Questionnaire design is a lengthy process that requires careful attention. A questionnaire is an effective evaluation tool and should not be taken casually. Like any other scientific experiment, it is properly planned and executed. Data should not be collected first and then searched for something interesting. The hypothesis is formed and an questions are worded such that they are helpful in proving or disproving the hypothesis.
A questionnaire is only as good as the questions it contains. There are many criteria that need to be met before the questionnaire is considered a perfect research tool. Careful review and testing is necessary to eliminate minor mistakes that can cause great changes in meaning and interpretation.
Questionnaires are usually made flexible, allowing the collection of both subjective and objective data through the use of open or closed format questions. Modern day softwares have made the collection and extraction of data more efficient.