Science Process Skills (SPSs) are fundamental skills to mastering science. To nurture students' SPS, inquiry based learning and student-center activities may work effectively. This study aims at analyzing: How Inquiry-based Learning and Student Team Achievement Division (INSTAD) affects science process skills compared with inquiry-based learning, Student Teams Achievement Divisions (STAD), and conventional learning method. The participants were 136 grade 7 students from 27 public middle schools in Surakarta, Indonesia. They were divided into 68 students with higher academic (HA) achievement and 68 students with lower academic (LA) achievement. A nonequivalent control group design with pretest and posttest were applied to get data on SPSs using a sort of essay test. The result indicates that: (1) While the outcomes of INSTAD and inquiry-based learning are comparable, they are significantly different compared with the outcomes of STAD and conventional learning. (2) Students in HA group have higher SPS than students in LA groups. (3) INSTAD, on an equal level with inquiry-based learning, significantly increases the students’ SPSs. Compared with other three methods, INSTAD was confirmed the most effective in closing the science process skills gaps between students in HA group and LA group. Keywords: inquiry-based learning, INSTAD, STAD, science process skills.

The students' biology learning results may vary among student, caused by several variables affecting the students' learning results, such as, learning style, critical thinking, metacognitive skills, learning models and some others. Many researches have investigated the correlation between critical thinking and students' learning results. However, a research investigating the correlation between critical thinking and learning results in Group Investigation (GI) learning has not been conducted. This research aims at investigating the correlation between the critical thinking and the learning results of senior high school students in Biology learning implementing the Group Investigation (GI) learning in Malang. This research was conducted in 2015 from July until December, using correlational design. The population of this research was all senior high school students in Malang. The subjects of this research were 32 students of class X MIA 2, and 33 students of class X MIA 4 of St Mary senior high school Malang. Data were analyzed using simple linear regression analysis. The results of this research showed that there was a correlation between students' critical thinking and their learning results with the regression equation of the correlation between the two variables Y = 0.988X + 0.095, having a reliability value of 73.9%.