Complexity

• Planning is an ill defined task.
• It really depends on what you're trying to do.
• The blocks world is a toy domain, but robots, for example, often need to plan.
• The get directions applications have to do this.
• If you want to plan, it can often be an intractible problem.
• If it's intractible, or big, heuristics can often help.
• It may also not be possible to plan a solution.
• It is also possible to interleave human interaction with machine solutions.
• This can use the advantages of both humans and machines.