Why use a rubric?
Rubrics provide students with the expectations of a project and enable teachers to give an objective assessment of student performance. See the website CARL- Center for Advanced Research on Language Acquisition for a wonderful review of the rationale of rubrics.
RubiStar-a site to help teachers build quality rubrics; you can customize the rubrics to fit your project dimensions and required elements. Rubric starters are available on a variety of topics: oral projects, multimedia, math, writing, reading, art, science, music, and work skills. RubiStar requires you to set up a free account to use the site. Check out the rubric I created for a poster project for a unit on environmental issues.