Abstract:
—This research is a quantitative research, which
aims to find a valid and reliable instrument for testing the
mathematical reasoning ability for junior high school students.
The process of analysis this instrument starting from (1) a
literature review, (2) the preparation of the instrument, (3) the
teoritical validity, that is testing the readability limited to five
students and test the validity by experts, (4) revision, (5) the
empirical validity, and (6 ) data analysis. Readability test is
applied to five students with the choosen materials. Expert’s
judgement conducted by two supervisors, three lecturers of
mathematics eduction, a junior high school math teacher, and a
bahasa lecturer. Empirical validity was done in 9th grade in one
of junior high schools in Bandung. The results obtained in the
form of mathematical reasoning ability test instruments are
valid, each coefficient validity item is more than 0.41 that mean
degree of validity was high and very high. The coefficient
reliability was 0.64 (more than 0.41) belonging to the high level of
reliability. Thus, mathematical reasoning ability test can be said
as valid and reliable so that it was classified as good instrument
