the psychology of planning

Question 1

what is planning?

Answer 1

• Planning - deciding on the order and intensity of decomposition of problem, and determining consequences of alternative plans
  
  • Planning involves search through the problem space
  • Search is guided by heuristics
  • Planning is constrained
  • Planning is mediated by external environments

Question 2

what is planning - problem components

Answer 2

• Initial state - the problem as presented
  
  • Goal state - the aim/intention/desired outcome
  • Operators - things you can do/try/execute
• Constraints - limitations on what you can do/try/execute, additional requirements/rules

Question 3

what is planning - problem decomposition

Answer 3

• “Design may be the ultimate expression of human thought” (Simon, 1981)
  
  • Complex, multi-faceted
  • Constrained by domain, brief, market and tradition
  • Requiring an element of creativity, sometimes novelty

Question 4

what is planning - decomposition orders

Answer 4

• Breadth-first:
  
  • Advantage - minimal commitment
  • Depth-first:
  • Advantage - immediate feedback; lower cognitive load
  • Opportunistic:
  • Capitalising on current state

Question 5

what is planning - the problem space

Answer 5

· The mental representation of a problem
- State space
- Task environment
- Information processing system

Question 6

the state space

Answer 6

· All possible paths between initial and goal states
· The larger it is, the harder a problem will be to solve
· Newell and Simon (1972) - concepts of ‘bounded rationality’ and satisficing
· Towers of Hanoi

Question 7

task environment

Answer 7

· The way a problem is presented to the solver:
- Format - display type
- Thematic content - e.g., familiarity
- Conditions - e.g., criticality; risk

Question 8

information processing system

Answer 8

· Working memory:
- Constraint on planning steps
- Chess - from any given position there are on average 35 possible moves. If a chess game lasts 100 moves = 35100 possible moves. Impossible to calculate
· Long-term memory:
- Knowledge of solutions, operators and constraints
- Expertise

Question 9

what is planning - search using heuristics

Answer 9

· Means-ends analysis
- E.g., fix a car tyre
- Make situation safe; Remove wheel; Loosen nuts; Raise car; Undo nuts; Slide wheel off; Replace wheel, lower car; tighten nuts, etc.
· Operator selection
- Select operator that maximises reduction of distance between initial and goal states
- Set as ‘sub-goal’ to apply the operator

Question 10

means-ends analysis and the TOH

Answer 10

· Goal – move all three disks from A to C
· Operator – move disks 3 then 2 then 1 to C
- Subgoal – move 2 then 1 to C
- Subgoal – move 1 to C
· BUT this can lead to a wrong move (1 to B so you can move 2 to C faster)
- -> planning (i.e. thinking ahead)

Question 11

other heuristics

Answer 11

· Means-ends analysis
· Hill-climbing
· Trial and error
· Heuristics for sampling
- Anchoring
- Representativeness
- Etc

Question 12

what happens when we dont plan

Answer 12

· Act first, think later: effects of maximisation, minimisation and lookahead on inferential planning in problem-solving