The search for the meanings of words has become more sophisticated thanks to the publishers of learners' dictionaries. Daniel Monaghan examines the range of new content available on the CD-Roms that accompany the books and on publishers' websites

Learners' dictionaries are an essential tool for serious students and there has been fierce competition among publishers trying to make sure that their dictionary is the one that students choose. Each new edition boasts the most up-to-date words in the language and new features to help users become more proficient speakers. Today advanced level learners' dictionaries all come with CD-Roms that offer not just an alternative to searching through the printed page, but a wealth of new information and tools.

Hilary Nesi, professor in English language at Coventry University, England, has researched learner dictionary use. She says that dictionary software has the "potential to enable people to retrieve information in innovative ways, rather than simply looking up words in alphabetical order".

The current generation of dictionary CD-Roms offer multiple routes to words, including searching by synonym, pronunciation or even word origin. And once located, many programs allow users to hear the word being pronounced and record themselves pronouncing it for comparison.

Pearson highlights its newest audio tool available with the latest edition of the Longman Dictionary of Contemporary English: recordings of thousands of example sentences, allowing users to hear words spoken in context.

Several CD-Rom dictionaries now include detailed information about word origins. Joanna Turnbull, of Oxford University Press (OUP) ELT dictionaries, explains why the Oxford Advanced Learner's Dictionary is among them: "Our research showed that many students, particularly those from Vietnam and Thailand, liked having information about a word's origins and found this made the word more memorable."

Given the volume of information that dictionaries contain, it is not surprising that the CD-Rom accompanying the latest Macmillan English Dictionary, includes a button allowing users to reduce the level of detail on display. Stephen Bullon, dictionaries publisher at Macmillan, explains that a potential disadvantage of screen-based dictionaries is that "unlike a book you don't know how much information there is to come", so the button helps users to navigate more efficiently.

Learners who think that the time has come to dispense with the paper-based dictionary will be disappointed, however. Most of the main publishers only make their full CD-Rom content available when you buy the book, but that has not stopped them being more generous with other content and their websites are now a mine of information, activities and support for learners and teachers.

Several publishers offer free online versions of their main dictionaries, but withhold the extra tools and features found on the CD-Roms. A free resource available on the OUP website allows users to paste in a text and check what percentage of that text uses common words, giving a rough guide to its level. The program also highlights less common words, helping teachers to decide which words to pre-teach.

Cambridge University Press (CUP) is one of the first publishers to offer a subscription-only access to its dictionary content with its Cambridge Dictionaries Online Extra. Collins, meanwhile, is due to launch mycobuild.com, based on its new Collins Cobuild Advanced Learner's English Dictionary, as a subscription-only service later this year. This will allow users to tailor their searches to specific subject areas and have access to extra vocabulary sets. Elaine Higgleton, editorial director at Collins Language, explains: "The idea is that users select the sets that meet their needs and interests as learners; so someone studying medicine can opt for scientific and medical terminology."

As publishers wrestle over the fraught question of whether they can separate their book and online content and still make money, students are setting a new agenda. They are embracing mobile technology – from mobile phones to games consoles – and this is how they want to get access to online content. Several publishers have started to offer downloads of their dictionaries to run on hand-held computers and mobile phones. Last year CUP supplied definitions from its dictionary for an English language learning game for the Nintendo DS console.

But it is the pocket electronic dictionary (PED) that is giving most food for thought. Frowned on by many teachers as a distracting gimmick, PEDs have become very popular among learners who want to get an instant translation of difficult words into their first language. Nesi suggests that students often prefer PEDs because their small size allows the quick word search to remain a discreet act, unlike leafing through a dictionary.

Nesi believes that it is in the interests of students, teachers and publishers alike to understand exactly how learners are using or misusing PEDs, and this requires a willingness to bring them out from under the desk.