What is common across all kinds of assessments? For what purposes might tests be better suited as an assessment tool? When would you choose to use these different kinds of assessments and why?

Command Performance: Creating Accountability That Works | Edutopia

While schools wait for innovation in accountability testing, some are taking matters into their own hands, creating performance assessments that guide and strengthen teaching and learning. Typically, these assessments come in the form of portfolios and presentations — tasks that bear something in common with the kind of work students may ultimately do in college or in a job.