Strategy in which students manage their learning by mapping out what they Know, Want to know, and Learned. KWL charts help students access prior knowledge and help teachers assess where students are in their learning.
KWHL: Know, Want to find out, How to learn more, and Learned is a variation on the KWL chart, as elaborated by The Graphic Organizer. STW is another variation used for viewing illustrations: What do I See? What do I Think? and What do I Wonder?
For further explanation:
NCREL elaborates on KWL charts and provides a KWL template.