Quantitative and qualitative assessments of data quality within the European Web Survey on Drugs

Overall, the paper provides insight into bigger the sample (and thus, the higher the response rate), the the validity of the EWSD, while also underscoring more probable it is that the data accurately estimates the true the importance of data quality assessments in population parameters in representative surveys (Dillman and future web survey data collection on drug use and Bowker, 2001). [...] The impact of the item format was examined for questions on The paper begins with an overview of the quantitative and frequency of use in the last year and assessed by comparing the qualitative methods used to assess data quality in the EWSD. [...] within a broader project that aimed to assess the validity and reliability of the Czech version of the questionnaire used in the first round of the EWSD (see the box ‘Assessing reliability and validity in the EWSD’). [...] The quantity of cannabis or resin for the questions on amount of purchased herbal cannabis and used in a pipe or joint depends on the shape of the pipe, the resin was too small for some of the participants. [...] The question on the number of days of use in the past and related slang, which makes it impossible to capture the 12 months allowed for such irregularity in drug use described complexity of methamphetamine markets in the one-size-fits- by the respondents.