Interactive Journals are to be used as a reference tool, much like your Anchor Charts are used as reference tools. The following image should explain the organizational set up of the journal. Just click on it.
For information and examples see below:
http://www.misd.org/users/0024/MISD%20docs/Interactive%20Math%20Journals.pdf
http://www.teachersworkroom.org/Math_Journals.html
http://funin4b.blogspot.com/2012/09/interactive-math-journals.html
http://www.youtube.com/watch?v=zzEiwsO7rtw
http://www.pinterest.com/dlr123/math-notebook/