However, it can be done!
Students might come into your classroom with expectations of how you are going to act and what they will be expected to do. However, just because they harbor these beliefs does not mean that you have to conform to the mediocracy that has become much of teaching.
How do you do this you ask? By setting up an academic environment from the first day and ALWAYS keeping high expectations. What this means is that you as a teacher have to make a committed effort to be consistent, fair, and firm.
Consistency means that you come into class on the first day of school and assume that learning begins that day. You let students know right away that they might play in other classrooms but not yours. And then you follow through! You do not come to class unprepared (you wouldn't expect your students to!) You instead come with a lesson that begins at the beginning of class and ends at the end. (Believe it or not, this seems foreign to some students and teachers). Further, you act the same every day. You might not feel the best or you might be having a bad day because of something going on at home or at work, but you do not change your demeanor or, more importantly, they way you handle discipline problems. If you are not consistent, you will lose all credibility with students and the atmosphere you are trying to create will quickly disintegrate.
Fairness goes hand in hand with consistency. Do not treat kids differently. Sure, you will have personal likes and dislikes for different students, however, never let this bleed into your classroom. If you are unfair, you will quickly lose students who will not trust you. And trust is paramount for an effective academic classroom.
What this means is that you need to help the students understand that what you say is what you mean. And you must also help the students see that you believe in their abilities. Tell the students you know that they can learn what you are teaching, show them by your rapt attention, and then reinforce this by praising authentic achievements.
Which brings up the point: do you really believe that your students can learn? Many teachers have become cynical over time, believing that their students just can't do it or that their lives get in the way. Hogwash! We are wired so that we can learn! With that said, obviously students need to have completed the prerequisites for a course. You can't teach calculus to someone who has just finished Consumer Math. My point here, however, is that you need to examine your attitudes because they bleed through into class. Try not to say phrases like," This is just too advanced," or "We just won't spend the time trying to learn this." While these might sound innocuous, instead they are just off putting.
Finally, this brings up to the term firm. Discipline in your classroom should never be about raised voices and confrontations. It should be about consistent application of established rules. Further, learning will occur in a safe environment if the teacher establishes from the beginning that they will be fair but firm.
We are representatives of our discipline. It is our responsibility to commit ourselves to teaching an academic course of study. It is a sad state that students are surprised when teachers come in and actually expect their students to learn - not just to regurgitate the facts that they read in a text. However, if we fail to create an academic environment, we leave students with the implicit knowledge that school and therefore learning is not that important or it is for the 'brains' of the school and not them.