The Revised Second Edition contains 355,000 words, phrases, and definitions, including biographical references and thousands of encyclopaedic entries.

The first editor, Judy Pearsall, wrote in the introduction that it is based on a modern understanding of language and is derived from a corpus of contemporary English usage.

The first edition was based on bodies of texts such as the British National Corpus and the citation database of the Oxford Reading Programme.

[citation needed] The Second Edition added over 3,000 new words, senses and phrases drawn from the Oxford English Corpus.

[citation needed] The third editions of both texts were published in 2010, and form the basis of the ongoing electronic versions of the dictionaries.