Novelty Distance
2 min read

Novelty Distance

I first came across the idea of novelty search via Kenneth O. Stanley’s YouTube talk Why Greatness Cannot Be Planned and the corresponding book. It’s an exploration algorithm that is driven by the novelty of behavior rather than an objective.

The most intriguing part of novelty search to me is its focus not on optimization but rather discovery. It’s not to say novelty search is a better search algorithm but that its application should be used to generate a different kind of result. Dr. Stanley explores in detail what novelty search means for an individual, so I will just briefly summarize here.

In our life we often set goals for ourselves and we measure our progress based on whether or not we achieve those goals. More recently, the concept of moonshotshas gained a lot of popularity. To answer the question of “why haven’t we been able to achieve more?” moonshots is given as the reason. We haven’t set ambitious enough goals and so all that we can hope to achieve is incremental progress.

What Dr. Stanley realized through his research in artificial intelligence, however, is that setting goals is actually the cause of incremental progress not the result. Innovative discoveries are the result of many incremental achievements which Dr. Stanley refers to as “stepping stones”. We were able to develop computers and televisions only because we had already invented vacuum tubes. We were only able to create the personal computer through the invention of the transistora couple of decades before.

But what about the original moonshot, the one where president John F. Kennedy set the goal of sending humans to the Moon and back again in 1961 which was achieved only eight years later? It’s actually not a counterexample… The Apollo program certainly created many new stepping stones that paved the way for other innovations. But the timing of the program was actually not as far (or distant) away as it may have seemed in 1961. Many of the stepping stones required for the Apollo program to succeed was already well under way. What if instead of president Kennedy it had been president Theodore Roosevelt who had made the declaration in 1901, only 60 years prior? The program would have almost certainly failed. The Apollo program’s distance from reality in 1901 was simply too large compared to its distance in 1961.

This is where novelty distance comes in. Novelty distance is the distance between current reality and some future outcome. You can think of it as sort of a Levenshtein distance, except the actual metric for distance is likely not calculable.

One fun thought experiment you can do with novelty distance is to imagine a traveler from the future telling you about an exceedingly rare future outcome for yourself. For example, maybe in the future you discover the cure for cancer. The novelty distance is essentially how incredulous it would make you feel.

I am not sure how practical novelty distance is for helping you to plan your life or career. At the very least though, maybe it’s worthwhile trying to live a life where if you ever meet that time-traveler you aren’t so shocked to hear about the accomplishments of a future version of yourself.