Conducting surveys in transportation research is becoming more complex. Depending on the survey subject, the survey format and the circumstances of the sample collection the motivation of respondents to participate and consequently the results can vary substantially. Skewness of samples and sample selection bias occur to different degrees. This study compares different surveys which were created to capture the acceptance regarding shared autonomous minibuses in Germany. By analyzing distributions of behavior, perception and intention to use the services, biases in the datasets are worked out. The results show that voluntary on-site surveys lead to more positive perception of minibuses
