In every research study, it is undeniable that designing an effective questionnaire is the most important step. To illustrate, if the researchers design unclear or ambiguous questionnaires, he or she will finally end up with the useless data. This will surely result in the ineffective future usage of the data. Moreover, some types of data analysis methods require specific type of data. For example, correlation data analysis usually requires continuous variables. In order to come up with data in a specific form, it is important to ask the right type of questions. As designing an effective yet efficient questionnaire is quite complicated and time consuming, to facilitate the researchers who are looking for professional service on questionnaire design, we, Data Investigator offer you the service on designing a questionnaire, which is designed especially according to your specific topics and requirements. We also offer reliability analysis and IOC analysis.