Tests of measurement invariance failed to support the application of the "then-test"

Objective
The use of then-test (retrospective pre-test) scores has frequently been proposed as a solution to potential confounding of change scores because of response shift, as it is assumed that then-test and post-test responses are provided from the same perspective. However, this assumption has not been formally tested using robust quantitative methods. The aim of this study was to compare the psychometric performance of then-test/post-test with traditional pre-test/post-test data and assessing whether the resulting data structures support the application of the then-test for evaluations of chronic disease self-management interventions.

Study Design and Setting
Pre-test, post-test, and then-test data were collected from 314 participants of self-management courses using the Health Education Impact Questionnaire (heiQ). The derived change scores (pre-test/post-test; then-test/post-test) were examined for their psychometric performance using tests of measurement invariance.

Results
Few questionnaire items were noninvariant across pre-test/post-test, with four items identified and requiring removal to enable an unbiased comparison of factor means. In contrast, 12 items were identified and required removal in then-test/post-test data to avoid biased change score estimates.

Conclusion
Traditional pre-test/post-test data appear to be robust with little indication of response shift. In contrast, the weaker psychometric performance of then-test/post-test data suggests psychometric flaws that may be the result of implicit theory of change, social desirability, and recall bias.

Size invariance of fibrous networks of supramolecular soft materials during formation under critical volume confinement

The rheological properties of a hierarchically structured supramolecular soft material are mainly determined by the structure of its network. Controlling the thermodynamic driving force of physical gels (one type of such materials) during the formation has proven effective in manipulating the network structure due to the nature of nucleation and growth of the fiber network formation in such a supramolecular soft material. Nevertheless, it is shown in this study that such a property can be dramatically influenced when the volume of the system is reduced to below a threshold value. Unlike un-confined systems, the network structure of such a soft material formed under volume confinement contains a constant network size, independent of the experimental conditions, i.e. temperature and solute concentration. This implies that the size of the fiber networks in such a material is invariable and free from the influence of external factors, once the volume is reduced to a threshold. The observations of this work are significant in the control of the formation of fibrous networks in materials of this type.

Achieving illumination invariance using image filters

In this chapter we described a novel framework for automatic face recognition in the presence of varying illumination, primarily applicable to matching face sets or sequences. The framework is based on simple image processing filters that compete with unprocessed greyscale input to yield a single matching score between individuals. By performing all numerically consuming computation offline, our method both (i) retains the matching efficiency of simple image filters, but (ii) with a greatly increased robustness, as all online processing is performed in closed-form. Evaluated on a large, real-world data corpus, the proposed framework was shown to be successful in video-based recognition across a wide range of illumination, pose and face motion pattern changes

A new look at filtering techniques for illumination invariance in automatic face recognition

Illumination invariance remains the most researched, yet the most challenging aspect of automatic face recognition. In this paper we propose a novel, general recognition framework for efficient matching of individual face images, sets or sequences. The framework is based on simple image processing filters that compete with unprocessed greyscale input to yield a single matching score between individuals. It is shown how the discrepancy between illumination conditions between novel input and the training data set can be estimated and used to weigh the contribution of two competing representations. We describe an extensive empirical evaluation of the proposed method on 171 individuals and over 1300 video sequences with extreme illumination, pose and head motion variation. On this challenging data set our algorithm consistently demonstrated a dramatic performance improvement over traditional filtering approaches. We demonstrate a reduction of 50-75% in recognition error rates, the best performing method-filter combination correctly recognizing 96% of the individuals.

Measurement invariance across chronic conditions: a systematic review and an empirical investigation of the Health Education Impact Questionnaire (heiQ™).

To examine whether lack of measurement invariance (MI) influences mean comparisons among different disease groups, this paper provides (1) a systematic review of MI in generic constructs across chronic conditions and (2) an empirical analysis of MI in the Health Education Impact Questionnaire (heiQ™).

Factor structure and measurement invariance of the Health Education Impact Questionnaire: does the subjectivity of the response perspective threaten the contextual validity of inferences?

