First, the YouthStyles survey was not administered to a nationally representative random sample of US youth. Instead, youth who were invited to complete the survey were randomly selected from only those households that participated in the HealthStyles survey administered months earlier. Furthermore, the response rate was 52%, so the results may not be representative of the US population of youth aged 12–17 years. However, as illustrated in table 1, the survey sample characteristics closely approximated characteristics of the 2010 US Census, providing some insight into the representativeness of the sample. Second, for the question about riding frequency, the response options of riding every 2 or 3 weeks were inadvertently excluded. Although the effect of this omission cannot be emphatically quantified, any effect is thought to be small because only seven respondents did not answer the question, and the five positive response options were collapsed into three categories for the analysis. Third, because of the study's small sample size, some of the response categories for the questions about riding frequency and helmet use were combined. By combining the response categories, we may have obscured important differences in riding exposure or frequency of helmet use. Fourth, because ATV riding and helmet use were self reported and the recall period was 12 months, the estimates presented may be subject to misreporting and recall bias. Fifth, the survey did not collect other important variables such as the size of ATV most often ridden, seating position driver or passenger or crash experience. Previous studies have reported that most young riders ride adult sized ATVs.