Engineering Psychology: Understanding Decision Making and Human Performance - Lecture 18 -, Study notes of Psychology

Download Engineering Psychology: Understanding Decision Making and Human Performance - Lecture 18 - and more Study notes Psychology in PDF only on Docsity! 1 1 Engineering Psychology & Human Performance Review: – Long-Term Memory & Training – Recognition vs. Recall: Knowledge in the World vs. Knowledge in the Head – Cognitive Heuristics in Decision Making: Representativeness and Availability Outline of Lecture 18 – Decision Making: Forming Inferences – Bayes Theorum – Evaluating Inferences: Anchoring and Confirmation Bias – Logical Reasoning 2 Forming Inferences Representativeness & Availability and human inferential abilities – These heuristics affect the manner in which hypotheses and inferences are formed – Hypotheses are chosen based on Bottom-up processing – current data suggest or deny a hypothesis – representativeness heuristic affects this process Top-down processing – previous experience (knowledge of prior probabilities) helps determine relevant hypotheses – affected by both representativeness & availability 3 – Model of optimal inference: Bayes’ Theorum Given 2 competing hypotheses H1 and H2, what is the probability of either hypothesis being correct given the data (D); i.e., P(H1/D) and P(H2/D) Forming Inferences odds = prior x likelihood odds ratio Human (non-optimal) inference – Representativeness affects perception of likelihood ratio – Representativeness and availability affect perception of prior odds )/( )/( )( )( )/( )/( 2 1 2 1 2 1 HDP HDP HP HP DHP DHP ×= 4 Evaluating Inferences Which sequence produces the larger #? 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 Anchoring and Adjustment Heuristic 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 (median est.= 2250) 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 (median est.= 512) (both are 40320) – We tend to emphasize the first information we receive when making decisions -- it anchors us – adjustments are made upon receiving additional information, but not large enough to compensate 5 Evaluating Inferences Causes of Anchoring and Adjustment – primacy effect and proactive interference? – Salience, simplicity, and cost vs. utility we tend to anchor on information that is – salient (e.g., information that comes first) – simple (e.g., nurses medical decisions) – cheap we don’t anchor based on utility of information as if heuristic: treat all information as if it is equally diagnostic and reliable – Human insensitivity to absence of information 6 Evaluating Inferences Causes of anchoring and adjustment (cont.) – Confirmation Bias: more weight given to evidence consistent with favored hypothesis than to evidence supporting the contrary hypothesis cognitive “tunnel vision” effect is enhanced under high stress or mental workload – Why? 2 7 Evaluating Inferences – Causes of confirmation bias difficulty processing negative information – humans process positive information more rapidly than negative information – Clark & Chase (1972) sentence verification task The O is above the + (true, affirmative): 1744 ms The + is above the O (false, affirmative): 1959 ms The + is not above the O (true, negative): 2624 ms The O is not above the + (false, negative): 2470 ms – Statements that contain negatives take longer – Spatial congruence between picture order (top to bottom) and word order (left to right) speeds processing (1st and 4th situations) + 8 Evaluating Inferences – Causes of confirmation bias (cont.) Changing hypotheses exerts a high cognitive workload Ego-investment – top-down effect – self -fulfilling prophecy 9 Evaluating Inferences Biases in Deductive Reasoning – Task: evaluate whether a logical argument is valid – Structure of conditional reasoning Premise 1: IF <antecedent> THEN <consequent> Premise 2: <antecendent> (or <consequent>) true or false Conclusion: is <consequent> (or <antecedent>) true or false? 10 Evaluating Inferences Premise 1: If I study for the exam I will pass Premise 2: I studied for the exam Conclusion: I will pass the exam Is the conclusion valid or invalid? Propositional Calculus 11 Evaluating Inferences – Propositional Calculus (4 possibilities) Affirming the antecedent (valid) – I studied for the exam, therefore I will pass Affirming the consequent (invalid) – I passed the exam, therefore I studied Denying the antecedent (invalid) – I didn’t study for the exam, therefore I won’t pass Denying the consequent (valid) – I didn’t pass the exam, therefore I didn’t study 12 Evaluating Inferences – Human Performance easiest to confirm validity of affirming the antecedent next best at confirming the validity of denying the consequent worst at disconfirming invalid reasoning – Why are humans bad at this? Difficulty with negative information Belief -bias effect – judgments based on prior belief rather than logic – case of “common sense” overcoming logic constructing only one model of the premises – anchoring and confirmation bias