Pitfalls of Quantitative Surveys Online

is growing very quickly. Indeed, it reduces costs while allowing exploration of relatively large
files and enables effective use of a  variety of research tools. The academic research is more
reserved towards developing online surveys. Demands on the quality of data are the main
cause; Internet surveys do not meet them and thus do not allow drawing objective conclusion
about the populations surveyed.
Unqualified use of the Internet may significantly influence data and information obtained from
their analysis. The problematic definition of the population that is under investigation may
result in a fault of its coverage. Its existence can be shown, for example, on a confrontation of
the total and Internet population of the Czech Republic, the total and Internet population of the
Czech households, etc. Representation of the population through an online panel may cause
bias, depending on how the panel is created. A relatively new source of error in an online survey
is the existence of “professional” respondents.
The sampling method from a population or an online panel can lead to the emergence of such
a sample that is not representative and does not allow inference to the population at all, or only
in a very limited way. Even probability sampling, however, can be problematic if it is affected
by a higher rate of non-responses. The aim of this paper is to summarise the possible sources of
bias associated with any sample survey, but also to draw attention to those that are relatively
new and are associated with the implementation of just quantitative surveys online.