Self-report survey-based data collection is increasingly carried out using the Internet, as opposed to the traditional paper-and-pencil method. However, previous research on the equivalence of these methods has yielded inconsistent findings. This may be due to methodological and statistical issues present in much of the literature, such as nonequivalent samples in different conditions due to recruitment, participant self-selection to conditions, and data collection procedures, as well as incomplete or inappropriate statistical procedures for examining equivalence. We conducted 2 studies examining the equivalence of paper-and-pencil and Internet data collection that accounted for these issues. In both studies, we used measures of personality, social desirability, and computer self-efficacy, and, in Study 2, we used personal growth initiative to assess quantitative equivalence (i.e., mean equivalence), qualitative equivalence (i.e., internal consistency and intercorrelations), and auxiliary equivalence (i.e., response rates, missing data, completion time, and comfort completing questionnaires using paper-and-pencil and the Internet). Study 1 investigated the effects of completing surveys via paper-and-pencil or the Internet in both traditional (i.e., lab) and natural (i.e., take-home) settings. Results indicated equivalence across conditions, except for auxiliary equivalence aspects of missing data and completion time. Study 2 examined mailed paper-and-pencil and Internet surveys without contact between experimenter and participants. Results indicated equivalence between conditions, except for auxiliary equivalence aspects of response rate for providing an address and completion time. Overall, the findings show that paper-and-pencil and Internet data collection methods are generally equivalent, particularly for quantitative and qualitative equivalence, with nonequivalence only for some aspects of auxiliary equivalence.
