Frequency Judgments Research Articles

Errors and bias in assessments of danger and frequency of traffic situations

Six groups of nine drivers took part in a laboratory study which sought to investigate the ways in which judgements are made about the frequency of accidents and particular manoeuvres in various driving situations. For some groups a sorting task was interpolated between frequency judgement tasks, which required subjects to categorize driving errors either according to whether they were or were not dangerous, or did or did not commonly occur, in the contexts encountered earlier. Other groups did not have such interpolated tasks. The effects of the sorting exercise were to increase the subjective frequencies of accidents, but not subjective frequencies of particular manoeuvres in those same situations. These findings are discussed in terms of theories of heuristics and debiasing propounded by Fischoff, Kahneman, Tversky and others, and current research on drivers' assessments of risk and ability.

Knowledge base influences on judgments of frequency of occurrence

Chi and others have shown that a subject's knowledge base can have dramatic effects on cognitive tasks, sometimes reversing typical developmental differences. On the other hand, judgments of frequency-of-occurrence information have been shown to be immune to factors that typically affect memory. Kindergartners and adults judged frequency of well-known or unknown stimuli. Children were better able to judge frequency of occurrence of classmates than of famous adults (Experiment 1) or unknown children (Experiment 2). Similarly, adults were better able to judge frequency of occurrence of known adult faces than of unknown children (Experiment 1) or unknown adults (Experiment 3). The experiments reported here indicated that even an elementary process like frequency estimation is influenced by domain-specific knowledge of the stimuli.

Adult age comparisons in the processing of event frequency information.

The usual superiority in frequency-of-occurrence judgments of younger vs. older subjects was hypothesized to result from greater strategic encoding of the materials conveying frequency information. A subject-paced, visual search task was designed to control nontarget word encoding. Relative frequency judgments for the nontarget word pairs were equally accurate for younger and older subjects, and performance of both groups was above chance. Results suggest that strategic cover-task encoding can induce age differences in incidental frequency processing. Consistent with a nonoptimal as opposed to an optimal view, automatic processes require only minimal capacity for above-chance performance, but additional strategic resources can increase performance. When such additional resources are used more by younger than by older subjects, the former are better in frequency performance.

Illusory correlation and the maintenance of sex role stereotypes in children

The present work tested the hypothesis that children would perceive illusory correlations leading to greater recall of events that confirm rather than disconfirm sex-stereotypic beliefs. In the study, 33 second graders and 34 fourth graders were shown slides of adult males and females engaged in traditional sex role activities, nontraditional activities, and gender-neutral activities. Frequency judgments of the occurrence of each Stimulus Type x Stimulus Sex category served as the dependent measure. In actuality there was no correlation between gender and activity type in the stimulus set. As expected, both age groups perceived illusory correlations, giving the highest frequency estimates to traditional stimuli and the lowest frequency estimates to nontraditional stimuli. Individual differences in level of stereotyped attitudes had no effect on this cognitive bias. Results are discussed in terms of gender schema theory and the maintenance of sex role stereotypes.

Why are Amnesic Judgements of Recency and Frequency Made in a Qualitatively Different Way from those of Normal People?

The Huppert and Piercy (1978) test of recency and frequency judgements was given to a group of 12 non-Korsakoff amnesics of mixed aetiology and to four non-amnesic patients with selective frontal lobe lesions. The results confirmed that non-Korsakoff amnesics show a significant tendency to base their recency and frequency judgements on memory strength and that amnesics with medial temporal lobe damage show this tendency at least with recency judgements. The patients with frontal lobe lesions performed like normal subjects. Patients who were dysexecutive or impaired in cognitive resources were less likely to base recency judgements on trace strength. Such a recency bias was not however, correlated with measures of amnesic severity. The tendency to base frequency judgements on memory strength was not related to either degree of amnesia or reduction of cognitive resources.

