It is important to use respondents own ideas and words in the determination of what defines their attitudes, rather than to simply ask them to rate what the experimenter considers important in attitude formation. Semi-structured interviewing, used in conjunction with Generalised Procrustes analysis has been used experimentally to understand the underlying psychological constructs which determine risk perceptions 10 associated with genetic engineering, both relative to other technological hazards, and between different types of genetic engineering application. When different technologies are compared, all food related technologies are perceived negative relative to other technologies. What differentiates genetic engineering from, for example, nuclear power, is the extent to which it is regarded as unknown. The negative perceptions associated with nuclear technology are well defined.
Genetic engineering is an unknown quantity as far as public perceptions are concerned.
Similar techniques have been used to determine what is critical in determining risk perceptions associated with genetic engineering. Negative perceptions are associated as much with ethical concern and questions relating to perceived need for the technology, as perceptions of risk associated with its application. However, increasing the specificity of hazard stimuli has been found to alter the factor structure of underlying risk perceptions. Public recognition of the tangible benefits of the technology appears to mediate risk perceptions, but only in the case of concrete applications. Control did not emerge as an important determinant of risk perceptions.