EN
With the widespread Internet access and increased importance of this medium in everyday life, the web also becomes more and more vital tool in conducting social and psychological research. The Internet research might be conducted by using many different metods: from interviews and focus groups, through questionnaires and experiments to data bases. The topis of research online might concern many different issues, nort necessarily related to the Internet itself. The article discusses possibilities related to conductiong Internet research by presenting various methods and advantages of online research. However, the main part shows and discusses the basic problems and challenges of using online research. The authors point to the issues which should be considered in order to ensure the quality of social science methodology and suggest how to handle different sources of errors. In the first place, problems related to the response rate will be presented, such as motivation to participate in the research, non-response errors, and dropouts. The next part of the article identifies problems related to the measurement error as a result of non-standarized situation, different skills of respondents nature od computer-madiated communication and technical obstacles. The final part presents ethical aspects of conducting research online and discussed situation of a respondent on the Internet and possibilities of using the Internet content.