The purpose of the study was to determine whether exposing junior high school students to a unit on design in construction technology and to a unit on design in manufacturing technology significantly affects their achievement on a test measuring "Technological Principles of Design" when compared to a group of junior high school students exposed only to a unit on design in construction technology. The data from four treatment groups in the Long Beach Unified School District in California were analyzed, and results indicated that there was a significant amount of additive knowledge when students had been exposed to two units in design, one in construction technology and one in manufacturing technology, as opposed to only one exposure of construction technology. Statistical analysis also indicated a significant difference between the achievement scores of the seventh grade control group and the seventh grade experimental group, with the latter group achieving at a higher level. The findings indicate that the technological concepts and principles of design are significantly additive when a second unit (in manfacturing) is provided to build upon the concepts provided by a prior design unit (in construction). This Ph.D. thesis was submitted to The Ohio State University. (GR)