This study, conducted at Northeast Catholic High School for Boys in Philadelphia, was designed to determine if a significant difference existed between ninth-grade students experienced in Introductory Physical Science and ninth-grade students experienced in conventional General Science in ability to manipulate basic physics laboratory equipment, construct and graph tables of data, and interpret physics data. A total of 78 ninth-grade students experienced in Introductory Physical Science (the experimental group) and a comparable group of 78 ninth-grade students experienced in conventional General Science (the control group) completed the following: a physics pre- and posttest consisting of appropriate questions from the Tests of the Physical Science Study Committee (PSSC); the Welch Science Process Inventory; and three experiments from the PSSC curriculum. The findings showed that the ability of the students experienced in the Introductory Physical Science tended to be greater than the ability of the students experienced in conventional General Science in constructing and graphing tables of data and in interpreting physics data. There was no significant difference between the two groups in the time needed to complete the experiments or in ability to manipulate basic physics laboratory equipment. (Author/MLH)