Thesis (Bachelor of Secondary Education major in Mathematics) -- University of Rizal System-Morong.

EXECUTIVE SUMMARY: The study focused on the effectiveness of the instructional videos in teaching geometry for grade 7 students. It was conducted at URS-Laboratory Schools during the School Year 2014-2015, with thirty (30) students of Grade 7 from University of Rizal System Laboratory Schools it utilized an experimental method of research. The subject-respondents were grouped into two to compose the experimental and control groups with fifteen (15) students each. It also employed pretest and posttest design. It made use of the experimental method of research utilizing pretest/posttest design. The respondents were given pretest and posttest to determine the effectiveness of the developed instructional videos in Geometry for Grade 7. The lessons included two (2) selected topics in Geometry such as Parallel Lines and Transversals and sum of Angles of a Triangle. The average in the three grading periods was the equating variable in assigning the number of students in experimental and control groups. The control group was exposed to the traditional method of teaching Geometry while the experimental group was exposed to the developed instructional videos in Geometry. To determine the level of performance of the experimental and control groups as revealed by the pretest and posttest scores, mean and standard deviation were applied. To determine whether there is a significant difference on the level of performance of the experimental and control groups as revealed by the pretest and posttest scores with respect to the different lessons, dependent t-test was used and to determine if there is significant difference on the level of performance of the experimental and control groups as revealed by the posttest scores with respect to the different lessons, independent t-test was applied. Meanwhile to determine the level of effectiveness of the developed instructional videos in Geometry, mean percentage increase was utilized. The study found out that the control group without the instructional videos in Geometry for grade 7 was developing before the lesson and approaching proficiency and proficient after the lessons respectively. While the experimental group with the interpretations Approaching Proficiency before the lesson and with interpretations of Advance and Proficient in posttest; the study found out that there was significant difference on the level of performance of the experimental and control groups as revealed by the pretest and posttest of the experimental and control groups as revealed by the pretest and posttest scores with respect to the lessons Parallel Lines and Transversals and Sum of Angles of a triangle in Geometry, there was significant difference on the level of performance of the experimental and control groups as revealed by the posttest scores on lessons Parallel Lines and Transversals and Sum of Angles of a Triangle in Geometry, and also that instructional videos in teaching geometry for grade 7 students is effective in the lesson Parallel Lines and Transversals and moderately effective in the lesson Sum of Angles of a Triangle. Moreover, in the light of the finding, the study concluded that the instructional materials in technology like videos contributed to the performance of the students in Geometry. From the conclusions drawn, the study recommended that the developed instructional videos in Geometry may be utilized by teachers in the teaching of Geometry. Also, the developed instructional videos in Geometry may be subjected for validation for better improvement of the instructional material and parallel studies may be conducted considering other group of students and other variables such as academic performance in Mathematics.