BOBs are Building Outside the Blocks Projects that come in two different forms: One-Off and Tri. When coupled with the BOB Approach (read about the BOB approach in here), this twist on project- based learning (pbl) helps students build skill, autonomy, connection and community. Regardless of the presentation cycle, a teacher can employ several One-Off BOBs over a school year or a few One-Offs and a Tri-BOB.