Date of Award


Degree Type


Degree Name

Bachelor of Education (Hons.)


School of Education


Western Australian College of Advanced Education

First Advisor

Mr Mark Hackling


This research investigation was conducted to identify the difficulties encountered by secondary science students in the design of a controlled experiment. These difficulties were illuminated by studying the combination of knowledge, skills and strategies employed by experts. Three categories of individuals were used in the study, Year 10 science students, Year 12 science students and science lecturers who had completed doctoral studies in their fields. There were six subjects interviewed in each category. Each of the subjects were given a task which involved thinking aloud while planning a controlled experiment. When the subjects had completed the task, they were asked several questions to probe their understanding of the various concepts involved in experimental design. Each interview was tape recorded, transcribed and analyzed. The investigation revealed that the students generally had a poor understanding of many of the process skills used in planning experiments. In particular, the students experienced difficulty in hypothesizing, and in the identification and the control of variables.