Assessment is most useful, to both teachers and students, when it takes place during the teaching and learning process and is diagnostic in nature.
Assessment should be used to identify student thinking and strategies for working with fractions, rather than simply noting the answers that were correct or incorrect. Therefore the main focus should be on finding out what students can do, as a basis for further learning.
It is also helpful to detect misunderstandings and inappropriate strategies, so these can be targeted through explicit instruction.
Feedback to students on the strategies they use and how their understanding is progressing helps them to take responsibility for their own learning. This has been shown to enhance student motivation and engagement.
When teachers design the assessments themselves they are better able to gather the specific information needed at that time for their own students.
The Australian Association of Mathematics Teachers (AAMT) provides a more detailed discussion of good practice in assessment in their Position Paper on the Practice of Assessing Mathematics Learning, available on the AAMT website.
Different approaches to assessment will reveal different aspects of mathematical knowledge and skills. Using a variety of approaches is preferable to using only one.
Designing assessment tasks
A range of design aspects should be considered to assure the quality of assessment tasks. Teacher-designed assessment tasks have the advantage of being specific to the needs of the class.