Web experiments and questionnaires are vital epidemiologic techniques that provide important information about public health and disease. They are a standard method of collecting data, which is typically less expensive and time-consuming than face-toface interviews, paper questionnaires mailed or automated telephone menu systems. Questionnaires and Web experiments are not without their limitations, which need to be addressed to obtain valid and reliable results.
A questionnaire may be affected by response bias. This is the tendency for respondents to answer questions based upon their opinions rather than the research objectives. Moreover, questionnaire design can influence responses in various ways. For example the wording of the question can affect the way respondents interpret and understand the question in the same way (reliable) and also, determine the subject matter you’re interested in (valid) or can answer with accuracy (credible).
A lack of enthusiasm or engagement with the questions can cause respondents to be less likely to give honest responses. In addition, a advantages and disadvantages of questionnaires lack of incentives or compensation can discourage respondents from taking the time to fill out a questionnaire.
Online questionnaires also pose challenges for some experimental designs, like positioning or reaction-time studies. The variation in settings for browsers as well as screen sizes and operating systems makes it challenging to measure and control the same variables across participants.
Finally, web-based surveys may only be accessed by people who are keyboard and Internet literate. This excludes a significant part of the population. In addition, it is often hard to Web researchers to inform participants after the experiment’s time-out.
