Bill Martin Jr, an elementary-school principal, teacher, writer, and poet, held a doctoral degree in early childhood education. His many books, among them the bestselling classics Brown Bear, Brown Bear, What Do You See?; Polar Bear, Polar Bear, What Do You Hear?; Panda Bear, Panda Bear, What Do You See?; and Chicka Chicka Boom Boom, are a testament to his ability to speak directly to children.