Abstract: The primary purpose of this study is to determine the effectiveness of using simulations as an instructional tool in an introductory doctoral level statistics course. The study focuses on the impacts of simulations on students’ attitudes and understanding of statistical concepts, as well as how the simulations could inspire students’ positive attitudes and improve statistics performance or would fail to help. In addition, since the statistics anxiety has been a primary obstacle to students’ statistics education, and “statistics anxiety” is experienced by as many as 80% of graduate students (Onwuegbuzie, 2004). The researcher is interested to explore the details of the statistics anxiety related attitudes of this group of students, including examining their anxiety levels before and after taking the introductory statistics course. If the anxiety levels were not the same, what factors led to the release or acceleration of the statistics anxiety related attitudes after students complete the introductory statistics course. Moreover, the course has a hybrid online or flipped structure, and the target population for this study is social sciences adult learners, with limited background in statistics or mathematics. Given the prevalence of the online course, especially considering the constraints and background of this target population, the researcher is interested to determine the preferred statistics learning style of the social sciences adult learners, whether in-class or online, as well as the factors leading to the particular preference. The mixed method research approach is used in this study, combing both quantitative and qualitative research methods. A total of twenty-two social sciences adult learners is involved in this study, five of which are from the Spring semester, while seventeen of the remaining are from the Fall semester. The quantitative method of Mann-Whitney U test and Kruskal Wallis test, together with the qualitative method of thematical analysis, produce some impressive findings. The use of simulations could inspire social sciences adult learners’ positive attitudes toward statistics, develop a high self-efficacy, and improve the understanding of the statistical concept of Central Limit Theorem (CLT), even though not significant. In addition, the social sciences adult students’ anxiety levels diminish after they complete the introductory statistics course. Moreover, the online learning style is presently inappropriate for the introductory statistics course for adult learners from social sciences.