in practice. In theory, an optimal foraging model gives researchers specific, quantitative predictions about a predator's optimal decision rule based on the hypotheses about the currency and constraints of the system. However, in reality, it is difficult to define basic concepts like prey type, encounter rates, or even a patch as the forager perceives them. Thus, while the variables of OFT can seem consistent theoretically, in practice, they can be arbitrary and difficult to measure. Furthermore, although the premise of OFT is to maximize an organism's fitness, many studies show only correlations between observed and predicted foraging behavior and stop short of testing whether the animal's behavior actually increases its reproductive fitness. It is possible that in certain cases, there is no correlation between foraging returns and reproductive success at all. Without accounting for this possibility, many studies using the OFT remain incomplete and fail to address and test the main point of the theory. One of the most imperative critiques of OFT is that it may not be truly testable. This issue arises whenever there is a discrepancy between the model's predictions and the actual observations. It is difficult to tell whether the model is fundamentally wrong or whether a specific variable has been inaccurately identified or left out. Because it is possible to add endless plausible modifications to the model, the model of optimality may never be rejected. This creates the problem of researchers shaping their model to fit their observations, rather than rigorously testing their hypotheses about the animal's foraging behavior. Optimal Foraging Theory in Archaeology Optimal Foraging Theory has been used to predict animal behaviour when searching for food, but can also be used for humans (specifically hunter-gatherers). Food provides energy but costs energy to obtain. Foraging strategy must provide the most benefit for the lowest cost - it is a balance between nutritional value and energy required. The currency of Optimal Foraging Theory is energy because it is an essential component for organisms, but it is also the downfall of Optimal Foraging Theory in regard to Archaeology. Optimal Foraging Theory assumes that behaviour is to some extent influenced by genetic makeup. However this can be hard to accepted in relation to complex animals with a high behavioral flexibility. Human behaviour is not always predictable when using the premise of Optimal Foraging Theory - hunter-gatherers could for ritual or feasting purposes choose a game which would