When teachers shift to teaching 21st Century Skills in a more student-centric learning environment, they need to rethink the idea of assessment -- or testing to see if students are understanding what they are suppose to be learning. In fact, 21st Century Skills should replace the need for tests and examinations as we know them. The reason we have tested students in the past is to not only determine the extent to which students have understood a given subject to see if they should move on, but also to compare a student to their classmates to see where they might "rank" in their classroom.
The problem with this system is lag-time. The time it takes from when the student takes the assessment to when the grade is given. Days, if not weeks, have pasted and the students have all moved on regardless of the results of the assessment. What I like about project-based learning and 21st Century Skills is that most of this lag-time problem is eliminated. Using school technology in student assessment is one of the great keys to success in our future classrooms and schools.
Take for example; learning to add fractions in the fourth grade. When 21st Century Skills like creativity an innovation are added to the process, problems like lag-time are reduced. In this case students were taught the concept of adding fractions with a simple computer game using slices of pizza. A computer game which gave the students IMMEDIATE FEEDBACK, they knew instantly wether or not they understood the concept and the game would not let them move on until they had mastered the skill. After the initial concept was understood the students then had to create their own video game to teach about adding fractions using the Scratch programming language. So instead of just the vain repetition of adding fraction problems on a worksheet, students kept practicing the skill of adding fractions as they tested their video game, and as they tested each others (communication and collaboration).
So the point is that as we think of teaching 21st Century Skills to our students, we need to always be thinking about 21st Century assessment as well. The two are dove-tailed together.