Monday, March 22, 2010

The semantic abyss: reality vs. our perception and our models

From the very moment we first open our eyes or first hear some sound or first touch anything we feel that we are experiencing the world around us and that we know that world, reality, but do we? Given enough experience, we gradually realize that some if not many of our earlier perceptions are not completely in accord with reality as it really exists. So, the most basic conception of the Semantic Abyss is that we have two worlds to deal with: 1) the real world, reality itself, and 2) the perceived world, our mental model of what we think or imagine the real world is.

We actually have a third and fourth world to deal with: 3) a model of the real world constructed from conceptions based on our perceptions that we can express to others, and 4) the models of the world that others have constructed and endeavored to communicate to us.

Somehow, we merge, mesh, and blend these three models and derive a composite model of the real world.

Over time and with enough input with enough diversity we come up with ever-better models that better represent the reality of the real world, but despite our best efforts, there will always be a lingering Semantic Abyss between the real world as it really is and our best mental model of what the world is.

Another issue is that even when we are fortunate enough to establish a workable one-to-one correspondence between the real world and our mental model of the real world, there is no guarantee that each correspondence of reality and mental model is accurate and rich enough to adequately model the full complexity of the real world.

A final issue is that we wish to share our models with computers and other artificial entities (e.g., robots which seek to move around and interact with the real world) so that computer programs can make sense of the real world, either in terms of recorded data or real-time sensor data.

In short, we deal with four models of the real world:

  1. The real world as it is that we can observe and interact and experiment with.
  2. Our perception and internal conception of the real world.
  3. The communicable model of the real world that we share with each other.
  4. Computer models of the real world which can be readily manipulated by computer programs.

There are plenty of gaps between those four models of reality that we need to cope with when dealing with knowledge of the real world.

-- Jack Krupansky