Improving judgment accuracy by sequential adjustment

Judging an object’s value based on relevant cues can be challenging. We propose a simple method to improve judgment accuracy: Instead of estimating a value after seeing all available cues simultaneously, individuals view cues sequentially, one after another, making and adjusting their estimate at each step. The sequential procedure may alleviate computational difficulties in cue integration, leading to higher judgment accuracy. We tested this hypothesis in two real-world tasks in which participants judged either the price of diamonds or the fuel economy of cars. Two studies with professional jewelers and car salespeople show that most participants indeed judged more accurately with a sequential than with a simultaneous procedure. Another two studies with college students further support this finding and show additionally that the sequential procedure could raise the judgment accuracy of inexperienced students to the same level as that of professionals judging with the simultaneous procedure.

     

Choice reaction and unequal stimulus frequencies in an absolute judgment situation

Previous investigators have reported discrepant results for Ss in a choice reaction time (CRT) situation when stimuli are not equi-probable. Sixty Ss participated in an absolute judgment CRT task under three conditions of equi-probable stimuli and three of unequally probable stimuli. The results indicate that previous findings may be determined by a threshold dependent upon the effect of unequal stimulus frequencies and the utilities of different response strategies.     

Dissociating speed and accuracy in absolute identification: the effect of unequal stimulus spacing

Identification accuracy for sets of perceptually discriminable stimuli ordered on a single dimension (e.g., line length) is remarkably low, indicating a fundamental limit on information processing capacity. This surprising limit has naturally led to a focus on measuring and modeling choice probability in absolute identification research. We show that choice response time (RT) results can enrich our understanding of absolute identification by investigating dissociation between RT and accuracy as a function of stimulus spacing. The dissociation is predicted by the SAMBA model of absolute identification (Brown, Marley, Dockin, & Heathcote, 2008), but cannot easily be accommodated by other theories. We show that SAMBA provides an accurate, parameter free, account of the dissociation that emerges from the architecture of the model and the physical attributes of the stimuli, rather than through numerical adjustment. This violation of the pervasive monotonic relationship between RT and accuracy has implications for model development, which are discussed.

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The delayed stimulus suffix effect following arhythmic stimulus presentation

In auditory memory span experiments an extra word presented at the end of the list impairs performance on the last few items even though it is completely redundant; delaying this stimulus suffix past the time when an additional memory item would have occurred--so that the rate of presentation is retarded for the suffix--reduces the magnitude of the performance impairment. One account of this pattern of results is that during presentation of the items the subject adjusts periodic bursts of attention to the regular cadence of new information. Since an immediate suffix is in time with this cadence and a delayed suffix not, the larger effect of the former is explained without appeal to any process dependent on real time. In the present study the stimulus items were presented in an arhythmic manner with interstimulus intervals ranging from 100 to 900 ms on a random basis. Under these conditions the same effect of delaying the suffix was observed as is typical of rhythmic stimulus presentation; therefore, the rhythm hypothesis for the effect is not supported.     

Choice reaction and unequal stimulus frequencies in an absolute judgment situation

Previous investigators have reported discrepant results for Ss in a choice reaction time (CRT) situation when stimuli are not equi-probable. Sixty Ss participated in an absolute judgment CRT task under three conditions of equi-probable stimuli and three of unequally probable stimuli. The results indicate that previous findings may be determined by a threshold dependent upon the effect of unequal stimulus frequencies and the utilities of different response strategies.     

Hierarchical switching with two types of judgment and two stimulus dimensions

A number of recent studies have shown that shifting among four tasks that result from a factorial combination of two types of judgment with two judgment-to-response mappings results in a characteristics pattern of shift costs that indicates a hierarchical representation of the two task features judgment and mapping (e.g., Kleinsorge & Heuer, 1999). In the present study, two types of judgment were combined with two stimulus dimensions. With this task combination, the same basic shift-cost pattern was observed. This suggests that a combination of two types of judgment with two stimulus dimensions also results in a hierarchically structured task representation, indicating that such a task representation is readily adopted by participants when the combination of task features is suitable for a hierarchical organization.     

