Context-based and science-technology-society (STS) approaches to teaching science in high school have become widely used over the past two decades. They aspire to foster more positive attitudes to science while, at the same time, provide a sound basis of scientific understanding for further study. This paper reviews the detailed research evidence from 17 experimental studies undertaken in eight different countries on the effects of context-based and STS approaches, drawing on the findings of two systematic reviews of the research literature. The review findings indicate that context-based/STS approaches result in improvement in attitudes to science and that the understanding of scientific ideas developed is comparable to that of conventional approaches. The approaches also result in more positive attitudes to science in both girls and boys and reduce the gender differences in attitudes. The paper also considers issues emerging from work in the area in relation to study design and the constraints which may militate against the use of experimental research designs when gathering evidence of impact of interventions. A fundamental constraint is the extent to which it is possible to make comparisons between existing methods and interventions when the aims are overlapping but also differ in significant ways.