The mode of data input will be decided on the basis of model of printed questionnaire. If the questionnaire consists of multiple choices, optical scanner is the best choice. The keyboard typing or uploading the scanned version of written paper is suitable for theoretical a paper which requires description about the topic.
Telephone Survey – Automated computer system to capture the details of survey is best option as it reduces the margin of human error related to typo, grammatical mistake etc if the instructions are clearly explained to participants. Otherwise, if it is abstruse paper which needs the presence of subject matter expert, human interaction is essential where responses can be recorded into the system.