Choice and human preferences: How accessibility, context and simplicity affect decision prospects

The leading normative (von Neumann & Morgenstern, 1947) and alternative psychological theories (e.g.,Tversky & Kahneman, 1992) of judgment and decision- making share a common representational assumption: people's preferences and decisions under risk and uncertainty are task-independent. For example, these theories assume that all decisions under risk or uncertainty can be represented as gambles with monetary amounts representing the outcomes. In five experiments we studied the extent to which theories of judgment, decision-making and memory can predict people's preferences. We find that (a) the weighting function required to model decisions with 'high-accessible' features in memory exhibits different properties from those required to model choices between monetary gambles and (b) the accessibility (Koriat & Levy-Sadot, 2001) of events in memory affect choices between options, influencing participants' decision weights, risk preferences and choice consistency. These results indicate a failure of the descriptive invariance axiom of Expected Utility Theory and challenge those psychological theories predicting a particular pattern of preferences for all risky prospects. We highlight a need for theories which differentiate between decisions about monetary gambles and other types of decision-making under risk and uncertainty

How to discriminate between computer-aided and computer-hindered decisions: a case study in mammography

Background. Computer aids can affect decisions in complex ways, potentially even making them worse; common assessment methods may miss these effects. We developed a method for estimating the quality of decisions, as well as how computer aids affect it, and applied it to computer-aided detection (CAD) of cancer, reanalyzing data from a published study where 50 professionals (“readers”) interpreted 180 mammograms, both with and without computer support. Method. We used stepwise regression to estimate how CAD affected the probability of a reader making a correct screening decision on a patient with cancer (sensitivity), thereby taking into account the effects of the difficulty of the cancer (proportion of readers who missed it) and the reader’s discriminating ability (Youden’s determinant). Using regression estimates, we obtained thresholds for classifying a posteriori the cases (by difficulty) and the readers (by discriminating ability). Results. Use of CAD was associated with a 0.016 increase in sensitivity (95% confidence interval [CI], 0.003–0.028) for the 44 least discriminating radiologists for 45 relatively easy, mostly CAD-detected cancers. However, for the 6 most discriminating radiologists, with CAD, sensitivity decreased by 0.145 (95% CI, 0.034–0.257) for the 15 relatively difficult cancers. Conclusions. Our exploratory analysis method reveals unexpected effects. It indicates that, despite the original study detecting no significant average effect, CAD helped the less discriminating readers but hindered the more discriminating readers. Such differential effects, although subtle, may be clinically significant and important for improving both computer algorithms and protocols for their use. They should be assessed when evaluating CAD and similar warning systems

Memory-Biased Preferences: How Accessibility Affects Judgments and Decision-Making Prospects

The leading normative (von Neumann & Morgen- stern, 1947) and descriptive psychological theories (e.g., Birnbaum, 2008; Brandstätter et al., 2006; Tversky & Kahneman, 1992; Tversky & Koehler, 1994) of judgment and decision making share a common representational assumption: People’s preferences and decisions under risk and uncertainty are task-independent. In five experiments, we studied the extent to which theories of judgment, decision making, and memory can predict people’s preferences. Applying prospect theory and support theory to these data, we find that (1) the weighting function required to model decisions with high-accessible features in memory exhibits different properties than those required to model choices between monetary gambles, and (2) the acces- sibility (Fox & Levav, 2000; Kahneman 2003; Koriat, 2001) of events in memory affects choices between options, influencing participants’ deci- sion weights, but not their judgments of these options. This result indicates a failure of the descriptive invariance axiom of expected utility theory

An analytical and experimental investigation of aerofoil-turbulence interaction noise for plates with spanwise-varying leading edges

