The Internet has recently proved to be a very large place where social phenomena can be surveyed and an environment where powerful data collection tool can be used.
However, research reports have paid little attention to the errors affecting different techniques used within web-based surveys.
This paper discusses such issue by considering both sampling and non-sampling errors.
To reach this aim, the first part presents a preliminary review on the most popular web-based data collection techniques, so as to identify the nature and the features of the errors affecting each technique.
The second part focuses on a particular web-based technique – the observational grid – and discusses the advantages and the limits of its uses within web-based surveys.
The third part compares the performances of the observational grid in opposition to a similar tool – the evaluation grid – within the context of a research on tourist destinations websites quality. In particular, the expected advantages deriving from the use of the “less subjective” tool (the observational grid) are tested with specific reference to the production and the control of sampling and non-sampling errors.