Probing Proctor's priming principle: the effect of simultaneous and sequential presentation on same-different judgments

Three explanations (internal noise, priming, relative frequency) of the fast-same effect were examined. The internal-noise principle, which predicts more errors as well as faster correct judgments on same pairs, was consistently confirmed even with sequential presentation. More elusive was priming, that is, the facilitation of encoding from letter repetition with sequential presentation. Priming was inhibited by the presence of intertrial letter repetition. The error data indicated that priming involves an increased efficiency in encoding (d'), as Proctor claimed, rather than a criterion shift (beta), as Krueger and Shapiro claimed. An alternative to the priming explanation, based on the greater susceptibility of simultaneous presentation to analytical processing, was tested and disconfirmed. Stimulus-set size did not affect the speed advantage for same pairs, thus disconfirming the relative-frequency explanation, according to which same judgments are faster because typically there are fewer unique same than different pairs.     

The effect of divided attention on global judgment of learning accuracy

This study examined the effect of divided attention (DA) on global judgment of learning (JOL) accuracy in a multitrial list learning paradigm. A word monitoring task was used to divide attention. Participants were assigned to an attention condition (DA at encoding, DA at judgment, DA at retrieval, or focused attention) and completed 4 learning trials, each comprising a study, judgment, and recall phase. Participants showed greater overconfidence in the DA at encoding (Trial 2) and DA at retrieval (Trials 1 and 2) conditions than in the focused attention condition. DA atjudgment did not affect JOL accuracy, and there was no effect of DA in Trials 3 and 4 on JOL accuracy across all attention conditions. Results indicate that participants consider conditions of encoding and retrieval but do not engage in recall when forming global JOLs. These findings suggest that people rely on extrinsic cues when making repeated, global metamemoryjudgments.     

Information integration and the identification of stimulus noise and criterial noise in absolute judgment

Two main classes of theories have been proposed regarding range effects in unidimensional absolute-identification tasks. One class posits that as range is increased, criterial noise increases but stimulus noise remains constant. Another class posits increasing stimulus noise but constant criterial noise. In this study, an effort is made to help decide this issue. Multiple observations are used in several absolute-identification tasks of varying range. A stimulus integration model is proposed in which averaging takes place over stimulus internal representations, thereby reducing stimulus variance; on the other hand, it is assumed that criterial variance is unaffected by the number of observations. The model allows one to identify the relative amounts of stimulus noise and criterial noise inherent in observers' recognition judgments. The model yields good fits to data in several experiments, and it is concluded that both stimulus noise and criterial noise increase as range in the absolute-identification task is increased.     

The effect of interstimulus interval on sequential effects in absolute identification

In absolute identification experiments, the participant is asked to identify stimuli drawn from a small set of items which differ on a single physical dimension (e.g., 10 tones which vary in frequency). Responses in these tasks show a striking pattern of sequential dependencies: The current response assimilates towards the immediately preceding stimulus but contrasts with the stimuli further back in the sequence. This pattern has been variously interpreted as resulting from confusion of items in memory, shifts in response criteria, or the action of selective attention, and these interpretations have been incorporated into competing formal models of absolute identification performance. In two experiments, we demonstrate that lengthening the time between trials increases contrast to both the previous stimulus and the stimulus two trials back. This surprising pattern of results is difficult to reconcile with the idea that sequential dependencies result from memory confusion or from criterion shifts, but is consistent with an account that emphasizes selective attention.     

The effect of blocking inter-trial interval on sequential effects in absolute identification

Sequential effects are ubiquitous in decision-making, but no more than in the absolute identification task where participants must identify stimuli from a set of items that vary on a single dimension. A number of competing explanations for these sequential effects have been proposed, and recently Matthews and Stewart [(2009a). The effect of inter-stimulus interval on sequential effects in absolute identification. The Quarterly Journal of Experimental Psychology, 62, 2014–2029] showed that manipulations of the time between decisions is useful in discriminating between these accounts. We use a Bayesian hierarchical regression model to show that inter-trial interval has an influence on behaviour when it varies across different blocks of trials, but not when it varies from trial to trial. We discuss the implications of both our and Matthews and Stewart's results on the effect of inter-trial interval for theories of sequential effects.     

