<![CDATA[The rapid transformation of digital technology in the Industrial Revolution 4.0 era demands continuous pedagogical innovation within vocational high school (SMK) education. In instructional practice, learning in several vocational schools still heavily relies on conventional teacher-centered methods and static print media, which frequently leads to low student engagement, cognitive overload, and suboptimal academic achievement in technical subjects. This study aims to determine, analyze, and evaluate the empirical effect of implementing digital learning media based on Google Sites on the academic learning achievement of eleventh-grade students at SMK Negeri 8 Semarang. This research employed a quantitative methodology utilizing a pre-experimental pretest-posttest control group design. The population consisted of all eleventh-grade students majoring in Computer Network and Telecommunications Engineering (TJKT) in the 2025/2026 academic year (N=70). Using purposive sampling, 70 students were allocated into two homogeneous groups: class XI TJKT 1 as the experimental class (N=35) taught using interactive web-based Google Sites media and class XI TJKT 2 as the control class (N=35) taught using conventional direct instructional methods. The research instrument comprised a 20-item multiple-choice test on Computer Network Technology validated through Pearson Product-Moment correlation (r_count 0.344) and Cronbach's Alpha reliability analysis (alpha = 0.814), with all items exhibiting moderate difficulty index and good discriminatory power. The empirical findings demonstrated that the post-test mean score in the experimental class (84.29) was significantly superior to that in the control class (68.00). Furthermore, the average Normalized Gain (N-Gain Index) for the experimental class reached 0.671 (categorized as medium-to-high effectiveness), substantially outperforming the control class which obtained an N-Gain Index of 0.330. Inferential statistical analysis using the Independent Samples t-Test yielded t_count = 11.311 with a significance value of p 0.001 (df = 68), leading to the rejection of the null hypothesis (H0) and acceptance of the alternative hypothesis (Ha). It is concluded that digital learning media based on Google Sites significantly improves vocational student learning achievement by bridging abstract network engineering concepts into concrete interactive representations, fostering dual coding cognitive processing, and enabling self-regulated learning]]>
