| Subject | English | Catalan |
| math. | asymptotic efficiency | eficiencia asimptòtica |
| math. | asymptotic relative efficiency | eficiència relativa asimptòtica |
| math. | Bahadur efficiency | eficiència de Bahadur |
| math. | Cramer-Rao efficiency | eficiència de Cramér-Rao |
| stat. | Cramér-Rao efficiency | eficiència de Cramér-Rao |
| environ. | economical-ecological efficiency The competency in performance in business matters involving the relation between financial and environmental principles | eficiència econòmico-ecològica |
| environ. | efficiency criterion Parameter or rule for assessing the competency in performance of production relative to the input of resources | criteri d'eficiència |
| math. | efficiency equivalence | equivalència d'eficiència |
| math. | efficiency factor | factor d'eficiència |
| math. | efficiency index | índex d'eficiència |
| environ. | efficiency level The ratio of output to input, usually given as a percentage | nivell d'eficiència |
| environ. | energy efficiency Refers to actions to save fuels by better building design, the modification of production processes, better selection of road vehicles and transport policies, the adoption of district heating schemes in conjunction with electrical power generation, and the use of domestic insulation and double glazing in homes | rendiment energètic |
| environ. | improvement of efficiency The beneficial development or progress in the volume of output that is achieved in terms of productivity and input, or in getting the maximum possible output from given or allocated resources | millora de l'eficiència |
| math. | local asymptotic efficiency | eficiència asimptòtica local |
| math. | Pitman efficiency | eficiència de Pitman |
| stat. | power efficiency | eficiència relativa (of a test, d'un estimador) |
| math. | power efficiency | eficiència relativa (d'una prova) |
| math. | relative efficiency of a test | eficiència relativa (d'una prova) |