"Questionnaires...are by far the most important measurement instrument statisticians use to grasp the phenomena to be measured. Errors due to an insufficient questionnaire can hardly be compensated at later stages of the data collection process. Therefore, having systematic questionnaire design and testing procedures in place is vital for data quality, particularly for measurement error." (Brancatt, G. et al, 2006).
A questionnaire is a formalized set of questions for obtaining information from respondents. The overriding objective is to translate the researcher’s information needs into a set of specific questions that respondents are willing and able to answer.
I am in full support of Brancatt, G. et al, 2006 that; "Questionnaires are by far the most important measurement instrument statisticians use to grasp the phenomena to be measured.” A questionnaire is the main means of collecting quantitative primary data. A questionnaire enables quantitative data to be collected in a standardized way so that the data are internally consistent and coherent for analysis. Imagine how difficult it would be to analyze the data of a national survey conducted by 40 different interviewers if the questions had not been asked in a standard way, that is, if the interviewers had asked different questions using different wording and order. A questionnaire ensures standardization and comparability of the data across interviewers, increases speed and accuracy of recording, and facilitates data processing. The qualities of questionnaires have proven their importance; they are Practical, Large amounts of information can be collected from a large number of people in a short period of time and in a relatively cost effective way, they can be carried out by the researcher or by any number of people with limited affect to its validity and reliability, the results of the questionnaires can usually be quickly and easily quantified by either a researcher or through the use of a software...