The assessment of internal behaviors such as thoughts, feelings, or physiological symptoms not seen by the naked eye are often assessed with indirect measures such as self-reports and questionnaires given the lack of accessibility and observations by outside observers. The self-management of human behaviors, including internal events, carries socially valid implications for an individual’s quality of life, including children and individuals with neurological, developmental, and intellectual disabilities. This study aimed to address the following question: are there valid measurement procedures (e.g., collecting data on physiological responses) to analyze the correspondence between self-reports of emotional states and observable and measurable overt behaviors? To address the limitations in measurement validity of private, covert behaviors, the primary researcher of this study conducted a correspondence check of these three measurements with two participants with autism spectrum disorder in the following manner: collected heart rate data of the participants via a wearable device (Fitbit® Charge 5), conducted direct observation and data recording of overt behaviors, and collected data on the participants’ self-report of their emotional or physiological state via a 5-point rating scale across several time periods per session. Results of the study showed a strong positive correlation between observer and participant ratings from the 5-point rating scales; however, physical activity of the participants seemed to consistently mask true heart rate readings of the emotional responses. More research can be done on the correspondence of these three variables and their implications for guiding self-management programs of private events