Wanna choose a dictionary?

Question

Im now considering to buy to dictionary. There are four choices: Oxford english dictionary, Oxford Advanced learner's dictionary, Cambridge Advanced learner's dictionary; Longman temporary dictionary. Can someone tell me which dictionary is the best? What are the differences between Oxford english dictionary and Oxford Advanced learner's dictionary?

My english level is: Im a master student in science. Can someone tell me which dicitonary is suitable for me? Is the online Oxford dictionary a good choice?

Im not native english speaker

Answer 1

The Oxford English Dictionary (in print) is 20 volumes and costs $895 (U.S.).
http://www.amazon.com/Oxford-English-Dictionary-Second-Set/dp/0198611862

Either you have deep pockets and lots of shelf space, or you're thinking of the wrong dictionary. The OED is typically owned by libraries and is more of a language research tool than a quickie reference book. You might be able to purchase a login for the online version of the OED, but that will be expensive and is probably not a one-time purchase. (Online subscriptions typically have to be renewed every year.)

The Oxford Advanced Learner's Dictionary is one volume, and only about $25 (U.S.)
http://www.amazon.com/Advanced-Learners-Dictionary-Current-English/dp/0194316068/sr=1-1/qid=1165255463/ref=pd_bbs_1/104-4257838-6471148?ie=UTF8&s=books

At any rate, all of the publishers you mention (Oxford, Cambridge and Longman) are respected reference book publishers. You should pick the dictionary that fits your budget and has the most amount of words. The dust jacket usually gives an approximation of how many words the dictionary covers.

Answer 2

The Oxford Advanced is what you want for personal use, the Cambridge is also good. Those dictionaries are meant for every day use by students and scholars. The Complete Oxford is for library use.