The corneal reflection technique and the visual preference method: sources of error.

Corneal reflection techniques for eye fixation position measurement have been used in recent years to assess such variables of visual behavior as duration of looking and the area(s) of the stimulus fixated. These techniques are especially useful when measuring visual regard in infants and young children as head restraints are not required. In an earlier article the present authors demonstrated, empirically, that the common assumption that the center of the pupil represents the line of sight is untenable. The present article considers the causes of the errors present in these techniques: it can be shown that theoretical calculations of these sources of error, calculations based both on the anatomy of the eye, and on the optics involved, produce good agreement with their empirically derived magnitudes.     

Children's sensitivity to error magnitude when evaluating informants

Three experiments examined children's (N = 80; 40; 48) sensitivity to error magnitude as a measure of informants’ past accuracy, and indication of future reliability. Experiments 1 and 2 assessed whether, in a forced-choice task, children would evaluate as better and show greater trust in an informant whose previous errors were consistently within close range of the correct answer than one whose errors were more extreme. Six-to-seven-year olds displayed such sensitivity in an animal-labeling context (Experiment 1), whereas 4–5-year olds did so only in a number context, where the magnitude of errors was more obviously quantifiable (Experiment 2). Given a free choice in Experiment 3, 6- and 7-year olds preferred to guess the answers themselves rather than accept the claims of either informant. Only the older children's guesses, however, were informed by the testimony of the previously closer informant, indicating an increased awareness that this informant's claims could guide them toward the correct answers.     

Fitting cross-classification table data to models when observations are subject to classification error

Individuals are classified in a cross-classification table where two behavioral observations on each individual determine the classification. The problem is to test certain structural models assumed to underlie the cross-classified observations. A minimum chi-square test procedure is proposed.     

Inserting mastered targets during error correction when teaching skills to children with autism

Research has identified a variety of effective approaches for responding to errors during discrete‐trial training. In one commonly used method, the therapist delivers a prompt contingent on the occurrence of an incorrect response and then re‐presents the trial so that the learner has an opportunity to perform the correct response independently. Some authors recommend inserting trials with previously mastered targets between the prompted response and opportunities to respond independently, but no studies have directly examined the benefits of this approach. In this study, we manipulated the placement of trials with mastered targets during discrete‐trial training to compare the effectiveness of error correction with and without this recommended insertion procedure. Four children with autism participated, and each was taught 18 targets across 3 target sets. Results indicated that embedding trials with mastered targets into error correction may not confer benefits for most children and that doing so may lead to less efficient instruction.     

Measuring discriminability when there are multiple sources of bias

Performance measures such as log d and d′?aim to measure stimulus discriminability independently of response bias in conditional discrimination tasks, including the yes/no signal-detection procedure. However, they assume only one dimension of bias (e.g., response color) and do not account for bias on additional dimensions (e.g., response side). Such bias reduces log d, thus violating the statistical independence of discriminability and bias measurements. We modified log d to account for side bias and reanalyzed previous side-biased data. With strong side bias, the modified log d differed enough from the standard log d to potentially alter the conclusions of an experiment. Simulations showed that the modified log d produces discriminability estimates that are more accurate and bias-independent than the standard log d calculation.     

Avoiding the dangers of averaging across subjects when using multidimensional scaling

Ashby, Maddox and Lee (Psychological Science, 5 (3) 144) argue that it can be inappropriate to fit multidimensional scaling (MDS) models to similarity or dissimilarity data that have been averaged across subjects. They demonstrate that the averaging process tends to make dissimilarity data more amenable to metric representations, and conduct a simulation study showing that noisy data generated using one distance metric, when averaged, may be better fit using a different distance metric. This paper argues that a Bayesian measure of MDS models has the potential to address these difficulties, because it takes into account data-fit, the number of dimensions used by an MDS representation, and the precision of the data. A method of analysis based on the Bayesian measure is demonstrated through two simulation studies with accompanying theoretical analysis. In the first study, it is shown that the Bayesian analysis rejects those MDS models showing better fit to averaged data using the incorrect distance metric, while accepting those that use the correct metric. In the second study, different groups of simulated ‘subjects’ are assumed to use different underlying configurations. In this case, the Bayesian analysis rejects MDS representations where a significant proportion of subjects use different configurations, or when their dissimilarity judgments contain significant amounts of noise. It is concluded that the Bayesian analysis provides a simple and principled means for systematically accepting and rejecting MDS models derived from averaged data.     

Complex movement patterns: Learning retention and sources of error in recall

In this study of kinaesthesis, the learning, retention, and recall of complex patterns was examined. Subjects were blindfolded, held a stylus in the right hand, and moved around stencil patterns, either actively or passively. The patterns were recalled with a free active movement of the right hand, after various amounts of practice, immediately or after a 60-s interval, once or twice in succession, with and without visual guidance. The shape and size of the drawings was compared with the criterion patterns. The effect of practice varied depending on whether the criterion movement was active or passive, and on the measure of recall performance. Even when the criterion patterns were freely practised, the recall traces showed large errors in shape and systematic shrinkage in size, and there were large individual differences. Regardless of these errors, recall performance was reliable. The effect of an unfilled retention interval varied as a function of practice. When the patterns were recalled under visual guidance, there was no shrinkage in the size of the drawings.     

