Questionnaires and web trials allow experts to reach a far wider crowd than classic paper questionnaires, cellphone or face-to-face interviews and is conducted for a fraction of the cost. This will make them a favorite tool designed for market research and customer studies as well as subconscious studies. However , irrespective of their a large number of advantages offered with some disadvantages which can weaken the quality of the results.
One serious problem is that right now there is much less control over data capture than with a paper set of questions. With a Internet experiment the participant can view stimuli on their own personal device and could also adjust settings including screen size, browser, internet connection and in some cases the standard font. Consequently that each respondent activities a discreetly different questionnaire and this can impact how they get suggestions.
Another problem is set of questions taking exhaustion which can lead to respondents leaving the study. The way to steer clear of this is to make the questionnaire simply because short as it can be and only find out that are relevant to your research. You may also try to randomize the order of the read more questions and pretest the questionnaire before performing it to ensure that the questions are clear and understandable.
Finally, you have to keep in mind that Web experiments derive from voluntary engagement so they can be susceptible to motivational confounding than laboratory experiments. To counter this, you can use a web marketplace such as SONA devices (often used for undergraduate diagnostic tests at universities), MTurk or Legendary to generate participants.