16.422 Human Supervisory Control Classical Decision Theory &e bayes'Theorem Massachusetts Institute of Technology
16.422 Human Supervisory Control Classical Decision Theory & Bayes’ Theorem
Decision Theory supervisory Control 16.422 TWo broad areas of decision theory Normative Prescriptive Descriptive Why how do we make decisions? How does technology support or detract from optimal decision making Informing Design Normative. how decisions should be made Prescriptive: How decisions can be made, given human limitations Descriptive: How decisions are made
Decision Theory & Supervisory Control • Two broad areas of decision theory – Normative • Prescriptive – Descriptive • Why & how do we make decisions? – How does technology support or detract from “optimal” decision making • Informing Design 16.422 • Normative: How decisions should be made • Prescriptive: How decisions can be made, given human limitations • Descriptive: How decisions are made
Elements of Decision Making 16.422 The rational decision making process Define the problem Information gathering Identify alternatives Eⅴ aluate alternatives Select and implement decision Why decisions often go wrong Certainty vS uncertainty Bounded rationality nonlinearity Habits heuristics Path of least resistance
Elements of Decision Making 16.422 • The rational decision making process – Define the problem – Information gathering – Identify alternatives – Evaluate alternatives – Select and implement decision • Why decisions often go wrong: – Certainty vs. uncertainty – Bounded rationality – Nonlinearity – Habits & heuristics – Path of least resistance
Classic Decision Theory 16.422 Maximizing expected value of the outcome Primary assumption of rationality Mathematical models of human decision making Following assumptions are made about how people make decisions All alternatives are considered Information acquisition is perfect Probabilities are calculated correctly · Problems: Humans are not rational decision makers No universal agreement on the worth associated with various outcomes
Classic Decision Theory • Maximizing expected value of the outcome – Primary assumption of rationality • Mathematical models of human decision making • Following assumptions are made about how people make decisions: – All alternatives are considered – Information acquisition is perfect – Probabilities are calculated correctly • Problems: – Humans are not rational decision makers – No universal agreement on the worth associated with various outcomes. 16.422
Basic Concepts in Decision Analysis 16.422 State: a description of the world Events: A set of states S,s,,,S Consequences:A set of states Acts Results from decisions Act 1(A1)C Act 2(A2) 21 22
Basic Concepts in Decision Analysis 16.422 • State: A description of the world • Events: A set of states {S 1, S 2,…, S j } • Consequences: A set of states • Acts: Results from decisions S 1 S 2 Act 1 (A 1) C11 C12 Act 2 (A 2) C21 C22
Basic terminology 16.422 Ordering of preferences Alternatives can be quantified and ordered A>B, A preferred to B a=B. A is equivalent to b a> B, B is not preferred to a Transitivity of preference ifA1>A2,&A2≥A3, then a1≥A3
Basic Terminology 16.422 • Ordering of preferences – Alternatives can be quantified and ordered – A > B, A preferred to B – A = B, A is equivalent to B – A ≥ B, B is not preferred to A • Transitivity of preference – i f A1 ≥ A 2, & A2 ≥ A 3, then A1 ≥ A 3
Decision trees 16.422 Decisions over time and or events 11 2 Decision 2 Chance A 22 Nodes
Decision Trees 16.422 • Decisions over time and/or events Decision Node S 1 S 2 C11 C12 C21 C22 A 2 A1 A1 Chance A 2 Nodes
Decision making Under certainty 16.422 Each alternative leads to one and only one consequence Consequences are known Lexicographic ordering Dominance Satisficing Maximin · Minimax
Decision Making Under Certainty 16.422 • Each alternative leads to one and only one consequence – Consequences are known • Lexicographic ordering • Dominance • Satisficing • Maximin • Minimax
Lexicographic Ordering 16.422 All options are first compared in terms of the criterion deemed most important If there is a unique best performing option, that option is selected as the most preferred In case of a tie the selection process moves to the second ranked criterion Seeks the remaining option which scores best on the second criterion In case of a tie on the second criterion, the process is repeated for options tying in terms of both the first and second ranked criteria And so on until a unique option is identified or all criteria have been considered
Lexicographic Ordering 16.422 • All options are first compared in terms of the criterion deemed most important. – If there is a unique best performing option, that option is selected as the most preferred. • In case of a tie, the selection process moves to the second ranked criterion – Seeks the remaining option which scores best on the second criterion. • In case of a tie on the second criterion, the process is repeated for options tying in terms of both the first and second ranked criteria, – And so on until a unique option is identified or all criteria have been considered
Dominance 16.422 Effective for both quick qualitative and quantitative comparisons In the real world, solutions rarely are outwardly dominant A S333 020 A3
Dominance 16.422 • Effective for both quick qualitative and quantitative comparisons • In the real world, solutions rarely are outwardly dominant S1 S2 S3 S4 1 3 3 3 2 0 2 2 0 A1 0 A2 0 A3 -1