Many pet owners report sharing a bed with their pets, but little is known about the effects of pet-human co-sleeping, particularly in children. The overarching goal of this thesis was to increase knowledge of the measurement and effects of co-sleeping with pets. The objective of the first study was to compare sleep dimensions between children who co-slept with pets and those who did not. Children and adolescents completed questionnaires about sleep habits, kept a daily sleep log, and wore actigraphs for two weeks. Pet co-sleeping groups had similar sleep profiles and there were no differences between groups on subjective or objective sleep. The objective of the second proof-of-concept study was to consider methodological challenges in dyadic sleep research by testing novel assessment methods. A small convenience sample of dog-human dyads was recruited to wear accelerometers and proximity sensors. Participants completed a series of pet attachment questionnaires. Proximity sensors produced poor quality data and did not adequately measure distance between pets and humans. Dyadic accelerometry appears feasible and yields comparable data for humans and dogs.