Elementary Statistics and Computer Application

Secondary data

• The data which are compiled from the records of others is called secondary data.
• The data collected by an individual or his agents is primary data for him and secondary data for all others. The secondary data are less expensive but it may not give all the necessary information.
• Secondary data can be compiled either from published sources or from unpublished sources.
 
Sources of published data:

1. Official publications of the central, state and local governments.
2. Reports of committees and commissions.
3. Publications brought about by research workers and educational associations.
4. Trade and technical journals.
5. Report and publications of trade associations, chambers of commerce, bank etc.
6. Official publications of foreign governments or international bodies like U.N.O, UNESCO etc.

Sources of unpublished data:

• All statistical data are not published. For example, village level officials maintain records regarding area under crop, crop production etc. They collect details for administrative purposes. Similarly details collected by private organizations regarding persons, profit, sales etc become secondary data and are used in certain surveys.

Characteristics of secondary data:

• The secondary data should posses the following characteristics. They should be reliable, adequate, suitable, accurate, complete and consistent.

Variables

• Variability is a common characteristic in biological Sciences. A quantitative or qualitative characteristic that varies from observation to observation in the same group is called a variable.

Quantitative data

• The basis of classification is according to differences in quantity. In case of quantitative variables the observations are made in terms of kgs, Lt, cm etc. Example weight of seeds, height of plants.

Qualitative data

• When the observations are made with respect to quality is called qualitative data. Eg: Crop varieties, Shape of seeds, soil type.The qualitative variables are termed as attributes.