Panel single source refers to a research method in which data is collected from a select group of individuals or organizations, known as a panel, over a period of time. This approach allows for the tracking of changes and trends within the panel, providing valuable insights into consumer behavior, market dynamics, and other relevant factors. Unlike traditional surveys, panel single source data is gathered from the same group of participants, ensuring consistency and accuracy in the results. This method is commonly used in market research, media measurement, and other fields where longitudinal data is crucial for understanding and predicting trends.