All scientists have discipline-specific scientific practices that allow them to study their subject. Recently, science educators have started teaching these practices as an integral part of developing students’ understanding of how science works. The Next Generation Science Standards (NGSS Lead States, 2013) heavily emphasize the teaching of both science content and discipline-specific practices. In the field of astronomy, little research has been done specifically addressing the teaching of Science Practices In Astronomy (SPIA). In this study, we build upon previous work identifying student ideas about SPIA. Our research group worked closely with a science teacher at a public alternative school to implement a curriculum deliberately designed to teach students SPIA. Students were interviewed both before and after instruction to determine if their ideas about SPIA had changed. Classroom instruction was also recorded to determine what may have caused these changes in student ideas. After instruction, student ideas about the astronomical practices of spectroscopy and taking multiple observations over time improved significantly in sophistication, while ideas about observing nearby objects, far objects, and photography did not improve significantly.