On the role of temporary storage in interactive evolution

In typical implementations of interactive evolution of aesthetic material, population size and generation count are limited due to the time-consuming manual evaluation process. We show how a simple device can help to compensate for this, and help to enhance the functionality of interactive evolution. A temporary storage, defined as a number of easily accessed memory locations for evolved objects, adjacent to the evolving population, can be regarded as a non-evolving extension of the population. If sufficiently integrated into the workflow, it provides compensation for limited genetic diversity, an analogy to elitism selection, and means to escape from stagnation of progress through backtracking and reintroduction of previous genomes. If used in a structured way, it can also help the user form a cognitive map of the search space, and use this map to perform a structured, hierarchical exploration. The discussion is based on experiences from a series of implementations of interactive evolution of music and sound, but should be relevant also for other forms of artistic material.