Cognitive impairments in depression

Depressed patients perform poorly on memory tests. This may reflect a failure to employ encoding strategies that facilitate recall or a generalized inability to allocate cognitive effort to more difficult tasks. Inpatients with major depression or personality disorders and age- and IQ-matched normal controls were administered an automatic frequency of occurrence test and verbal paired associate recall and recognition memory tests. There was no difference in frequency judgments among the subject groups. Both depressed and personality disordered groups recalled and recognized fewer words than normal subjects, with the depressed subjects tending to recall and recognize the fewest words. There was a strong effect of task difficulty on memory performance but this effect was consistent across subject groups. These findings suggest that the poorer performance of depressed patients on memory tests reflect basic memory impairments rather than a general inability to allocate cognitive effort to more demanding tasks. However, these impairments may not be specific to depression but may reflect general effects of psychopathology on memory.

Memories of a bicycle tour

AbstractOne person's memories of a 47‐day bicycle tour of Scandinavia were tested 3–4 months later. The tests assessed frequency, spatial, and temporal knowledge of events. Results indicated that frequency judgements were based on some combination of counts of discrete event memories and a general impression of the tour. Episodic memories showed clear variation as a function of where events had occurred, and judged and actual locations of episodes were strongly related. In fact, knowledge of the week in which something had happened appeared to hinge on where in a sequence of locations it was thought to have taken place. The apparent dependence of temporal judgements on spatial information is consistent with other findings in the literature indicating that temporal memories about past events are derived from a variety of other associated information, much of which is temporally referenced.

Frequency judgments: The problem of defining a perceptual event.

In four experiments the conditions under which frequency judgments reflect the relative frequency of complex perceptual events were explored. Subjects viewed a series of 4 x 4 grids each containing seven items, which were letters and numbers in one of four typefaces. Later judgments of the relative frequency with which particular letters appeared in particular typefaces were unaffected by a warning about an upcoming frequency judgment task, but were affected by both the time available for processing the stimuli and the nature of the cover task subjects engaged in while viewing the grids. Frequency judgments were poor when exposure durations were less than 2 s and when the cover task directed subjects' attention merely to the locations of the items within the grids. Frequency judgments improved when the cover task directed subjects' attention to the identity of the stimuli, especially to the conjunction of letter and typeface. The results suggest that frequency estimation of complex stimuli may be possible only for stimuli that have been processed as phenomenal objects.

Judgments of Category Size: Now You Have Them, Now You Don't

To provide at least a partial explanation for the level-of-processing effect in frequency judgments, in three experiments we explored the role of covert elicitations of events on subsequent frequency judgments. Subjects were asked to judge the number of category instances that had been presented, when cued at retrieval by the category name. In these experiments we hoped to carry the argument regarding the importance of covert occurrences to its extreme. That is, we sought to show that in the absence of covert occurrences of the category label during encoding, judgments of category size would be impossible. Alternatively, when covert occurrences of those category labels were encouraged during encoding, frequency judgments would be possible. We were successful in two experiments, but only moderately successful in another.

Frequency judgments: The problem of defining a perceptual event.

Frequency judgments: The problem of defining a perceptual event.

Judgments of frequency of social stimuli: How schematic is person memory?

Judgments of frequency of social stimuli: How schematic is person memory?

Judgments of frequency of social stimuli: How schematic is person memory?

Judgments of frequency of social stimuli: How schematic is person memory?

