In science and philosophy, an ad hoc hypothesis is a hypothesis added to a theory in order to save it from being falsified. Often, ad hoc hypothesizing is employed to compensate for anomalies not anticipated by the theory in its unmodified form... Scientists are often skeptical of theories that rely on frequent, unsupported adjustments to sustain them. This is because, if a theorist so chooses, there is no limit to the number of ad hoc hypotheses that they could add. Thus the theory becomes more and more complex, but is never falsified. This is often at a cost to the theory’s predictive power, however. Ad hoc hypotheses are often characteristic of pseudoscientific subjects.