In the February 1989 Word Ways, I examined various word networks based on words from the Official Scrabble Players Dictionary (OSPD). To refresh the reader's memory, a word network consists of a set of words of a given length that can be joined by word ladders (single-letter changes). Each pair of words in a word network can be connected by a minimum-length ladder (one which cannot be reduced by any alternative ladder).
Gordon, Leonard J.
"More Word Network Spasns in the OSPD,"
Word Ways: Vol. 23
, Article 10.
Available at: http://digitalcommons.butler.edu/wordways/vol23/iss3/10