One type of student portfolio contains work that shows the student's progression through the course of the school year. For example, writing samples might be taken from the beginning, middle, and end of the school year. This can help show growth and provide teachers, students, and parents with evidence of how the student has progressed.
A second type of portfolio involves the student and/or teacher selecting examples of their best work. This type of portfolio can be graded in one of two ways. In many cases, these items are graded normally and then placed in the student's portfolio. This portfolio can then be used as evidence of student work for college and scholarship applications among other things. The other way that these types of portfolios can be graded is to wait until the end of a term. In this instance, typically the teacher has published a rubric and students collect their own work for inclusion. Then the teacher grades this work based on the rubric.