State whether the following statements are True or False.
There are many sources of data.
True - There are many sources of data such as Census of India and National Sample Survey which collect, process and tabulate data on economic and social issues.
Telephone survey is the most suitable method of collecting data, when the population is literate and spread over a large area.
False - Telephone survey is suitable when the population is literate and spread over a large area, but mailing questionnaires would be more appropriate in such cases as respondents can answer at their convenience.
Data collected by investigator is called the secondary data.
False - Data collected by the investigator is called primary data as it is based on first hand information. Secondary data is collected by someone else.
There is a certain bias involved in the non-random selection of samples.
True - In non-random selection of samples, every individual does not get an equal chance of being selected, which leads to bias in selection.
Non-sampling errors can be minimised by taking large samples.
False - Non-sampling errors arise from data acquisition problems, non-response or bias in selection. These errors are not related to sample size and cannot be minimised by taking large samples. Only sampling errors can be reduced by increasing sample size.
Explanation
This question tests understanding of data collection methods and types of errors in sampling. The key concepts from the chapter include: (1) Primary data is first-hand information collected by the investigator; (2) Random sampling gives equal chance to all individuals, avoiding bias; (3) Sampling errors relate to sample size, while non-sampling errors relate to data acquisition, non-response, and selection bias; (4) Multiple agencies like Census of India and NSSO serve as data sources.