Web-based questionnaires and experiments are vital methods for analyzing epidemiology and provide important information about public health and diseases. They are a common method of gathering data, and are usually more affordable and efficient than face-to-face interviews, mailed questionnaires, or automated phone menu systems. However questionnaires and Web experiments are not without limitations that should be addressed to ensure reliable and valid results.
A questionnaire can be affected by response bias. This is the tendency of respondents to answer questions based upon their opinions, rather than research objectives. The layout of a survey can influence responses in a variety of ways. For example, the wording of the question could influence whether respondents are able to comprehend the question and interpret it in the same way (reliable) as well as whether the question is a good indicator of the topic you are looking for (valid), and the ability of respondents to accurately answer (credible).
Respondents might also look here experience survey fatigue or a lack of engagement with the questions being asked which reduces the chances of them providing honest answers. A lack of incentives or compensation may make it difficult for respondents to fill out the questionnaire.
Online questionnaires can also be challenging for certain experiment designs like studies of response time or positioning. The varying settings of browsers screens, sizes, and operating systems makes it difficult to measure and control the same variables for different people.
Finaly, Web-based surveys can only be accessed by people who are keyboard and Internet knowledgeable. This excludes a significant part of the population. It’s also difficult for Web researchers to update participants after the experiment window has ended.