*Data refers to information about a phenomenon (Something) For instance; Individual_Name, age, sex, tribe, weight, height, income, expenditure, religion
Statistical data is numerical in Nature.
Data collection is a premilinary stage in any statistical study. It must be undertaken with utmost care because correct data will lead to a valid conclusion of the study.
Data may be classified as follows:
- Source: Thus Primary and secondary data*Secondary data; data that is already existing in some form. It is used for a purpose other than that for which it was collected.*Primary data; is data collected for the first time by the investigator and used for the purpose for which it was intended
- Measurement: Qualitative and Quantitative data*Qualitative; measured categorically such as honesty, health and so on.*Quantitative data; measured numerically such as rate, income, Age and so on.
- Precision measurement: Used to classify Quantitative data.*Data measured approximately is known as continuous data such as weight, time, distance*Data that is measured precisely is known as Discrete data such as number of children in a family, number of cars in a parking lot
- Number of variables: A variable is any characteristic that changes in value when observed in different people, places or things*Data based on two variables is; Bivariate*Data based on more than two variables is; Multivariate*Data based on one variable is; Univariate