This exit ticket was created as a means for students to be able to reflect on what they learned, whether you are asking them to discuss a current lesson or previously learned material. The goal, however, is for them to write their exit ticket in the form of a tweet they would post to Twitter using 140 characters or less. (Note: ***The title includes "@Science" to give students someone to respond to, but you can have students use a different Twitter handle.)
Personally, I have found that this activity works well as a simple and fast formative assessment to gauge students' level of understanding of content, concepts, and ideas.
Please note: The document was designed to generate two forms on one page so that you can easily cut the page in half to help save paper.