· It is the problem of whether a general descriptive dictionary should give the historical information about a word.
· For the purpose of a dictionary, which must not be too massive, selection between scientific and technical terms is also a very important task.
· It is a debatable point whether a unilingual explanatory dictionary should try to cover all the words of the language, including neologisms, nonce-word, slang, etc. and note with impartial accuracy all the words actually used by English people;
As the great English lexicographer of the 18th century Samuel Johnson used to think, it should be preceptive, and prohibitive. Dictionary-makers should attempt to improve and stabilize the English vocabulary and advise the readers on preferable usage. A distinctly modern criterion in selection of entries is the frequency of the words to be included.