Learning L2 German vocabulary through reading: the effect of three enhancement techniques compared

This study investigated three techniques designed to increase the chances that second language (L2) readers look up and learn unfamiliar words during and after reading an L2 text. Participants in the study, 137 college students in Belgium (L1 = Dutch, L2 = German), were randomly assigned to one of four conditions, forming combinations of two between-subject factors: ± prereading test announcement and ± postreading vocabulary task. Comprehension questions were used to direct participants' attention to half of the 16 target words in this study, creating the within-subject factor (word relevance). Participants accomplished the experimental tasks at computers. They could look up the meaning of unfamiliar words in an online dictionary. The dependent variables are the following: use of online dictionary during reading, performance on a word-form recognition test, and performance on two word-meaning recall tests (immediate and delayed). Test announcement and word relevance substantially prompted participants to use the online dictionary more. Only test announcement and vocabulary task (not word relevance) affected performance in the word recognition test positively. Both word relevance and postreading vocabulary task substantially affected word retention in the recall posttests. These findings, together with those of the studies reviewed, provide robust evidence that the low incidence of vocabulary acquisition through reading ("input only") can be substantially boosted by techniques that make students look up the meaning of unknown words, process their form-meaning relationship elaborately, and process them again after reading ("input plus").