Unconscious stage of learning in the acquisition of a second language: Experimental designs in long-term everyday learning situations

The present research was conducted in the context of the view that implicit memory may be involved in the process of learning general vocabulary. The present authors' research on implicit memory has showed that effects of repeated minimal studying are maintained for extended periods (e.g., Ueda & Terasawa, 2008). The prediction made in the present study was that effects of general learning would continue to accumulate over time. The participants in the learning experiment were 15 high school students. The stimulus materials were over 1,000 English words. In the experiment, which continued for 8 months, the students studied English vocabulary words that usually take a long time to acquire. A new methodology was used that controlled the learning and test schedule in detail for each word. The students continued to study at home using a computerized program that resembled vocabulary cards. Analysis of the very large amount of reaction data obtained illustrated how the effects of learning were accumulating at unconscious levels. This confirmed the effectiveness of the scheduling method used. The discussion deals with the possibility that vocabulary skills might not increase monotonically.