This volume is a corpus study of the construet of accuracy by learners

of English as a Foreign Language based on the International Corpus

of Learner English. Accuracy is analysed from a developmental point

of view at four consecutive levels of language proficiency (B1, B2, C1,

C2), thereby providing insights into areas of progress, stabilisation

and regression. Written within a computer-aided error analysis

research framework, this volume offers valuable information about the

development of more than forty error types in a wide variety of domains

such as grammar, lexis, lexico-grammar, spelling and punctuation. It

provides important methodological considerations for developmental

learner corpus research, presents abundantly illustrated analyses

of authentic learner errors as well as suggestions for improving the

descriptors of the Common European Framework of Reference for

Languages.