“The first step in knowing a word is simply to recognize that it is a word. Paul Meara and his colleagues (2005) have developed tests that take advantage of this fact. Some of these tests take the form of word lists, and learners are instructed to check ‘yes’ or ‘no’ according to whether or not they know the word. Each list also includes some items that look like English words but are not. The number of real words that the learner identifies is adjusted for guessing by a factor that takes account of the number of non-words that are also chosen. Such a procedure is more effective than it might sound. A carefully constructed list can be used to estimate the vocabulary size of even advanced learners. For example, if shown the following list: ‘frolip, laggy, scrule, and albeit’, a proficient speaker of English would know that only one of these words is a real English word, albeit a rare and somewhat odd one. On the other hand, even proficient speakers might recognize none of the following items: ‘goniometer, micelle, laminitis, throstle’. Even our computer’s spell-checker rejected two out of four, but all are real English words, according to the New Oxford Dictionary of American English.”