The purpose of this study is to identify and assess the difficulties experienced by the 11th grade students regarding generating, interpreting and comparing scatter plots. The study was carried out with 40 students-enrolled in 11th grade. The difficulties of students were identified through an achievement test on generating, interpreting, and comparing aspects. In the light of the test, the students identified as having difficulty were interviewed. It was found that the students experienced a range of difficulties related to generating, interpreting, and comparing aspects, and cannot be considered knowledgeable about scatter plots. Arguably, these difficulties can help explain the students' failures regarding scatter plots in the literature and provide a basis for the efforts to cope with these difficulties. In order to enhance the students' understanding of the concept, examples covering various aspects of the plots should be employed in instructional settings.