Age differences in switching the relevant stimulus dimensions in a speeded same-different judgment paradigm

The present study employed a same-different judgment task-switching paradigm to re-examine the effects of age on switch costs. We manipulated perceptual and conceptual dimensions to serve as the criteria for making a same-different judgment. We also manipulated a short versus long cue-stimulus interval, while keeping the response-stimulus interval constant in order to examine whether older adults can benefit from longer preparatory intervals. The results indicate that older adults exhibited larger switch costs. In contrast to this impairment, older adults maintained the ability to prepare for an upcoming task switch. Nevertheless, even with a long preparatory interval, older adults still exhibited larger switch costs than younger adults. A more detailed analysis using a mixture model technique suggests that older adults' elevated residual costs in performing perceptual-judgment switches might be attributable to an increased probabilistic failure to complete advance preparation, whereas older adults' elevated residual costs in performing conceptual-judgment switches might be attributable to an intrinsic limitation in their ability to attain a complete task-set reconfiguration during a preparatory interval.     

The relationship between Eysenck's major personality dimensions and simultaneous and sequential processing in children

The present study reexamined Eysenck's hypothesis that intelligence and personality are uncorrelated. Intelligence was measured with the Kaufman Assessment Battery for Children, yielding scores for simultaneous and sequential processing and achievement, and the Woodcock-Johnson Brief Scale. Personality was assessed with the Junior Eysenck Personality Questionnaire. Ss were 105 children, ages 8$\text{1}\text{2}$10$\text{1}\text{2}$yr. Although a process as well as a product-oriented intelligence test was employed, the correlational and discriminant analyses supported Eysenck's original hypothesis.     

The bow and sequential effects in absolute identification

The bow and sequential effects in absolute identification are investigated in this paper by following two strategies: (1) Experiments are performed in which sequential dependencies in signal presentations are manipulated, and 12) analyses are conducted (some of which are largely free of model-specific assumptions) which bear directly on the question of the origin of the sequential effects. The main result of the study is that absolute identification performance is greatly improved in a design in which each signal lies close to the preceding signal presented, even though the entire range of signals used is the same as in a random presentation design. This finding is consistent with the attention-band model of Luce, Green, and Weber (1976) and rejects hypotheses that suggest that the variability in the signal representation in absolute identification is a function solely of the range of signals being used. However, nonparametric analyses of sequential response errors show that a plausible assumption concerning the trial by-trial movement of the attention band provides an incomplete explanation of Seluential effects in absolute identification. These results are far better explained in terms of systematic shifts of category boundaries in a Thurstonian model, as suggested by Purks, Callahan, Braida, and Durlach (1980). Experiments are also performed which suggest that memory decay is not the major factor accounting for the bow effect in absolute identification.     

The effect of simultaneous versus serial responding on children's ability to coordinate two dimensions

Previous research by Lidster and Bremner (1999) on young children's ability to coordinate two dimensions has shown that performance on construction tasks (in which children have to give the correct coordinates for a point in space that is already known) is superior to performance on interpretation tasks (in which children are given a pair of coordinates and have to locate the correct point in space on the basis of these). The present study investigates the suggestion made by Lidster and Bremner that construction tasks may be easier due to the possibility that they can be solved by attending to only one dimension at a time. In this experiment 84 children between the ages of 3 and 6 years were given 16 trials of a construction task, which they were either asked to do by moving two pointers simultaneously or by moving the pointers sequentially. Overall there was no main effect of condition. However, some trials were affected by condition. These results are discussed in relation to Lidster and Bremner's suggestions and Huttenlocher, Newcombe, and Sandberg's (1994) claims regarding the development of spatial understanding.