Set aside journaling time. Create a consistent block of time that your pupils can dedicate to journaling. If possible, make this block of time the same time every day. By being consistent, you can make it easier for students to become accustomed to the task of journaling and help them start to see journaling as an important part of their daily class routine.
Model journaling for students. Before you ask students to journal, show them what it looks like. Begin by presenting an inquiry-based prompt to your students, such as "Why is it not very bright out outside?" Using an overhead or LCD projector, work through this prompt, writing a journal entry in the same way your students might. For example, you could type your journal on your computer, including potential reasons for lack of brightness, like "There are lots of clouds" or "It is going to rain later."
Compose open-ended queries based on the unit topic to pose to students. Don't write journal questions that can be answered with a simple yes or no, but instead use only questions that students must elaborate on. Whenever possible, make these questions directly relevant to your current subject of study, showing students that their journals are a continuation of their in-class studying.
Allow students to compose responses on any topic they wish from time to time. By giving students "Free Journal Days" or days on which they can write about whatever they wish, you allow them the opportunity to express themselves or explore topics of particular interest to them in their journals.
Create a journal review plan. Decide how you will grade these student journals, and share this plan with your students. You may tell them that you are simply going to grade them for completion, and not judge their work as right or wrong, to encourage them to just try their hardest. Or you might decide to grade some entries for correctness. Whichever option you select, you must share your decision with your students to ensure that you allow them the opportunity to meet your expectation.
Allow time to discuss journal contents with pupils individually. Plan conferences with students at which you can discuss what they have been writing in their journals. By taking time to talk to your students about their journal contents, you make it clear to them that what they write is important to you and, therefore, worth their effort.