<![CDATA[Heavy-equipment hydraulics requires vocational students to connect pressure-flow relationships, component functions, circuit behavior, and technical reasoning. This study examined the integration of the TechDiscovery Inquiry Cycle, hereafter TDIC, which links technology discovery, inquiry formulation, experimentation, evidence interpretation, reflection, and application. A quasi-experimental pretest-posttest comparison-group design involved 70 Grade XI students at SMKN 1 Singosari, Indonesia. One intact class received TDIC and one received the school’s comparison instruction, with 35 students in each class. Cognitive achievement was measured before and after instruction. Because most score distributions departed from normality, the primary analyses used Wilcoxon signed-rank and Mann-Whitney U tests. The TDIC mean increased from 55.00 to 91.29; 34 of 35 students improved and none declined. Posttest ranks were also significantly higher for TDIC than for comparison instruction, with both inferential tests yielding p values below .001. Score dispersion decreased by 64.5 percent under TDIC compared with 31.7 percent in the comparison group, while the TDIC posttest minimum rose to 85. These findings indicate that TDIC was associated with higher cognitive attainment and a narrower distribution of achievement, a pattern described here as achievement convergence. Intact-class allocation, the single-school setting, and possible ceiling effects limit causal and generalizable conclusions.]]>
