The document discusses various types and purposes of assessment in education. It defines assessment of learning, assessment as learning, and assessment for learning. Assessment of learning involves checking student progress against standards, while assessment as learning involves students reflecting on their learning through self-assessment. Assessment for learning focuses on identifying gaps between a student's current knowledge and the learning goal. The document also discusses principles of effective assessment, the roles school librarians can play in assessment, and examples of authentic assessment including observations, products, and conversations.