Denoting the base-free measure of change

Bond criticized the base-free measure of change proposed by Tucker, Damarin, and Messick by pointing to an incorrect derivation which is here viewed instead as a correct derivation entailing an inadequately specified tacit assumption. Bond's revision leads to estimates of the correlation between initial position and change which are negatively biased by correlated errors, whereas the original approach, with the tacit assumption properly denoted, leads to unbiased values.     

On the base-free measure of change proposed by Tucker,Damarin and Messick

Tucker, Damarin and Messick proposed a base-free measure of change which involves the computation of residual scores that are uncorrelated with true scores on the pretest. The present note discusses this change measure and demonstrates that, because of an incorrect derivation by the authors, properties they attribute to (the coefficient for the regression of true scores from the second testing on true scores from the first testing) are, in fact, properties ofb, the ordinary regression coefficient. A correct derivation of the initial position—change correlation in terms of is obtained, and Tucker et al.'s discussion of the law of initial values is reconsidered.The preparation of this paper was supported by the Learning Research and Development Center supported in part as a research and development center by funds from the National Institute of Education.     

The relative error magnitude in three measures of change

Formulas for the standard error of measurement of three measures of change—simple difference scores, residualized difference scores, and the measure introduced by Tucker, Damarin, and Messick—are derived. Equating these formulas by pairs yields additional explicit formulas which provide a practical guide for determining the relative error of the three measures in any pretest-posttest design. The functional relationship between the standard error of measurement and the correlation between pretest and posttest observed scores remains essentially the same for each of the three measures despite variations in other test parameters (reliability coefficients, standard deviations), even when pretest and posttest errors of measurement are correlated.     

Analysing cycling as a social practice: An empirical grounding for behaviour change

Despite significant national and local efforts over the last decade to stimulate uptake of cycling in the UK, levels of cycling (particularly utility cycling) remain at around 2% of journeys. Understanding of cycling behaviour and subsequent development of interventions has typically been undertaken using an individualist approach, often relying on psychologically based models of behaviour. This paper argues that Social Practice Theory (SPT) may be a valuable addition to practitioner’s toolboxes by providing an alternative means of understanding the complex dynamics between the elements that constitute the practice of utility cycling, allowing it to be considered as a social issue, rather than focusing solely on individual behaviour. This is demonstrated within the paper by the use of SPT to reanalyse quantitative and qualitative datasets that explore views and experiences of both cyclists and non-cyclists. Therein, the practice of utility cycling is described according to its three elements; materials, meaning and competences and the potential benefits of this approach are discussed; particularly its ideological shift away from ‘victim blaming’ and its natural support of interdisciplinary intervention design.     

On the identification of clinically significant client changes: Reinterpretation of Jacobson's cut scores

Cut points or cut scores play a central role in Jacobson's popular method of identifying clinically significant changes in psychotherapy. When pre- and posttherapy scores of a client are on different sides of one of these cut scores, the change is considered clinically significant, provided that it is also reliable (i.e., not due to measurement errors). This article critically examines the meanings and implications of these cut scores. Contrary to popular beliefs, they are generallynot the test scores for which the probability of belonging to the Functional population is equal to the probability of belonging to the Dysfunctional population. When the Functional population distribution is above that of the Dysfunctional population, persons scoring above these cut scores can, in fact, have much greater probabilities of belonging to the Dysfunctional than to the Functional population. Goals of Jacobson's method can be attained only with Bayesian methods. Bayesian modifications of Jacobson's cut scores are proposed, although their use is limited by the availability of relevant base rates. Bayesian methods (a) can provide information about the probability that an individual belongs to each population, given his (her) score, and (b) are expected to yield total misdiagnosis rates that are many times lower than those of Jacobson's method. Users of Jacobson's method are cautioned against interpreting ratios of likelihoods as if they were ratios of posterior probabilities.     

Problem decomposability as a factor in complexity of the dimensional change card sort task

According to cognitive complexity and control (CCC) theory complexity depends on number of levels of a hierarchy of rules. According to relational complexity (RC) theory complexity is a function of the number of related variables in the task, and the most difficult tasks are those in which there is a constraint on decomposition into simpler subtasks. One hundred and twenty, 3–6-year old children were tested on the standard dimensional change card sort (DCCS) task, or a modified version, the DecompDCCS, in which the dimensions could be decomposed into subtasks. The standard version requires two levels of a hierarchy to be processed, and is ternary relational according to RC theory, whereas the subtasks of the DecompDCCS are binary relational. The DecompDCCS was easier than the DCCS for 3–4 year-olds, but all 5–6 year-olds succeeded on both. The results indicate that decomposability into simpler subtasks, as suggested by RC theory, is a factor in difficulty of DCCS. The role of decomposability in other tasks that are persistently difficult for young children is discussed.     

