Class participation:

Although it is difficult to transcend subjective factors in evaluating class participation, there are several explicit criteria.  They include preparedness and the subsequent ability to make valuable contributions to the course.  In turn, valuable contributions are, among others, volunteering relevant information, asking questions whose answers benefit the group at large, the ability to provide intelligent answers to the teacher's and peers' questions,  the ability to engage in productive group and pair work, the ability to provide useful feedback to peers (for example, on writing assignments), and the contribution of relevant personal experiences and observations. The teacher might also opt to use announced or pop quizzes to check whether or how well you read a text or prepared grammar explanations at home and count these quiz grades toward class participation.

Finally, please note that coming to class in itself is not considered evidence of good "class participation", rather it is a prerequisite!