I went to a science notebooking class at NSTA and the teacher presenting exclusively had students journaling in their notebook. It was very impressive but I was completely overwhelmed by the amount of grading it represented and time involved on both the student and teachers part. It got me thinking though about adding a mini journaling component to the notebook.
I decided to try it and had students every Monday open their books to the first two blank page spread. They drew a line on each side dividing each page into twos and marked the top of the first page "Monday", at the bottom "Tuesday", at the top of the next page "Wednesday" and the the last section "Thursday." I would then give them a journal prompt of the day, which varied from draw and label all the parts of a flower to explain the process of photosynthesis in complete sentences.
This worked as a settling exercise as well as got them thinking about science when they walked through the door. I was strict about timing them. Students done early could look through their notebook and color any areas that needed coloring, write their homework in their agenda, etc.
To differentiate for lower students I didn't require full sentences (bullet points were fine) and/or we answered the question together as a group and recorded the response together.
I have not tried journal writing with my elementary students for no other reason then I simply do not have time. I have approximately 40 minutes - give or take - and I find I don't have enough time as it is to get through the lesson and activity of the day. I may try it during our end of year testing review and see how it goes.
I definitely liked mixing the type of journal entries around, i.e. draw and label, bullet points, full sentences, make a list, define three vocabulary words introduced this week, etc.
I use to give them a stand alone grade for their journaling and then a separate grade for their notebook assignments for the week. That was a bit time consuming and I ended up combining the two grades for their weekly (or my case bi-weekly) notebook grade.