This chapter details the practical, theoretical, and philosophical aspects of experimental science. It discusses how one chooses a project, performs experiments, interprets the resulting data, makes inferences, and develops and tests theories. It then asks the question, "are our theories accurate representations of the natural world, that is, do they reflect reality?" Surprisingly, this is not an easy question to answer. Scientists assume so, but are they warranted in this assumption? Realists say "yes," but anti-realists argue that realism is simply a mental representation of the world as we perceive it, that is, metaphysical in nature. Regardless of one's sense of reality, the fact remains that science has been and continues to be of tremendous practical value. It would have to be a miracle if our knowledge and manipulation of the nature were not real. Even if they were, how do we know they are true in an absolute sense, not just relative to our own experience? This is a thorny philosophical question, the answer to which depends on the context in which it is asked. The take-home message for the practicing scientist is "never assume your results are true."

In this chapter we set out to consider what is needed to ensure that Africa’s infrastructure remains financially sustainable throughout its life cycle. Managing the operational phase is at least, if not more, crucial than ensuring a project is constructed in the first place, but evaluation, particularly in relation to affordability, is weak even at the global level. We identify that in Africa there are frequently weak systems of governance, fragile and risky political institutions and lack of financial management capacity. We empirically examine five Ghanaian projects in electricity generation, water desalination, and the use of private finance to deliver and operate university buildings, to demonstrate financial and accountability shortcomings. We identify four methods that could improve financial sustainability for African infrastructure projects: namely, the establishment of independent infrastructure agencies; training and salary support of competent government technical staff; a move to more transparent decision-making; and the introduction of project monitoring and contingency planning.