Students in Mrs. Wilson's fourth-grade classroom watch in anticipation as the guest teacher, Ms. Davis, demonstrates binary signaling using a lightbulb that flashes when she holds it in her hands. She challenges them to guess what she is trying to "say" while making the lightbulb flash on and off, explaining that the lightbulb stands for "0" when it is off and "1" when it is on. The students quickly realize that she is saying "hi" to them with a simple combination of flashes. Meanwhile, 15 other teachers from the district sit along the perimeter of the classroom, watching Ms. Davis teach about creating and sending signals using binary code as a part of a "fishbowl" exercise in a professional development (PD) workshop. This article describes the PD program offered by The Center for Integrative Natural Science and Mathematics (CINSAM) at Northern Kentucky University through which teachers learn from watching master teachers teach "Next Generation Science Standards" (NGSS)--aligned lessons with real students.