Currently, she is examining college students' use of principle-based reasoning about the carbon cycle and how teaching strategies increase student reasoning abilities. She is also working with colleagues to develop K-12 learning progressions (descriptions of how students develop understanding of a certain topic over time) for environmental literacy. Dr. Hartley was trained as an ecologist and also conducts research related to disease ecology and the effects of disturbance on communities and ecosystems. Currently, she is examining the effects of prairie dog burrowing and grazing on the establishment of non-native plant species in urban areas.