Is a "fair test" the only way to carry out science investigations? Many children (and primary teachers) following the National Curriculum in England and Wales would answer "yes" to this question. This is because fair test investigations have historically been promoted in national assessment, published curricula, schemes of work and assessment criteria. But can a "fair test" help a child find out what is living in the pond in the school wildlife area? Fair testing is a very effective way to answer certain types of scientific question, often in the form of an investigation. Too often children and primary teachers equate science enquiry or "doing an investigation" with "doing a fair test." In this article, the author and her colleagues outline the project they have completed about how children answer scientific questions about the world around them. The project, "It's Not Fair," focuses on good practice in science inquiry. It aims to redress the balance of science enquiry activities in the classrooms by recognising that fair testing is only one of several ways of learning through science enquiry. (Contains 2 figures and 3 boxes.)