An investigation of the construct validity of the Test of Basic Process Skills in Science: A multitrait-multimethod analysis

Science process skills are described as a set of broadly transferable abilities, appropriate to all of the science disciplines and reflective of the true behavior of scientists. While science process skills have gained wide acceptance as an integral part of science curricula over the past 25 years, the development of valid and reliable instruments to assess those skills has lagged behind. Presently, few instruments exist which measure science process skills, particularly the basic process skills. Of the existing tests, few are adequately validated. Therefore, the purpose of this study was to gather evidence of the construct validity of the Test of Basic Process Skills in Science (BAPS), the only existing test of all of the basic science process skills for elementary and middle school students.;A multitrait-multimethod construct validation technique was used to gather evidence of the convergent and discriminant validity of the BAPS test. The technique requires the administration of at least two instruments with different test formats to measure the trait of interest, and at least two instruments, again with different formats, to measure a different or discriminant trait. The BAPS paper and pencil test and the BAPS performance test were used to measure the trait of interest, basic science process skills. The Test of Logical Thinking (TOLT) and the Bending Rods (RODS) Piagetian manipulative task were used to measure the discriminant trait, science reasoning ability.;The four instruments were administered to a sample of 151 seventh grade students from a west Florida school district. The scores were then correlated and presented in a multitrait-multimethod matrix. Convergent validity was established by correlating the BAPS paper and pencil and the BAPS performance. The resulting correlation was.80 (p ;The results show strong support for the convergent and discriminant validity of the BAPS. Considerable evidence of the construct validity of the BAPS can be inferred from this study.