<![CDATA[This aim of research are to improve (1) the student learning activities at VIII G of 8 Junior High School at Surakarta academic year 2011/2012 on subject matter Pressure. (2) the student cognitive aspect at VIII G of 8 Junior High School at Surakarta academic year 2011/2012 on subject matter Pressure.This research used a Classroom Action Research with Kurt Lewin and Collaborative model that was held in two cycles. The cycles were started by preparation phase and then were continued execution phase that consist of action planning, action, observation, evaluation, and reflection. The research subject was VIII G of 8 Junior High School Surakarta student at academic year of 2011/2012, which was consist of 30 students in the subject matter Pressure. The techniques of collecting data were observation, interview with teacher, test, questionnaire and documentation. Techniques of data analysis were qualitative and quantitative.Based on result this research, it can be concluded that: (1) The application of CTL (Contextual Teaching and Learning) with model cooperative type NHT (Numbered Heads Together) can improve the student learning activities on subject matter Pressure in VIII G of 8 Junior High School in Surakarta academic year 2011/2012. It can be seen from the implementation of before cycle, cycle I and cycle II. Based on the indicators of activities can be concluded that: (a) student ask to teacher if there are uncleared explanation 6.66% at before cycle, 19.38% at cycle I, and 38.33% at cycle II, (b) student answer the teacher question independently 8.33% at before cycle, 34.51% at cycle I, and 46.66% at cycle II, (c) student give a perception for a friend opinion 1.66% at before cycle, 48.33% at cycle I, and 56.67% at cycle II, (d) student give an idea to solve the problem in group discussion 8.33% at before cycle, 60.00% at cycle I and 80.00 at cycle II, (e) student give the attention on the board or powerpoint slide during presentation of their teacher 72.33% at before cycle, 73.99% at cycle I and 96.66% at cycle II (f) student read physics book, module or student worksheet 35.11% at before cycle, 49.56% at cycle I, and 61.66% at cycle II, (g) student write the result of the problem in the discussion 20% at before cycle, 48.79% at cycle I and 88.33% at cycle II, (h) student write the object matter which has explained by teacher 65.01% at before cycle, 70.63% at cycle I and 90.00% at cycle II. (2) The application of CTL (Contextual Teaching and Learning) with model cooperative type NHT (Numbered Heads Together) can improve cognitive aspect on subject matter Pressure in VIII G of 8 Junior High School in Surakarta academic year 2011/2012. Based on 70 point as standard of minimum completion, the completed learning students were 66,67% at cycle I and 86,67% at cycle II.Key words: CTL, Cooperative Model NHT, Student Activities, Cognitive Abilities.]]>
