@article{UNY23188, title = {THE EFFECT OF MEDIA-ASSISTED GUIDED DISCOVERY METHOD OF CONCRETE OBJECTS TO MATHEMATICAL CRITICAL THINKING ABILITY}, author = {. Khairunnisa and Kamil Ghufron and . Kadir}, journal = {Proceeding of International Conference On Research, Implementation And Education Of Mathematics And Sciences 2015 (ICRIEMS 2015), Yogyakarta State University, 17-19 May 2015}, publisher = {Faculty of Mathematics and Sciences Yogyakarta State University}, year = {2015}, abstract = {The purpose of this study was to describe the effect of media-assisted guided discovery method of concrete objects on students? mathematical critical thinking. This research was conducted at SMP Darul Maarif in South Jakarta, Academic Year 2013/2014. The method used was a quasi-experimental with Control Group Post-test Only Design. The sample was 70 students which taken cluster randomly. Data of the research were collected through the test. Of the students? mathematical critical thinking ability. The hypothesis of the research was tested by using t-test. The results showed that the students? mathematical critical thinking abilities were taught by guided discovery learning methods aided concrete media objects is higher than students were taught by conventional teaching methods (of t = 2.40 and t-table = 2.00 ). It can be seen from the results percentage from each indicators whcih covers: For , the indicator which focussed on questions of the experimental class reached 78.7\%, while the controlled class reached 61.76\%. Argument analysis indicator of the experimental class reached 66.2\%, while the controlled class 47.55 \%. In answering the questions which being supported by argument of the experimental class reached 61.11\%,while 48.53\% in the control classes. For the indicators in making decisions and considering the results of the experimental class reached 76.59\%, while the controlled class 70.59\%. Based on the research results, it can be drawn conclusion that mathematical instruction on the subject matter of flat figures using media-assisted guided discovery method of concrete objects significantly affected on students' mathematical critical thinking ability. Key word: mathematical critical thinking, media-assisted, guided discovery}, url = {http://eprints.uny.ac.id/23188/} }