What are Rubrics?  According to Wikipedia:

A rubric is a scoring tool for subjective assessments. It is a set of criteria and standards linked to learning objectives that is used to assess a student’s performance on papers, projects, essays, and other assignments. Rubrics allow for standardised evaluation according to specified criteria, making grading simpler and more transparent.

The rubric is an attempt to delineate consistent assessment criteria. It allows teachers and students alike to assess criteria which are complex and subjective and also provide ground for self-evaluation, reflection and peer review.

It is aimed at accurate and fair assessment, fostering understanding and indicating the way to proceed with subsequent learning/teaching. This integration of performance and feedback is called “ongoing assessment.”

Increasingly, instructors who rely on rubrics to evaluate student performance tend to share the rubric with students at the time the assignment is made. Pamela Flash states that “When students are apprised of grading criteria cozaar going generic from the start, they can be more involved in the process of working toward success.”[1] In addition to helping students understand how the assignment relates to course content, a shared-rubric can increase student authority in classroom, through transparency. Furthermore, rubrics reduce the amount of time teachers spend grading student work.

Below is a video that shows how Moodle 2.0 applies rubrics in its Workshop module.  Apparently rubrics will be added in more modules in upcoming releases.

This article explains in detail more concepts about how a teacher can grade “by rubrics” in Moodle:
http://www2.oakland.edu/elis/traindocs/Moodle/Workshop/index.html