Formative Assessments can be thought of as "practice" assessments that are on-going throughout the term.  They are used by the student and teacher to gauge what the student is learning.  This provides for instantaneous modifications to the teaching to enhance learning. 

Summative Assessments are the most common usage of evaluating the effectiveness of the program and are used at the end of a section, term, or year.  They are used to make judgments about the individual's competency or mastery level in that subject.

EXAMPLES

Formative Assessments	Summative Assessments
Quizzes	Final Exams
Portfolios	Standardized Exams
Work samples	National Credentialing Exams