This paper presents an analytic solution for gust–aerofoil interaction noise for flat plates with spanwise-varying periodic leading edges in uniform mean flow. The solution is obtained by solving the linear inviscid equations via separation of variables and the Wiener–Hopf technique, and is suitable for calculating the far-field noise generated by any leading edge with a single-valued piecewise linear periodic spanwise geometry. Acoustic results for homogeneous isotropic turbulent flow are calculated by integrating the single-gust solution over a wavenumber spectrum. The far-sound pressure level is calculated for five test-case geometries; sawtooth serration, slitted $v$-root, slitted $u$-root, chopped peak and square wave, and compared to experimental measurements. Good agreement is seen over a range of frequencies and tip-to-root ratios (varying the sharpness of the serration). The analytic solution is then used to calculate the propagating pressure along the leading edge of the serration for fixed spanwise wavenumbers, i.e. only the contribution to the surface pressure which propagates to the far field. Using these results, two primary mechanisms for noise reduction are discussed; tip and root interference, and a redistribution of energy from cuton modes to cutoff modes. A secondary noise-reduction mechanism due to nonlinear features is also discussed and seen to be particularly important for leading edges with very narrow slits.</jats:p

Retrospective evaluations of sequences: Testing the predictions of a memory-based analysis

Retrospective evaluation (RE) of event sequences is known to be biased in various ways. The present paper presents a series of studies that examined the suggestion that the moments that are the most accessible in memory at the point of RE contribute to these biases. As predicted by this memory-based analysis, Experiment 1 showed that pleasantness ratings of word lists were biased by the presentation position of a negative item and by how easy the negative information was to retrieve. Experiment 2 ruled out the hypothesis that these findings were due to the dual nature of the task called upon. Experiment 3 further manipulated the memorability of the negative items – and corresponding changes in RE were as predicted. Finally, Experiment 4 extended the findings to more complex stimuli involving event narratives. Overall, the results suggest that assessments were adjusted based on the retrieval of the most readily available information

Judgments relative to patterns

Four experiments study relative frequency judgment and recall of sequentially presented items drawn from two distinct categories (e.g., cities, animals). The experiments show that judged frequencies of sequentially encountered stimuli are affected by certain properties of the sequence configuration. We find (a) a first-run effect whereby people overestimate the frequency of a given category when that category is the first repeated category to occur in the sequence and (b) a dissociation between judgments and recall; respondents may judge one event more likely than the other and yet recall more instances of the latter. Judged frequency of categories of items is influenced by the first run - which may reflect the operation of a judgment heuristic. The distribution of recalled individual items does not correspond to the frequency estimates, indicating that participants do not make frequency judgments by sampling their memory for individual items. We propose a simple strategy whereby respondents use the first run as a cue to frequency that accounts for this observation and other context effects on memory and judgment

Are people experiencing the ‘pains of imprisonment’ during the Covid-19 lockdown?

Background: By the end of March 2020, more than a fifth of the world’s population was in various degrees of ‘lockdown’ in order to slow the spread of Covid-19. This enforced confinement led some to liken lockdown to imprisonment. We directly compared individual’s experiences of lockdown with prisoners’ experiences of imprisonment in order to determine whether psychological parallels can be drawn between these two forms of confinement. Method: Online surveys of adults in lockdown in the UK (N = 300) and California (N = 450) were conducted four and five weeks into lockdown in each region, respectively. The UK data was then compared to Souza and Dhami’s (2010) sample of 267 medium security prisoners in England, and the Californian data was compared to Dhami et al.’s (2007) sample of 307 medium security Federal prisoners in California. We measured the effects of Group (Lockdown v. Prison) on five categories of dependent variables (i.e., activity, social contact, thoughts, feelings, and rule-breaking), controlling for demographic differences between the groups. Results: In both regions, people in lockdown thought significantly less often about missing their freedom, as well as missing their family and friends living elsewhere than did first-time prisoners. However, people in lockdown in both regions were also significantly less engaged in a range of daily activities than were first-time prisoners. Additionally, in both regions, people in lockdown reported feeling more hopeless than first-time prisoners. Conclusions: Although Governments introducing lockdown policies do not intend to punish their citizens as courts do when sending convicted offenders to prison, such policies can have unintended adverse consequences. Psychological parallels can be drawn between the two forms of confinement

The first-run effect: How temporal sequence patterns affect judgments and memory

Four experiments study relative frequency judgment and recall of sequentially presented items drawn from two categories (e.g. cities/animals). We find (a) a first-run effect whereby people overestimate the frequency of a given category when that category is the first repeated category to occur in the sequence and (b) a dissociation between judgments and memory; respondents may judge one event more likely than the other and yet recall more instances of the latter. Frequency judgements are influenced by the first run - which may reflect the operation of a judgment heuristic - while free-recall is influenced by later items