The Effect of Inquiry Learning Model and Group Investigation Learning Model on Students’ Cognitive Skill and Critical Thinking Skill in the Ecosystem Topic at SMA Bhayangkari 1 Medan

This study aimed to determine the effect of learning models on students: (1) cognitive skill and (2) critical thinking skill in the Ecosystem topic at SMA Bhayangkari 1 Medan. The method used is quasi experiment research with a sample of 3 classes randomly determined using cluster random sampling technique. X1 class was taught by Inquiry Learning model, X2 class was taught by Group Investigation Learning model, and X3 class was taught by Conventional model. The test instruments in this study were tests of cognitive abilities in the form of multiple choices, tests of critical thinking skills in the form of essay tests. The data analysis technique used ANACOVA with SPSS 21.0 for Windows program. The results of the study showed that there were influences of learning models on: (1) students cognitive skill (F = 5.14, P = 0.01) and (2) students critical thinking skill (F = 63.49, P = 0.00). The students cognitive skill who were taught with Inquiry Learning model (73.75 ± 13.60) were not significantly different from Group Investigation Learning model (77.21 ± 10.69) (P = 0.47) and not significantly different from those taught in Conventional model (67.71 ± 11.43) (P = 0.10). The students critical thinking skills were taught by the Inquiry Learning model (72.40 ± 8.77) differed significantly from those taught in Group Investigation Learning model (79.80 ± 7.01) (P = 0.00), and were not significantly different from those taught by Conventional model (68.76 ± 66.21) (P = 0.12). The follow-up of the results of this study was expected to teachers to be able to apply Inquiry learning model and Group Investigation learning model to Ecosystem topic in an effort to improve Cognitive Skill and Critical Thinking Skill of students at the schools.