This study provides an initial statistical approach as an alternative model to detect the fraudulent practice estimation of national examination (NE). Trends, patterns, and relationships were analysed from the national examination (NE) scores and the national examination integrity index (NEII) on pre-and post-computer-based national examination (CBNE) of the 103,273 high school science students in Aceh Province. Looking at the trends and patterns of the pre-post CBNE implementation, descriptive statistics were used by comparing the average (Mean) of the NE, NEII, and the standard deviation of national examination (SDNE) in the group of regencies/cities. Picturing the relationship between the NE and NEII, linear regression and curve estimation was applied. The result shows that there are striking differences and gradual changes between the pre-post CBNE's implementation in each regency/city. In the span of three years (2015-2017), a downward trend showed in the NE's scores along with the implementation of CBNE which increased the NEII's value. In the pre-CBNE period (2015), a striking pattern emerged in the form of low NEII, high NE, and low SDNE which indicated the existence of fraudulent practice estimation of the national examination. [Paper presented at the Annual International Conference on Mathematics, Science, & Technology Education (AICMSTE) 2019.]