Psychological data refers to the information collected by psychologists from different sources using diverse methods. This data relates to individuals' covert or overt behaviour, subjective experiences, and mental processes. Unlike other sciences, psychological data is distinct in nature as it deals with human behaviour and experiences.

Psychologists collect various types of data including demographic information (such as name, age, gender, education, occupation, family income) and physical information (such as ecological conditions, housing conditions, facilities available). These different types of information help in understanding behaviour comprehensively.

An important characteristic of psychological data is that data are not independent entities. They are located in a context and are tied to the method and theory that govern the process of data collection. Data are not independent of the physical or social context, the persons involved, and the time when behaviour occurs. For instance, we behave differently when alone than in a group, or at home and in office.

Data form an important input in psychological enquiry. They approximate the reality to some extent and provide an opportunity to verify or falsify our ideas, hunches, and notions.

However, psychological data has certain limitations such as lack of absolute zero point, relative nature of psychological tools, and subjective interpretation of qualitative data.