What: Short, simple questionnaire for students at the beginning of a course or new unit/topic. Designed to assess students' pre-conceptions.
Assessment can take many forms on a continuum from formative (informal) to summative (formal). Informal assessment is usually quick and easy, done during class to assess student understanding on the fly. Formal assessment is more complex and takes time -- both for the instructor to create and the student to complete -- and is best used for assessing student understanding at the completion of a course or large unit of learning. See the diagram below (courtesy of Sara Lowe) for an illustration: 
What: Provide students with a few problem and ask them to state the principle(s) that best applies to each problem in order to solve it. Designed to assess and is most useful in courses requiring problem-solving.
What: Instructor asks students to paraphrase part of a lesson for a specific audience and purpose, using their own words. Designed to assess students' understanding of information and their ability to transform it into a form that can be meaningful to specific audiences.
What: SEE-I stands for Statement, Elaborate, Example, Illustration. In this exercise, students are asked to state a concept in their own words. Here is a template to follow:
S: Statement: _____ means ______.
E: Elaborate: In other words, ______________.
E: Example: An example of ____ would be _____.
I: Illustration: Draw something, find a photo, make a diagram, or create a picture-in-words using a metaphor or analogy: It's like __________.
What: At the end of class, the instructor asks the students to answer the question "What was the most important thing you learned during this class?" Designed to assess how students are gaining knowledge, or not.
What: Prepare a handout with a matrix of three columns and several rows. At the top of the first two columns, list two distinct concepts that have potentially confusing similarities (e.g. hurricanes vs. tornados). In the third column, list the important characteristics of both concepts in no particular order. Give your students the handout and have them use the matrix to identify which characteristics belong to each of the two concepts. Designed to assess whether or not students understand the distinction between two or three categories of information that has been presented.
What: Requires students to write a one- or two-page analysis of a specific problem or issue.The person for whom the memo is being written is usually identified as an employer, client, etc. who needs the student's analysis to inform decision making. Designed to assess students' ability to analyze assigned problems by using the discipline-specific approaches they are learning, as well as to assess students' skill at communicating their in a clear and concise manner.
What: The instructor asks the students to answer the question "What was the muddiest (most unclear) point in [the lecture, assignment, homework, etc.]?" Designed to assess where students are having problems.
What: After introducing a principle or theory to students, pass out index cards and ask students to write down one possible, real-world application of what they just learned. Designed to assess whether students understand the applications of what they learned.
What: Requires students to write down a quick list of pros and cons on a particular topic. Designed to assess students' skills in analysis and critical thinking.
What: Think-pair-share is a collaborative learning strategy in which students work together to solve a problem or answer a question. First, students think individually about a topic or answer to a question; then, they share ideas with one classmate in a pair. Discussing an answer with a partner serves to maximize participation, focus attention and engage students in comprehending the reading material. At the end of the exercise, each pair may share their conclusions with the rest of the class.