Prince & Smolensky (1993) describe a version of OT, one in which maximal harmony is achieved in small steps of gradual harmonic improvement, because a more restrained GEN is limited to making modest changes in the input one at a time.

In this chapter, I explore some of the differences between classic OT with free GEN on the one hand and persistent OT with restrained GEN on the other. We will see, as Prince and Smolensky (1993) suggest, that the single-operation and harmonic-improvement requirements do indeed have consequences that are different from those of the familiar OT model. This chapter's goal is not to decide squarely for one version of OT over the other, though elsewhere (McCarthy 2006) I argue in favor of a derivative of persistent OT called OT-CC (for OT with candidate chains).