Absolute Frequency Identification: How a Sequence of Events can Affect People's Judgements

Theories of absolute identification and categorization established over past decades have revealed people’s inability to classify or judge perceived objects independently of their context. Our series of experiments shows that judged frequencies of sequentially encountered stimuli are affected by certain properties of the sequence configuration: Representations of a category do not only depend on (1) the number of stimuli/chunks in the sequence (2) the relation of the current stimulus to the immediately preceding stimulus, and (3) relations between stimuli further back versus recent stimuli but also on (4) simple sequence characteristics. Specifically, a first-run effect occurs whereby people overestimate the frequency of a given category of event when that category is the first repeated category to occur in the sequence. While current theories of absolute identification and categorization cannot account for these results, the simplicity framework, suggested in this paper, accounts for this and other context effects on judgment tasks

Taking Precautions is Not the Same as Choosing Gambles: Prospect Theory and the Use of Probability in Risky Choices

In four experiments we studied precautionary decisions where participants decided whether or not to adopt a specified precaution with a known cost in the face of a described risk. We find that both the weighting function and the value function required to model these decisions exhibit different properties for precautionary decisions than those observed for choices between gambles. Overweighting of probability is observed for moderate and high probabilities – a finding not anticipated by Prospect theory. Our results highlight a need for differentiation between models to account for precautionary behavior and models of other types of decision-making under risk\uncertainty

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

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

Modeling judgment of sequentially presented categories using weighting and sampling without replacement

In a series of experiments, Kusev et al. (Journal of Experimental Psychology: Human Perception and Performance 37:1874–1886, 2011) studied relative-frequency judgments of items drawn from two distinct categories. The experiments showed that the judged frequencies of categories of sequentially encountered stimuli are affected by the properties of the experienced sequences. Specifically, a first-run effect was observed, whereby people overestimated the frequency of a given category when that category was the first repeated category to occur in the sequence. Here, we (1) interpret these findings as reflecting the operation of a judgment heuristic sensitive to sequential patterns, (2) present mathematical definitions of the sequences used in Kusev et al. (Journal of Experimental Psychology: Human Perception and Performance 37:1874–1886, 2011), and (3) present a mathematical formalization of the first-run effect—the judgments-relative-to-patterns model—to account for the judged frequencies of sequentially encountered stimuli. The model parameter w accounts for the effect of the length of the first run on frequency estimates, given the total sequence length. We fitted data from Kusev et al. (Journal of Experimental Psychology: Human Perception and Performance 37:1874–1886, 2011) to the model parameters, so that with increasing values of w, subsequent items in the first run have less influence on judgments. We see the role of the model as essential for advancing knowledge in the psychology of judgments, as well as in other disciplines, such as computer science, cognitive neuroscience, artificial intelligence, and human–computer interaction

Leisure and work, good and bad:The role of activity domain and valence in modeling user experience

Recent research suggests that psychological needs such as competence and relatedness are involved in users’ experience with technology and are related to the perception of a product's hedonic and pragmatic quality. This line of research, however, predominately focuses on positive leisure experiences, and it is unclear whether need fulfillment plays a similar role in negative experiences or in other activity domains such as work. Therefore, this study investigates need fulfillment in positive and negative experiences, and in work and leisure experiences in two separate studies by analyzing almost 600 users’ experiences with technology along with ratings on need fulfillment, affect, and perceived product quality. Results suggest that work and leisure experiences as well as positive and negative experiences differ in terms of need fulfillment. Hence, both activity domain and valence of experiences are important factors that should be taken in account when modeling user experience.</jats:p

Exaggerated Risk: Prospect Theory and Probability Weighting in Risky Choice

In 5 experiments, we studied precautionary decisions in which participants decided whether or not to buy insurance with specified cost against an undesirable event with specified probability and cost. We compared the risks taken for precautionary decisions with those taken for equivalent monetary gambles. Fitting these data to Tversky and Kahneman’s (1992) prospect theory, we found that the weighting function required to model precautionary decisions differed from that required for monetary gambles. This result indicates a failure of the descriptive invariance axiom of expected utility theory. For precautionary decisions, people overweighted small, medium-sized, and moderately large probabilities—they exaggerated risks. This effect is not anticipated by prospect theory or experience-based decision research (Hertwig, Barron, Weber, & Erev, 2004). We found evidence that exaggerated risk is caused by the accessibility of events in memory: The weighting function varies as a function of the accessibility of events. This suggests that people’s experiences of events leak into decisions even when risk information is explicitly provided. Our findings highlight a need to investigate how variation in decision content produces variation in preferences for risk

Isolation and characterisation of microsatellite loci for two species of Spinturnicid wing mites (Spinturnix myoti and Spinturnix bechsteini)

To investigate the potential for host-parasite coadaptation between bats and their wing mites, we developed microsatellite loci for two species of Spinturnix mites. For Spinturnix myoti, parasite of Myotis myotis, we were able to develop nine polymorphic loci and screened them in 100 mites from five bat colonies. For S. bechsteini, parasite of M. bechsteinii, we developed five polymorphic loci, which were also screened in 100 mites from five bat colonies. In both species, all markers were highly polymorphic (22-46 and 6-23 alleles per locus respectively). The majority of markers for both species exhibited departure from Hardy-Weinberg proportions (8 of 9 and 3 of 5, respectively). One marker pair in S. myoti showed evidence for linkage disequilibrium. As the observed departures from Hardy-Weinberg proportions are most likely a consequence of the biology of the mites, the described microsatellite loci should be useful in studying population genetics and host-parasite dynamics of Spinturnix myoti and Spinturnix bechsteini in relation to their bat hosts

Relative theory of choice: preference change for risky choices

In one experiment 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 (a) the weighting function required to model decisions with 'high-accessible' features in memory exhibits different properties to those required to model choices between monetary gambles and (b) the accessibility (Fox & Levav, 2000; Kahneman, 2003; Koriat, 2001) of events in memory affects choices between options, influencing participants' decision weights, but not their judgments of these options