This research focused on the incidental learning of the meaning of new word forms occurring in a reading passage. In five experiments, a comparison was made of the retention effects of several ways to orient readers to the meaning of twelve new word forms ("targets"), occurring in a reading passage, containing otherwise simple vocabulary. In all experiments the same four-page Dutch reading passage was used (on the role of advertisement agencies). In experiments I, III, and V, the targets were 12 Dutch low frequency verbs. Subjects in these experiments were adult intermediate learners of Dutch as a second language (65, 45, and 35 Ss respectively). In experiments II and IV, these Dutch verbs were replaced by twelve pseudo-verbs. Subjects in these two experiments were adult Dutch native speakers (98 and 52 Ss respectively). In the margin of the text various sorts of cues were given, orienting the readers in various ways to the meaning of the targets. The following orienting cues (experimental conditions) were compared: (1) Translation: Translation of the target into LI (Exp. I), (2) Synonym: Dutch synonym of the target (Exp. II-V), (3) Context: a sample sentence providing a concise and highly specific context for the target's meaning (Exp. I and II), (4) Multiple Choice: four (Exp. I-III) or two (Exp. IV-V) verbs to choose from, one verb being a correct synonym, the other verbs giving wrong meanings (distractors), and (5) Control: absence of cue (Exp. I-II). In all five experiments Ss read the text and answered six multiple-choice comprehension questions, each question pertaining to the meaning of one or two paragraphs. This reading-for-comprehension task was unexpectedly followed by some posttests, eliciting knowledge of the twelve targets (incidental learning). In experiments IV and V half of the Ss were informed that retention tests were to follow the reading task (intentional learning).
The results of these five experiments and the conclusions drawn from them can be summarized as follows:
1. The retention of word meanings in a truly incidental task is very poor indeed. The chance that readers will remember the meaning of an unknown word, occurring once in the text, is minimal.
2. The presence of an orienting cue enhances word meaning retention, as compared to the absence of an orienting cue. In the latter case, readers often spontaneously infer a wrong (although possible) meaning.
3. From 2 it follows that in language pedagogy one should try to assess the differential effect of various orienting cues, rather than compare giving the meaning to the reader/learner (cue presence) with having the reader/learner infer the meaning without any help (cue absence).
4. A comparison between the Multiple Choice and the Synonym conditions showed in three out of four experiments that the former had a higher retention effect than the latter in an incidental (as opposed to intentional) learning setting. With the multiple-choice procedure, however, there is a chance that the readerAearner infers a wrong meaning (distractor). This procedure should therefore only be used in the classroom, with immediate feedback from the teacher. For unguided reading/learning at home, the synonym (or translation) procedure seems to be more appropriate.
5. The results of these experiments provide modest evidence for a mental effort hypothesis. The net retention effect (i.e. in an incidental learning task) of conditions in which the meaning of unknown words must be inferred by the reader/earner is higher than of conditions in which the meaning is given. However, as said under 4, it is assumed that language teachers will generally opt for the safer procedure of giving the meaning of an unknown word, rather than for the (somewhat) more effective procedure of having the reader/learner infer the meaning.
Correlation versus prediction in children's word learning: Cross-linguistic evidence and simulations