Assessment is an important part of the learning process, and your assessment criteria should align well with your goals for student learning and with the classroom activities that you build out of those goals.
You will likely require students to complete different sorts of assignments over the course of a semester. It's important that these assignments require students to practice and demonstrate the skills and understandings defined in your learning goals. Most of us think of student assignments as the basis for the grades that students will receive in the course. While such assignments are often formally evaluated and contribute to a final grade, they should also be activities that allow students to practice what they are learning and what they have learned.
Techniques for assessing students include both formative and summative techniques. The distinction between formative and summative assessment is crucial, but it's better to think of the two sorts of assessment as being on a continuum rather than as being fully distinct from one another. Briefly stated, formative assessment is intended to help the student learn, and summative assessment is a measure of what the student has learned.
Try to assess early and often. Students learn much better from their engagement with course material if they're encouraged to engage publicly and then get feedback from others about their engagement. As noted in the description of formative assessment, this feedback might be informal and relatively unstructured. Note that formative assessment doesn't have to come only from you as an instructor. It can also come from other students in the class through peer review. If provided adequate structure and support, students can provide very useful feedback to each other and even to themselves. In fact, this is crucial if faculty are not to be overwhelmed by the task of assessment. Peer feedback and peer instruction can be highly rewarding and engaging activities for students, giving them a sense of accountability and efficacy. There are advantages to helping students learn to self-assess that go beyond relieving faculty burden. In particular, students who learn to monitor their own learning gain much more than content-knowledge from a course—the ability to self-assess is a crucial requirement for lifelong learning.
Another way of looking at this is to consider the ?stakes? involved in student learning assessment. Traditional assignments like essays, tests, and quizzes are typically considered high-stakes grading. This simply means that they comprise a major component of a student's grade, and hence are likely to motivate students to maximize their performance. But high-stakes grading assignments risk revealing student misunderstandings and confusion too late (and at great cost to the student). Low-stakes grading, on the other hand, helps instructors discover misunderstandings or confusion before high-stakes assignments are given. One such method using low-stakes feedback, for example, is Just-in-Time-Teaching (JiTT), which asks students to answer a few questions the day before the class period so that the teacher can review the responses (are the students getting it?) and adjust her material and approach accordingly.
It can be very informative to know something about what students are learning even before they write a paper or an examination. Learning this can give you a richer understanding of how students' preconceptions and misconceptions are informing their work with the material provided in class readings, discussions, and lectures. Classroom Assessment Techniques, often referred to as CATs, can help you do this. To offer just a couple of examples here, at the beginning of a class or unit you might consider having students respond to questions that elicit their background knowledge about the material to be studied. Another very popular CAT is to ask students to take a minute or two at the end of a class session to write out a question about the assigned reading or the lecture that they believe to be both important and unanswered. A quick read through these questions after class gives you an indication of the depth of students' understanding and also of some points that you might want to address in subsequent classes.
The learning goals you have defined for your students should shape both the overall design of your course and the specific student assignments. The learning goals should also inform your grading criteria and practices. Many faculty find it helpful to develop an explicit grading rubric. Such a rubric lays out the criteria an instructor will use when evaluating student work. Developing a rubric before grading an assignment can take time, but using it as you grade will help you maintain consistency and fairness in your grading.