(i) There are many sources of data. – False
There are only two sources of data- primary and secondary data sources. The collection of data from its original source is termed as primary source of data. On the other hand, the collection of data that has already been collected by somebody else in the past is termed as secondary source of data.
(ii) Telephone survey is the most suitable method of collecting data when the population is literate and spread over a large area. – False
In a Telephone Survey, the investigator asks question over the phone or mobile. So, there is no need for the person to read the survey form. Hence, this method of collecting information is the most suitable for the illiterate population spread over a large area. Moreover, this method is less time consuming as the investigator need not to visit each person individually from door to door.
(iii) Data collected by an investigator is called the secondary data. – False
The data collected by an investigator is called the primary data, whereas, the data that is already in existence being collected by any other investigator is known as secondary data.
(iv) There is a certain bias involved in the non-random selection of samples. – True
Non-random selection of items obstructs the equal chance of every item of the Universe of getting selected. Hence, there may be a high probability of involvement of personal biasness of the investigator in the non-random sample selected.
(v) Non-sampling errors can be minimised by taking large samples. – False
The errors that are related to the collection of data are termed as Non-sampling Errors. If the field of investigation or the population size is large, then the possibility of Non-sampling Errors also increases. So, Non-sampling Errors maximises by taking large samples.