National Research Council polices (NRC, 2012a, 2012b) and the Every Student Succeeds Act (ESSA) of 2015 (Pub. L. No. 114-145) call for educators to have active roles in teaching to achieve new goals and purposes for education. A high priority is teaching content knowledge and information fluency skills that will result in deep learning, higher order thinking, and college and career readiness. Information fluency involves abilities to find, evaluate and use print and digital information effectively, efficiently and ethically to create knowledge useful in solving real-world problems. This action research (Blaxter, Hughes, and Tight, 2010) investigates co-teaching in a college, undergraduate physical sciences course. Information and technology literacy skills (ACRL, 2016) were taught in the context of a 12-week unit about the design of control variable experiments. Co-teaching was done by a professor of physical sciences and a professor of library and information science. Assignment learning objectives provided a framework for analysis of 24 students' scores that tells a story of the process of co-teaching through articulation of two professors' engagement in instructional interactions, creation of materials and strategies to increase information fluency as well as descriptions of students' completion of assignments. It was concluded that co-teaching effectiveness involves intensity of effort in shared planning, organization, delivery and assessment of instruction; shared physical and/or virtual space of instruction; and in the combining two areas of academic expertise in delivery of cross-curricular instruction.