The importance of children's illness beliefs: the Children's Illness Perception Questionnaire (CIPQ) as a reliable assessment tool for eczema and asthma

A lack of information about disease in children can lead to erroneous views such as children believing that hospital admittance or the presence of a disease is a punishment for a perceived wrong. There has thus far been no standard tool available to measure children's illness conceptualizations from a Leventhalian framework. Three groups of children with eczema, asthma and eczema and asthma between the ages of 7 and 12 years of age were recruited. Children were given the Children's Illness Perception Questionnaire (CIPQ), a 26-item instrument adapted from the Illness Perception Questionnaire for adults. A Kuder - Richardson 20 test of reliability for dichotomous data was performed allowing an estimate of the internal consistency of the measurement scales. It can be seen that, for all three illness groups, internal consistency is acceptable for the timeline and consequences scale. The cure/control scale, however, was not internally consistent for any illness group. As health professionals, we need to develop the means to further understand how paediatric illness beliefs relate to specific disease types, age and psychosocial factors and the utility of this instrument is discussed within this context.     

Using the longitudinal Guttman simplex as a basis for measuring growth

Many difficulties inherent in the measurement of growth stem from the use of traditional measurement methodologies. The longitudinal Guttman simplex (LGS), an alternative approach based on a model of growth, is discussed in this article. The LGS has several advantages over traditional methodology. First, interindividual differences in developmental rates are a part of the model. Second, the LGS procedure can easily handle any number of occasions of measurement. Third, the LGS is suited to nonlinear as well as linear monotonic growth. Fourth, a consistency index associated with the LGS methodology, CL, indicates the extent to which cumulative, unitary development characterizes a particular latent variable. Finally, and perhaps most important, because a model of the growth undergone by the latent variable being measured is incorporated in the LGS model the resulting instruments enjoy a high level of construct validity. The LGS is limited to cumulative, unitary development; additional measurement theories are needed for other kinds of development.     

Grammatical properties of sentences as a basis for concept formation

A concept-formation study was run using sets of sentences in eight different syntactic patterns as target categories. These were based on all possible combinations of voice (active or passive), mood (declarative or interrogative), and modality (affirmative or negative). Subjects were 32 senior high school students who participated as volunteers in the computer-controlled experiment. Subjects were able to categorize sentences based solely on sentence types rather than semantic content, but an analysis of the errors committed in the course of learning showed that it was the semantic significance of different types rather than pattern differences as such to which a subject responded. The implications of this for grammatical formulations and the interpretation of psychological research were discussed.     

Mechanisms of change in cognitive behavioral therapy for panic disorder: The unique effects of self-efficacy and anxiety sensitivity

The present study examined temporal dependencies of change of panic symptoms and two promising mechanisms of change (self-efficacy and anxiety sensitivity) during an 11-session course of cognitive-behavior therapy (CBT) for Panic Disorder (PD). 361 individuals with a principal diagnosis of PD completed measures of self-efficacy, anxiety sensitivity, and PD symptoms at each session during treatment. Effect size analyses indicated that the greatest changes in anxiety sensitivity occurred early in treatment, whereas the greatest changes in self-efficacy occurred later in treatment. Results of parallel process latent growth curve models indicated that changes in self-efficacy and anxiety sensitivity across treatment uniquely predicted changes in PD symptoms. Bivariate and multivariate latent difference score models indicated, as expected, that changes in anxiety sensitivity and self-efficacy temporally preceded changes in panic symptoms, and that intraindividual changes in anxiety sensitivity and self-efficacy independently predicted subsequent intraindividual changes in panic symptoms. These results provide strong evidence that changes in self-efficacy and anxiety sensitivity during CBT influence subsequent changes in panic symptoms, and that self-efficacy and anxiety sensitivity may therefore be two distinct mechanisms of change of CBT for PD that have their greatest impact at different stages of treatment.     

Inadequacy of recall as a basis for frequency knowledge.

Subjects studied a word list comprising varying numbers of words from distinct semantic categories. The category names (trees, colors, etc.) were then re-presented, and for each name subjects either recalled as many exemplars as they could or estimated how many had been included in the list (Experiments 1 and 2). Recall was not sufficiently informative about actual category sizes to account for performance in the frequency estimation task. Moreover, it remained insufficiently informative when efforts were made to induce a recall-estimate strategy by requiring overt recall prior to estimation (Experiments 3-5), by using very small categories (Experiment 4), and by not showing the category name at study (Experiment 5), even though it did allow a partial account of estimation when the category exemplars were individually cued (Experiment 6). It is concluded that the role of recall in frequency estimation is much exaggerated.