I think the assessment task should match the content. Some types of content are just more naturally going to lend themselves to certain types of assessments, such as a lab or demonstration instead of a written test. If you want to test understanding of the scientific method, asking a student to do a science fair project is a better assessment than a multiple choice test.
As a teacher, I use a variety of assessment techniques that are influenced as much by the abilities and interests of my students as by where we are in the topic. For my students this year, I use quite a bit of "art" in my assessments. For example, we studied the types of science and science professions by first looking at student drawings of their concept of a "scientist." To make things a little more interesting, they presented their vocabulary of one chapter with drawings of any concept that lent itself to that approach. In lab, I use both lab reports and "practical" tests of understanding of lab techniques. I believe that a "hands on" approach works very well, especially for students who have difficulty expressing themselves in written asssessments. This is particularly important for my students who have recently transitioned from our English as second language program. I also use lab report grades as test grades to aid students who are not good at written tests.
I do use written assessments but this year I have added appropriate illustrations to my tests, with much success. Students tell me that this not only aids them in understanding what is being asked, but also helps them to hold their interest. I especially advocate this approach for the level at which I teach -- 9th grade and the subject I teach -- Physical Science which can be a little dry if not handled with creativity.
In sum, my choices of assessment techniques are influenced greatly by the ability and knowledge levels of my students while, at the same time, assessing all of the required concepts of my subject, science department, and state testing requirements.
If this entry were moved to the Science Discussion Forum, science teachers could provide specific examples of different types of assessment tasks they have used and explain what factors influenced the decision to use them.
In the teaching of any subject, criteria employed to select assessment tasks vary depending on the purpose of the assessment. Formative assessments are used during the learning process to measure the student's comprehension of knowledge and the student's application of new skills and to identify difficulties that students may be experiencing. Summative assessments are used at the completion of a unit or course of study to evaluate the comprehensive acquisition of information and utilization of that information. Summative assessments are usually the basis of assigned grades.