Abstract. We conducted a statistical analysis of several subsets of words from the Hoosier Mental Lexicon in order to examine some factors underlying the subjective familiarity ratings collected by Nusbaum, Pisoni, and Davis (1984). In this analysis, we grouped words into High-FAM (average familiarity rating greater than 6 on a 7-point scale), Mid-FAM (between 4.5 and 3.5), or Low-FAM (less than 2) sets, with primary interest being placed on the small set of Low-familiarity words (502 total), which were unknown to the majority of native listeners. This Low-FAM set consisted mainly of non-English borrowings, technical terms, and archaic words. These items received much higher ratings from Speech Research Laboratory staff, who we assume have greater language experience, showing that the familiarity scale employed is not continuous for very low ratings, especially in terms of the properties of Low-FAM words. As expected, High-FAM words were the majority and had greater frequency of occurrence, greater neighborhood density and frequency, and were shorter on average than Mid or Low words. However, when these sets of words were controlled for length, we found that High- and Mid-FAM words did not differ significantly in neighborhood density and