terms of ethical goals which are not themselves derived from economic analysis | ekonomia-teoria |
| math. | frequency theory of probability | maiztasuna probabilitate teoria |
| math. | fuzzy set theory | multzo lauso-teoria |
| stat. | game theory | jokoen teoria |
| math. | game theory | jokoen teoria |
| math. | game theory | joko teoria |
| math. | higher-order asymptotic theory | goi-ordena asintotiko teoria |
| math. | information theory | informazloaren teoria |
| math. | Lexis theory | Lexikoa teoria |
| math. | Neyman-Pearson theory | Neyman-Pearson teoria |
| math. | renewal theory | berritzeko teoria |
| environ. | systems theory The science concerned with the general study of structures and behaviours of systems which may be applicable in different branches of learning | sistema-teoria |
| environ. | theory of money A coherent group of general propositions about the supply and demand of money, interest rates, the flow of money's influence on the overall economy or the policies that should be adopted by institutions controlling the money supply | diruaren teoria |
| environ. | theory of the environment A structured simulation or explanation based on observation, experimentation and reasoning that seeks to demonstrate, characterize or explain the actions and interactions of the total surrounding conditions of a given system | ingurugiroaren teoria |
| environ. | theory of the welfare state A political conception of government in a capitalist economy where the state is responsible for insuring that all members of society attain a minimum standard of living through redistribution of resources, progressive taxation and universal social programs, including health care and education | ongizate-estatuaren teoria |