THE EFFECT OF INPUT SPACING ON EFL LEARNERS' VOCABULARY KNOWLEDGE

The lag or the intersession interval (ISI) is the gap between two learning sessions. Lag effects are one of those effects that few studies have examined. Moreover, albeit a huge bulk of research on input spacing (i.e., phenomenon of distributed learning conditions) has been done in laboratory setting, few studies have directly examined this issue within real contexts. Therefore, the purpose of this study was to examine the impact of not only spaced-short but also spaced-long condition on the vocabulary knowledge of EFL learners. To achieve this goal, 37 intermediate level EFL learners were selected from four intact classes. The whole process took place in nine weeks; two testing sessions for pretest and a 28-day delayed posttest, two learning sessions and a final review session. Learning was done in two sessions. In this process, 20 target items were divided into 10 target words from each two lists. The first 10 words were studied during the first session, and reviewed during the review session. Eight days (intersession interval) ISI was specified for the spaced-long condition. Finally, a 1-day ISI was specified for the spaced-short condition. To do so, the second 10 words during the second session were studied, and then they were reviewed during the review session. The results of paired samples t-test revealed that spaced-long input was more effective than the space-short. Spaced-long condition could help learners for conceptual understanding to develop, reduce forgetting and provide opportunities for learners to learn more efficiently.

Duration and Exposure to Virtual Environments: Sickness Curves During and Across Sessions

Although simulator sickness is known to increase with protracted exposure and to diminish with repeated sessions, limited systematic research has been performed in these areas. This study reviewed the few studies with sufficient information available to determine the effect that exposure duration and repeated exposure have on motion sickness. This evaluation confirmed that longer exposures produce more symptoms and that total sickness subsides over repeated exposures. Additional evaluation was performed to investigate the precise form of this relationship and to determine whether the same form was generalizable across varied simulator environments. The results indicated that exposure duration and repeated exposures are significantly linearly related to sickness outcomes (duration being positively related and repetition negatively related to total sickness). This was true over diverse systems and large subject pools. This result verified the generalizability of the relationships among sickness, exposure duration, and repeated exposures. Additional research is indicated to determine the optimal length of a single exposure and the optimal intersession interval to facilitate adaptation.

The Effects of Physostigmine during the Acquisition of Avoidance Behaviour as a Function of the Intersession Interval

Rats were trained and tested on an avoidance task in a shuttle box. The change in the performance of the control rats over two sessions was found to be a U-shaped function of the interval between the sessions. The change in performance of rats injected with physostigmine prior to the second session was also found to be a U-shaped function of the intersession interval, although the drug was shown to impair avoidance behaviour. These results are consistent with those of Hamburg (1967) and of Biederman (1970), and support the general contention that cholinergic mechanisms in the brain are involved in the control of avoidance and escape behaviour in the rat. They do not, however, necessarily support the hypothesis advanced by Deutsch (1969, 1971) to describe a biochemical basis of learning and memory, especially if it is used to explain the effects of cholinesterase inhibitors on avoidance behaviour in the shuttlebox.