A choice reaction time analysis of spatial frequency discrimination

Simple reaction time to the onset of sinewave gratings was measured as a function of spatial frequency in two observers. These results are compared to the choice reaction time required for the observer to correctly discriminate the spatial frequency of two gratings flashed sequentially. Grating contrast was either 0.75 or 1.5 logarithmic units above the detection threshold for each spatial frequency tested. The spatial phase and contrast of the reference and test gratings were varied from trial to trial by small random amounts to eliminate fixed cues other than the difference frequency. The spatial frequency difference between the reference and test grating was either 0.125, 0.25 or 0.5 octave. As has been earlier reported, simple reaction time increases with increasing spatial frequency. Contrary to this, choice reaction time first increases (up to 4c/deg) and then decreases. We derived the time required by the observer to make a spatial frequency judgement by subtracting the simple reaction time from the choice reaction time for a given spatial frequency and contrast. The maximum decision time occurs in the medium spatial frequency range (between 1 and 4 c/deg), at which frequencies we are most sensitive. The time required to make a correct spatial-frequency discrimination decreases with increasing spatial-frequency difference. The decision time is, however, fairly invariant over a large range of suprathreshold contrast levels. The findings suggest that the decision time for spatial frequency discrimination increases with the number of mechanisms involved.

Evaluating evidence for automaticity in frequency of occurrence judgments: a bias for bias?

Frequency of occurrence judgments were evaluated in young adults recovering from closed-head injuries, normal elderly, and young adult controls. Impaired performance was observed in both head-injured and elderly subjects, a result contrary to Hasher and Zacks' 1979 hypothesis that this information accumulates in memory via automatic processes which are unaffected by age, but supporting their conjecture that damage to the central nervous system would be sufficient to interfere with this function. The head-injured subject's performance on the frequency judgment task was correlated with effortful memory capacity as measured by several widely used memory tests. Whether the obtained group differences reflect differences in memory capacity or response criteria effects is discussed, and several methods of analyzing the data are compared.

Automatic and effortful processing after severe closed head injury

To investigate the automatic versus effortful distinction following severe closed head injury (CHI), we administered free recall and frequency of occurrence tasks to patients and controls. In Experiment 1 we found that both free recall (an effortful task) and judgment of relative frequency of occurrence (an automatic task) were impaired in 15 CHI patients as compared to 14 controls. In Experiment 2 we corroborated this finding and showed that absolute estimates of frequency were also impaired in new samples of 16 patients and 16 controls. We infer that cognitive tasks which normal individuals can perform without practice, feedback, or instructions may demand more effortful strategies following severe CHI.

Frequency Judgments in an Auditing-Related Task

The topic of frequency judgments is important to auditors because practically all auditing judgments use frequency data as one of the inputs in the decision-making process. For example, frequency judgments based on actual audit experience with a given company become part of audit planning on repeat engagements. In addition to the actual audit hours used in an area, the frequency of errors discovered in past audits may serve as a guide in allocating hours in the current audit plan. This possibility is supported by Kinney's [1979] results that adjustments made in prior years' audits were relatively accurate predictors of the current year's errors. Similarly, in evaluating internal controls, the auditor's judgments of the frequency with which different accounting processes generate errors should affect evaluations of the importance of control weaknesses discovered in the system. Libby, Artman, and Willingham [1985] found that the frequency with which subprocesses generate errors had a major impact on control risk assessments. The importance of frequency judgments was also demonstrated by Libby [1985], who showed that auditors rely on their judgments of frequency of occurrence of financial statement errors when generating hypotheses in an analytical review task.

Frequency and recognition judgement by young and elderly adults

The aim of this study was to compare the performance of young and elderly subjects at two different memory tasks (frequency judgement and word recognition) under two retrieval conditions (forced and unforced choice) in order to determine the source of any incidental age-related memory deficit. Fifty young subjects (aged from 15 to 35 yr) and 50 elderly subjects (aged from 60 to 85) participated in this study. The results showed a significant difference between age groups at word recognition independent of retrieval condition, while frequency judgement was found significantly impaired in elderly as compared with young subjects only when an unforced choice procedure was required. It is suggested that age related memory impairment is not dependent on the nature of the task, but rather to the amount of retrieval information which is given to the subjects.

Judgments of frequency and recognition memory in a multiple-trace memory model.

Judgments of frequency and recognition memory in a multiple-trace memory model.

Judgments of frequency and recognition memory in a multiple-trace memory model.

Judgments of frequency and recognition memory in a multiple-trace memory model.

Generation effects in frequency judgment.

Generation effects in frequency judgment.