| Subject | English | Catalan |
| math. | asymptotically efficient estimator | estimador asimptòticament eficient |
| math. | efficient estimator | estimador eficient |
| comp., MS | Efficient File Storage | Emmagatzematge eficient de fitxers (A storage method in which a file is split into pieces that are stored and updated separately, and streamed together when a user requests the file) |
| math. | most efficient estimator | estimador de màxima eficiència |