The error power spectrum as a technique for assessing the performance of the human operator in a simple task

The measurement of performance of a human operator in a closed loop control system is considered; it is suggested that the power spectrum of the fluctuations of his tracking error (or error spectral density curve) gives a useful picture of performance and the equipment and technique for producing such a curve is described briefly.

As an example of the technique the power spectra obtained on several subjects performing a simple task with a pressure joystick are given and the implications of the shape of the curve are discussed.     

Minimizing error in measurement of error: a proposed method for calculation of error in a two-dimensional motor task

Traditional one-dimensional error scores are still consistently used in research on motor learning to quantify two-dimensional error; however, the inherent differences in two-dimensional tasks render that application inappropriate and often misleading. Consequently, the purpose of this paper was to propose a novel method of presenting errors, which more precisely represents the accuracy, direction, and variability of error in two-dimensional settings. Although closely related to several alternatives for representing errors, the methodology used and the results obtained provide a more accurate procedure for pinpointing critical trends in what have been commonly referred to as AE (absolute error), VE (variable error), CE (constant error), and E (total variability). The proposed measurements of AVE (adjusted variable error), DE (directional error), TSE (total spread of error), and RE (radial error) provide composite error scores carrying a variety of information about performance on two-dimensional tasks. Formulas and examples are provided to facilitate computation and enhance understanding of the proposed scores.     

TEMPEST in a gallimaufry: applying multilevel systems theory to person-in-context research

Terminological ambiguity and inattention to personal and contextual multilevel systems undermine personality, self, and identity theories. Hierarchical and heterarchical systems theories are used to describe contents and processes existing within and across three interrelated multilevel systems: levels of organization, representation, and integration. Materially nested levels of organization are used to distinguish persons from contexts and personal from social identity. Functionally nested levels of representation are used to distinguish personal identity from the sense of identity and symbolic (belief) from iconic (schema) systems. Levels of integration are hypothesized to unfold separately but interdependently across levels of representation. Multilevel system configurations clarify alternative conceptualizations of traits and contextualized identity. Methodological implications for measurement and analysis (e.g., integrating variable- and pattern-centered methods) are briefly described.     

Exploring experiences of children in applying a school-based mindfulness programme to their lives

Evidence for the effectiveness of mindfulness-based interventions for children and young people’s well-being is growing, particularly within educational settings. To date, very few studies have explored how children experience and apply mindfulness. This qualitative study investigated how children who received long-term mindfulness training applied mindfulness to their everyday lives. Year 6 Children (average age 11) were interviewed in three focus groups with their peers, in a semi-structured format, and the data was analysed using an inductive thematic analysis. The findings indicated that the children described mindfulness as assisting with their emotion regulation. Four themes were identified: (1) processes of emotion regulation (2) dysregulation prompt to apply mindfulness (3) challenges and strategies and (4) the conditions that support or hinder mindfulness use. These findings are discussed in the context of theories and evidence on emotion regulation, attachment, and mechanisms of mindfulness. Implications of these findings for future research of meditation-based approaches in schools, for example, self-compassion and kindness practices, are considered.     

Clarifying problems and offering solutions for correlated error when assessing the validity of selected-subtest short forms

The correlation between a short-form (SF) test and its full-scale (FS) counterpart is a mainstay in the evaluation of SF validity. However, in correcting for overlapping error variance in this measure, investigators have overattenuated the validity coefficient through an intuitive misapplication of P. Levy's (1967) formula. The authors of the present article clarify that such corrections should be based on subtest-level versus FS-level data. Additionally, the authors propose a simple, modified equation incorporating FS-level scores that provides liberal and conservative validity measures for comparison across estimation methods, and they demonstrate its use in both a normative (N = 2,450) and clinical psychiatric (N = 216) sample.     

Using "Bubbles" with babies: a new technique for investigating the informational basis of infant perception

The 'Bubbles' technique (Gosselin, F. & Schyns, P.G. (2001). Bubbles: A technique to reveal the use of information in recognition tasks. Vision Research, 41, 2261-2271) has been widely used to reveal the information adults use to make perceptual categorizations. We present, for the first time, an adapted form of Bubbles, suitable for use with young infants.     

Failure to obtain positive contrast when pigeons press a bar

In Experiment 1, two groups of pigeons were exposed to multiple variable-interval 1-min variable-interval 1-min schedules of reinforcement. The required response was a key peck for one group, and a foot press of a bar for the other. When the procedure was shifted to multiple variable-interval 1-min extinction, positive contrast occurred with pigeons that key pecked, whereas negative induction occurred with those that bar pressed. Moreover, the absence of contrast could not be ascribed to the lack of inhibition, since negative generalization gradients after bar press training were U-shaped in Experiment 2. The results are discussed in terms of possible relationships between positive contrast and the phenomenon of autoshaping.