A questionnaire is normally used in primary data collection methods. It needs to be designed carefully so that we can make correct deductions from statistical analyses of the results. The main points in questionnaire design are:
1. A large company is considering a complete re-shaping of its pay structures for production workers. What data might be collected and analysed, other than technical details, to help the management to come to a decision? Consider both primary and secondary sources.
2. Suppose that a national survey has revealed that 40% of non-manual workers travel to work by public transport while one-half use their own transport. For all workers, 47.5% use public transport and one in every ten use methods other that their own transport. A statistical worker in a large factory (which is known to have about three times as many manual workers as non-manual workers) has been asked to sample 200 employees for their views on factory provided transport. He decides to take a quota sample at a factory gate B at five o’clock one evening.
(a) How many manual writers will there be in the sample?
(b) How many workers who travel to work by public transport will be interviewed?
(c) Calculate the quota to be interviewed in each of the six-sub groups defined.
(d) Point out the limitations of the sampling technique involved and suggest a better way of collecting the data.
3. The makers of a brand of cat food “Purrkins” wish to obtain information on the opinions of their customers and include a short questionnaire on the inside of the label as follows:
