In mailing back and forth with one of the researchers over at the Max Planck Institute, there was some confusion over the use of the term unique words in the Lexical Diversity tool. Unique words are not hapax legomena, which is the term in corpus linguistics for words that only occur once. Unique words are simply types and count up to the number of different words in a text. A word might occur once, twice or twenty times, but in all three cases, it would count as one unique word. This measure is also used for calculating the type-token-ratio. As the researcher was interested in how many words occur only once in a text, I've added this count. You can use the new feature here right away!
Hapax legomena in the Lexical Diversity tool
