Web-based research and questionnaires are vital epidemiologic techniques that provide crucial information about public health and disease. They are the most commonly used methods of collecting data, which are usually more affordable and efficient than face-toface interviews, mail-in questionnaires, or automated telephone menu systems. However questionnaires and Web experiments have a number of limitations that must be addressed to ensure that they are reliable and valid results.
A questionnaire may be affected by response bias. This is the tendency for respondents to answer questions based on their own opinions, rather than research objectives. Additionally, questionnaire design can influence responses in a variety of ways. For instance the wording of the question can affect whether respondents comprehend and interpret the question in the same way (reliable) or whether you can determine the topic you’re interested in (valid), or are able to answer the question accurately (credible).
Respondents might also experience survey fatigue or lack of interest in the questions which decreases the probability of them offering honest answers. In addition, the absence of incentive or compensation may dissuade respondents from taking the time to fill out the questionnaire.
Online questionnaires also pose a challenge for some experiments, like reaction-time or positioning studies. It is challenging to control and measure variables across participants due to the variations in browser settings operating systems, settings, and screen sizes.
The bottom line is that Web-based surveys can only be accessed by people who are keyboard and Internet knowledgeable. This excludes a large portion of the population. It’s also difficult for Web researchers to provide participants with a report after the experiment window has closed.