Web-based experiments and questionnaires are a crucial method of epidemiology which provides vital data on the state of public health and diseases. They are a standard method of gathering data that is usually less expensive and time-consuming than face to-face interviews, mailed paper questionnaires or automated menus for phones systems. Questionnaires and Web experiments do not come free of limitations, which need to be addressed to achieve 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 and not on research goals. The layout of a survey can influence responses in a variety of ways. For example the wording of the question could affect whether respondents understand the question and interpret it in the same way (reliable), whether the question measures the subject you are interested in (valid), and whether they can accurately answer (credible).
A lack of enthusiasm or engagement with the questions could also make respondents less likely to give honest answers. A lack of incentives or compensation could also deter respondents from filling out the questionnaire.
Online questionnaires also pose challenges for some experimental designs, for example, positioning or reaction time studies. It is challenging to control and measure the same variables across people due to the different settings for browsers operating systems, browser settings, and sizes of screens.
Finaly, Web-based surveys can only be accessed by people who have keyboards and Internet literate. This excludes a substantial segment of the population. In addition, it’s generally difficult for Web researchers to explain the results of their research when the window for an experiment has closed.