This research aimed to find out the effect of Logan Avenue Problem
Solving Heuristic (LAPSH) learning towardthe student's mathematical problem solving skill on the seventh grade of SMP Negeri 1 Ajibarang in academic year 2017/2018. The populations of this research were the seventh graders of SMP Negeri Ajibarang with class VII C as the experiment class and class VII B as the control class that were taken using cluster random sampling. The instrument of
this research was posttest whose results were obtained after the experiment class
implemented LAPSH learning and control class implemented direct learning. The
posttest results were processed using the support of IBM SPSS Statistic 21 software by doing independent sample t test. The results showed that the value of sig was 0.0195 which was less than (0.05), so it caused H0 to be rejected and Ha to be accepted. It could be concluded that the mathematical problem solving skill
of students who used LAPSH was better than the one who used direct learning.