The proposed study will be comprised of at least four sessions in the Spivack Center (Rm. X-140) on separate days (not counting recruitment, screening, or consent activities), each lasting approximately 1-2 hours. Subjects will commence a 1-week testing period during which they will wear the 3 actigraphy devices in their normal schedule and daily environment. On Days 2, 3, 4, and 5, subjects will use the eON-OFF motor diary application to select their current Parkinson state (e.g. "on", "off"). ON and OFF states are subjective measures identified by subjects, and are commonly used words in Parkinson's Disease treatment and research to describe symptom states. Symptom severity is directly linked to medication effectiveness. "On" is when the medication is working and symptoms are not severe or troublesome. "Off" is when medication has worn off, and symptom severity increases. Subjects will also use the eON-OFF motor diary application to verbally record symptomology every 30 minutes while awake. Subjects will complete paper VA Patient Motor Diaries to record ON and OFF states on Day 2, Day 3, and Day 4. Subjects will then complete the outlined set of activities during Phase I in a second phase to take place approximately one month later. All questionnaires, training and interviews will be administered one-on-one by a trained research assistant. All UPDRS' will be administered by a clinician. Ideally, subjects will be administered the study activities on the days listed above, but they are allowed a flexibility of +/- 4 days for scheduling appointments.