3. What will You Accept as an Empirical Truth? Having specified the research questions, it is worth considering what to accept as valid answers. Different people make different assumptions about scientific truth. Take, for example, Jane’s causal question “Do fisheye-views cause an improvement in efficiency for file navigation?” Jane’s PhD advisor insists that the only trustworthy evidence to answer this question comes from experiments conducted under controlled laboratory conditions, pointing out that the only conclusive way to prove that A causes Bis to manipulate A in a controlled setting, and measure the effect on B. However, another member of Jane’s thesis committee is an experienced software practitioner and he claims that laboratory experiments are useless, as they ignore the messy complexity of real software projects. He points out that judgments about improvements to file navigation are subjective, and contextual factors such as distractions have a major impact. He suggests that Jane should conduct her research in the field, investigating what developers actually do on real projects The different advice Jane receives reflects major differences in opinion over the nature of truth, and how we arrive at it through scientific investigation. The conflicting advice arises from the different philosophical stances adopted by members of Jane’s committee. To understand the different stances, it helps to know that philosophers make a distinction between epistemology (the nature of human knowledge, and how we obtain it) and ontology (the nature of the world irrespective of our attempts to understand it. This separation helps us discuss what we accept as scientific knowledge separately from debates about the content of that knowledge Chalmers, Plato originally defined knowledge as justified true belief. In other words, to know something, you must believeit to be true, and have a clear justification for believing it to be true. However, epistemologists have argued for centuries about what form that justification should take. Empiricists argue that all knowledge is derived from our experiences and observations of the world, while rationalists argue that some part of our knowledge is innate, hence not derived from experience. Constructivists argue that we cannot separate knowledge from the language we use to express it – because the meanings of words are constructed by social convention, so is our knowledge. In this chapter we characterize four dominant philosophical stances (Creswell, 2002). The stance you adopt affects which methods you believe lead to acceptable evidence in response to your research questions. Being explicit about your stance also helps when talking and writing about research. You might not be able to convince other people to change their stance, but you will be able to argue cogently for why you chose the methods you did.