The method of data collection (survey, interview, experiment, etc.) used and the characteristics of respondents (such as, individual or group, young or old, male or female, rural or urban, etc.) also influence the nature and quality of data. It is possible that when you interview a student, s/he may report behaving in a particular manner in a given situation. But when you go for actual observation you may find just the opposite of what s/he had reported. Another important feature of data is that it does not in itself speak about reality.
Inferences have to be made from data. A researcher attaches meaning to the data by placing it in its proper context. In psychology, different types of data or information are collected. Some of these types are : i) Demographic Information : This information generally includes personal information like name, age, gender, birth order, number of siblings, education, occupation, marital status, number of children, locality of residence, caste, religion, parental education, occupation, and family income, etc.
ii) Physical Information : This category includes information about ecological conditions (hilly/desert/forest), mode of economy, housing conditions, size of rooms, facilities available at home, in the neighbourhood, in the school, mode of transportation, etc. iii) Physiological Data : In some studies physical, physiological and psychological data are collected about height, weight, heart rate, level of fatigue, Galvanic Skin Resistance (GSR), electrical activity of the brain measured by Electro-encephalograph (EEG), blood oxygen levels, reaction time, duration of sleep, blood pressure, pattern of dream, amount of salivation, running and jumping rates (in case of animal studies), etc., are collected. iv) Psychological Information : Psychological information collected, may relate to such areas as intelligence, personality, interest, values, creativity, emotions, motivation, psychological disorders, illusions, delusions, hallucinations, perceptual judgment, thought processes, consciousness, subjective experiences, etc. The above information could be from the point of view of measurement somewhat crude.
Like, in the form of categories (such as high/ low, yes/no), ranks which provide ordinal data, viz. first, second, third, fourth, etc., or scores ( , , , , , etc.) on scales. We also obtain verbal reports, observation records,