 background for teachers this unit focuses mostly on the mechanics of creating posters but it is important to place all of this poster activity in a broader context the goal of this activity is to engage students in scientific discussion and argument for most students the word argument means a fight a disagreement it is really important  a learning objective to help them understand that scientific argument is something different there is an excellent discussion of this objective in ready set science  published by the national academies press in fact there is a whole chapter titled making thinking visible talk and argument you can read the chapter for free online by clicking here  one of the key ideas from this book is that you should begin by establishing the norms for scientific discussion in your classroom this is not just a matter of good classroom control it reflects what really happens in the profession of science there are rules of the road that scientists follow as they critique each other s work your class too should have clearly defined rules for its scientific discussion  ready set science s suggestions about establishing classroom norms is available online by clicking here  poster presentations can be done in a variety of settings 1 students can make presentations to other science classes once school arranged for students to present to middle school science classes in the same district 2 have a parents night where family and community members can come to the school to see the posters and hear the students make presentations 3 schedule a poster session at a school board or parentteacher organization meeting the creation of a poster involves a great deal of material that is normally covered in an english class think about the possibility of team teaching this unit with an english teacher possibly as a project that would receive both english and science credit the same is true for math  mercury in watersheds background for teachers presentation  