The purpose of the present study was to investigate the effects of collaboration in encoding on individual performance of recall tests. In encoding, individuals and pairs worked on orienting tasks in incidental learning. The orienting tasks were of two types（story production tasks and word association tasks）. Communication was necessary to accomplish both types of tasks. However, negotiation was only necessary for the story production task.

  48 undergraduates were assigned 1 of 4 conditions: solo trial for story production task, solo trial for word association task, trials for story production task in pairs, and trials for word association task in pairs. All participants were required to remember the words presented in solving the task in each condition.

  Analysis of the data showed that performances on the recall test were facilitated significantly by working on the orienting tasks in pairs. Performances were also facilitated in the story production task. However, the effect on the task was not statistically significant. These findings suggest that the elaboration of words to be remembered is facilitated by communication in the negotiation used for accomplishing the orienting tasks.

  This paper tries to provide significant discussion on present circumstance of cooperative learning in senior high school. Emphasis is placed here on possibility of cooperative learning as an effective approach for improving teaching and enhancing learning of high school students.

  Three case studies from various pattern of high school are presented for describing problems and possibility of applying cooperative learning in practice.

  From this discussion it can be seen that applying cooperative learning in high school supports teachers, 1) to pay more attention to each student needs and abilities; 2) to learn more about them as adolescent particularly in the new age; and 3) to develop methods of cooperative learning and design of teaching contents effectively in practice.