When introducing yourself to a new class of students it is very important to identify the objectives for the course and use this first meeting to lay down a set of ground rules.
Ground rules set the boundaries within which the students must work; they enable everyone to have an equal opportunity to carry out their study whilst in the classroom.
An ideal way to discuss this is to split the class into two groups and come up with a set of rules. This enables a neutral ground for discussion and not a comparison between your list and theirs. As well as this, involving two teams can generate some competitive impetus, thus generating a larger list and a feeling of teamwork and achievement.
When reviewing the lists you have to have a fair and balanced view to all points indentified. Your objective is to do much more than lay down a few rules. In negotiating with the students you give them a sense of worth, this helps you gain their trust. You will have to shape these rules to ensure that they respond to the policies of the organisation you represent.
Any rules agreed upon within the group are more likely to be adhered to by the students, if broken, peer pressure will hopefully prevail and the student in question will respond. This is much more constructive than having their Teacher point the finger of authority, which may then lead to a negative response.