Goal attaining systems

I came across an interesting categorisation of goal attaining systems today:

• Goal-achieving; a system that recognises when a goal state has been reached. This can be implicit. Examples include a doorbell buzzer, or flowers opening up in the sun.
• Goal-seeking; a system that is such that it will move towards a goal state without any recognition that the goal is being worked towards. Examples include a marble spinning in a bowl, which will ultimately come to rest in the middle.
• Goal-directed; a system that has a representation of the goal state and it's behaviour is intended to bring about. This is a system with feedback control. Examples include a thermostat, and human planning.

This is a useful set of categories that can be utilised in thinking of philosophical entities and systems, and for the design of software agents, applications, and robots. It came to me via David McFarland's Guilty Robots, Happy Dogs: The Question of Alien Minds.