This article examined response format effects on norm prevalence (i.e., the percent of individuals who could specify a norm). Data were collected in Dilek Peninsula Büyük Menderes Delta National Park, in Turkey. Respondents were randomly assigned to one of two conditions. In the “semi-open” response format, respondents (n = 458) “wrote a number” for an acceptable number of visitor encounters. In the “closed” format, respondents (n = 459) “circled a number” of acceptable encounters, along a range of possible responses. Results showed that encounter norm prevalence was significantly and consistently higher for the closed format of the survey, as compared to the semi-open version. In addition, among those reporting a norm, the average tolerance levels were statistically higher in the semi-open format. Implications for applying the normative approach across different cultures are discussed.