Several researchers have argued that vocabulary plays a major part in reading proficiency. Thus, Grabe (1991) stresses the important role of vocabulary as predictor of overall reading ability, and Nation (1990) states that effective L2 /FL instruction should also concentrate on cultivating vocabulary (both cited in Anderson, 1999: 25). Chanier and Selva also stress the fact that vocabulary knowledge is a key factor in reading comprehension (1998: 489) and so does Groot (2000), who argues that functional L2 reading proficiency requires mastery of a considerably large number of words.