When students engage in high cognitive demand science tasks they are invited into sensemaking and develop their own identities and capacities as doers of science. High cognitive demand tasks support students in making meaning of their actions rather than simply following rote directions. But how can we create or modify tasks to support this type of learning in the science classroom-where students are at the center of constructing and working with science ideas that are the target of your instruction. In this professional development course, teachers will learn how high cognitive-demand tasks increase opportunities for students to access learning. Teachers will explore ways of modifying tasks to increase students' abilities to engage in sensemaking. Facilitated by teachers with experience in designing and implementing high cognitive demand tasks, this course will assist teachers in gaining the knowledge and confidence needed to design and modify tasks for their science classrooms.