Judgment and Decision Making - PSYC 363

Crocodile vs. Alligator
- Common Features:
- Both are reptiles
- Possess sharp teeth
- Carnivorous diet
- Lay eggs
- Adapted to swamps
- Long lifespan (70-100 years in captivity)
- Distinctive Features:
- Snout shape varies
- Habitat preference: Freshwater vs. Brackish water
- Geographic location differences
- Different speeds on land
- Nesting sites vary
- Skin color traits differ
Elephant vs. Alligator
- Common Features:
- Excellent swimmers
- Ancient lineage as species
- Large body size
- Maternal care for their young
- Territorial nature
- Long longevity
- Distinctive Features:
- Reptile (Alligator) vs. Mammal (Elephant)
- Cold-blooded (Crocodile/Alligator) vs. warm-blooded (Elephant)
- Size and weight differences between species
- Habitat variations (aquatic vs. terrestrial)
- Differences in their social structures
- Disparities in brain size

Venn Diagrams
- Used to illustrate common and distinctive features between species.

Formula: S(a,b) = xf(a,b) - yf(a-b) - zf(b-a)
- Explanation:
- $S$ represents an interval scale of similarity
- Function $f$ reflects feature salience
- Parameters $x$, $y$, and $z$ adjust the weight given to different features.
Example:
- Comparing the similarity of two countries, e.g., Mexico and the USA

UMD Student Data (Winter 2024)
- Students rated the similarity of North Dakota to Michigan and vice versa:
- Michigan to North Dakota: Average = 4.375 on a scale of 1-10
- North Dakota to Michigan: Average = 5.0 on the same scale

Normative (Prescriptive) Approach:
- Counts the number of ways an event can occur using:
  P(x) = rac{n!}{(n-x)! x!}
- This accounts for the total number of combinations and success probability in multiple trials.
Representativeness Heuristic (Kahneman & Tversky, 1972):
- Evaluates a sample's probability by its similarity to the target population.
- Example probabilities:
- Outcomes such as p(X) = rac{1}{32} or p(X) = rac{1}{1296} imply how people perceive likelihood based on representativeness instead of statistical probability.

Law of Small Numbers:
- Describes the tendency of gamblers to believe results will even out over short series in lotteries, affecting bets over time.

Base-Rate Estimation
- Individuals often ignore the base rate information (general prevalence) in favor of similarities, leading to inaccuracies in judgment.

The probability of combined events is often judged to be more probable than either of the individual events.
Example:
- Ranking scenarios for an individual named Linda shows biases in assessing her likelihood of fulfilling combined criteria.

Recalls specific data influences judgments of frequency and probability, influenced by the ease of retrieval.

Assesses risk by common, media-represented events rather than by raw statistics, noting how dramatic events lead to overestimating certain risks.

The assumption that individuals should evaluate the same information equally, regardless of how presented.
Example scenarios to illustrate preferential biases based on phrasing or framing of choices.

Impact of presentation:
- A penalty vs. a discount can yield differing student registration behaviors.

Ratio-Difference Principle:
- The perceived value of changes in rates is more significant in relation to existing magnitudes rather than their absolute difference.

Summary: “Losses loom larger than gains”, indicating stronger emotional responses to losses than equals to gains.

Topics covered include:
- Similarity judgments, contrast models, probability judgments, heuristics, rational choice theory, and framing effects, which all impact decision-making processes.