Lexical fields, semantic fields, semantic networks and lexical sets. Are these four terms for the same thing or are they different?
First of all - what are we talking about in general? All of these terms cover different lexical relationships. This may range from very general groupings, eg some of the words associated with Gardening would be : sow, prune, dig, plant, seedling, shears, trowel, compost, fertiliser, weedkiller, caterpillar etc etc to words which have a more specific relationship such as synonymy, antonymy, hyponymy, meronymy or collocation.
When you want to sort out which of the terms covers which of the relationships however, well - unfortunately, it depends who you read. For example, semantic field and lexical field are sometimes used with different meanings - semantic field referring to abstract mental concepts and lexical field referring to the words that expressed those concepts. McCarthy (1990:21) states : ...lexical fields are the realization (or flesh and bones, as it were) of the abstract notion of semantic fields...
Other writers, however, use the terms synonymously. Lyons (1977) uses the term semantic network (a term originally coming from psychology) for the "abstract concepts" and semantic field for the lexical relationships. As Corson (1995) points out : Since semantic field is only a lexical category, it is identical with the term lexical field as Lyons expresses it.
McCarthy also suggests that lexical field and lexical set differ in meaning. Discussing hyponymy and giving examples of co-hyponyms of the superordinate vehicle he states : The whole list of co-hyponyms ("car", "lorry", "bus", "motorcyle" etc) is called a lexical set . The larger groupings, such as all the words under the headings of "modes of transport" are usually called lexical fields. (op. cit. : 19) Notice the hedge there though, with the word usually.
But again, here's a quote that suggests that lexical sets and semantic fields are synonymous. Sets of lexical entries whose meanings have certain aspects in common form a "semantic field". (Bierwisch, in Lyons (ed) 1970 : 170) This would also suggest that Bierwisch adopts Lyons' idea that semantic field = lexical field. So in his terms we also now have semantic field = lexical field = lexical set.
Many writers avoid the terms completely, talking only about "lexical relationships". My own preference is that :
Semantic network = abstract psychological concepts
Semantic field = lexical field = general associations between words, as in the gardening example above.
Lexical set = specific relationships such as hyponomy, meronymy etc etc. (See the links above)
But - yer pays your money and yer takes your choice...
Bierwisch, M. in Lyons, J (ed.) (1970) New Horizons in Linguistics, Ch. 8
Corson, D.(1995) Using English Words, Kluwer Academic Publishers
Lyons, J. (1977) Semantics, Cambridge University Press
McCarthy, M. (1990) Vocabulary, Oxford University Press