Understanding vs comprehension: mechanical context

Definitions of understanding and comprehension as found on the web are often self referential or invoke other abstract words like meaning and knowledge. In a human context, I found these definitions unfulfilling; in a machine context, they ar not helpful at all.

I am trying to define two states of knowledge acquisition and processing that can be demonstrated by a childhood memory of mine. In 1977, I saw Star Wars in the theater. In the opening scene, A tiny consular ship is being fired on by a star destroyer. As a 5 year old, I understood that the big ship was trying to blow up the little ship. My comprehension of scene was that the small ship is the good guy and the big scary ship is the bad guy.

Understanding is about "what".
Simple understanding: The big ship is shooting at the little ship. Big ship is the bad guy, little ship is the good guy. Big ship, strong. Little ship, weak. Understanding is about ascribing qualities or assuming qualities based on analogs from previous experience.

Comprehension is about "why".
Simple comprehension: Big ship is chasing the little ship because the big ship wants to blow up the little ship. Complex comprehension: Darth Vader is on the big ship and wants to capture (not destroy) the little ship because someone on board has stolen plans to the death star. Deep Comprehension: why would it be necessary to find the plans aboard the ship when the technologically advanced people would be able to replicate and transmit the plans? Comprehension is a subset of understanding that is concerned with motivation and intended goals.

Another example: A bully beats up a boy and takes his lunch money. Another boy who witnessed the event understands that the bully beat up the boy. The witness comprehends that the bully beat the boy up to steal his money.

As understanding grows, so does the potential for comprehension, but the two are not lock step.

I realize that this is my first blog entry, but if you are reading is you will be keenly aware that you have walked into this movie in the middle.

I will restate this more thoroughly later, but my goal is to develop a simpler, more intuitive, more effective conversation engine. (Think Loebner prize winner but without canned responses.) I am trying to distil the mechanics of thought in order to produce a thinking machine.

more later...