This chapter introduces the conceptualization of data quality and presents a condensation of several approaches to data quality, demonstrating the application of the approaches in relation to Internet-generated data. Data quality concepts are examined through examples of commercial considerations on data quality, focusing on the consequences of poor data quality. This intuitive approach is followed by an example of a scientific empirical approach and, thirdly, of a systems view that treats data quality as theory-based or ontological. Lastly, a parallel between the data quality concepts of accuracy and precision is presented in relation to the methodological concepts of validity and reliability. Based on the concept of ‘fitness for use’, a further dimension, ‘documentality’, is introduced. By applying the concepts to a categorization of types of Internet data it is demonstrated how improvement of data quality can be reached though the use of Internet-generated data. With the advent of the Internet the term ‘to collect data’, has become more appropriate, as much data is already there to be collected without being generated. Many existing sources are open for investigation, while for other types of data the Internet is an efficient medium of data collection. The chapter is based upon a positive methodological criterion of data being validated, used, and plentiful.