Objective:
On-going evidence is required to support the validity of inferences about change and group differences in the
evaluation of health programs, particularly when self-report scales requiring substantial subjectivity in response generation are used as outcome measures. Following this reasoning, the aim of this study was to replicate the factor structure and investigate the measurement invariance of the latest version of the Health Education Impact Questionnaire, a widely used health program evaluation measure.
Methods:
An archived dataset of responses to the most recent version of the English-language Health Education Impact
Questionnaire that uses four rather than six response options (N=3221) was analysed using exploratory structural equation
modelling and confirmatory factor analysis appropriate for ordered categorical data. Metric and scalar invariance were
studied following recent recommendations in the literature to apply fully invariant unconditional models with minimum
constraints necessary for model identification.
Results:
The original eight-factor structure was replicated and all but one of the scales (Self Monitoring and Insight) was
found to consist of unifactorial items with reliability of ⩾0.8 and satisfactory discriminant validity. Configural, metric and scalar
invariance were established across pre-test to post-test and population sub-groups (sex, age, education, ethnic background).
Conclusion:
The results support the high level of interest in the Health Education Impact Questionnaire, particularly for use as a pre-test/post-test measure in experimental studies, other pre–post evaluation designs and system-level monitoring and evaluation.

Measurement invariance of English and French Health Education Impact Questionnaire (heiQ) empowerment scales validated for cancer

PURPOSE: If measurement invariance (MI) is demonstrated for a scale completed by respondents from two different language groups, it means that the scale measures the same construct in the same way in both groups. We assessed MI of the French- and English-language versions of the five Health Education Impact Questionnaire (heiQ) empowerment scales validated for the cancer setting. METHODS: Data came from two cross-sectional studies of Canadian cancer survivors (704 English, 520 French). Single-group confirmatory factor analysis (CFA) was used to test whether the hypothesized factor structure of the French-language heiQ empowerment scales fit the data. Multi-group CFAs were conducted to assess different levels of MI conditions (configural, metric, scalar, strict, as well as MI of factor variances, covariances, and latent means) of the French- and English-language heiQ empowerment scales. RESULTS: The correlated five-factor model showed good fit in both language groups (goodness-of-fit indices: CFI ≥ .97; RMSEA ≤ .07). Goodness-of-fit indices and tests of differences in fit between models supported MI of the five-factor model across the two language groups (∆CFI ≤ -.010 combined with ∆RMSEA ≤ .015). CONCLUSIONS: The French- and English-language heiQ empowerment scales measure the same five dimensions of empowerment in the same way across both language groups. Thus, any observed similarities or differences between French- and English-speaking respondents completing these scales are valid and reflect similarities or differences in empowerment across language groups, not measurement artifact. Consequently, heiQ empowerment data from English- and French-speaking respondents can be directly pooled or contrasted in data analyses.

Factorial invariance of the DASS-21 among adolescents in four countries

The use of scales to measure constructs in populations or contexts other than that in which they were established is highly controversial. Despite this, the use of scales without reference to "local" psychometric data is still widespread. In this study we examined the factor structure of the short 21-item form of the Depression, Anxiety, and Stress Scales (DASS-21), when it was applied to adolescent samples recruited from high schools in Australia (N = 371), Chile (N = 448), China (N = 558), and Malaysia (N = 388). Multigroup confirmatory factor analyses revealed that the purported three-factor structure of the DASS-21 was supported in each location with structural invariance across locations. While convergent and divergent validity studies are required to support this finding, the DASS-21 appears to be suitable for use with adolescents in these locations.

Self-perceived distress and impairment in problem gamblers: a study of pre- to post-treatment measurement invariance

Gambling help services typically evaluate treatment outcomes using self-reported responses and measurements. However, gamblers’ conceptualisations and prioritisations with respect to these measurements may shift over time. Thus, changes in the self-reported responses may not always reflect true change in the individuals. This study investigated for response shift in self-report measures of psychological distress and impairment in 293 help-seeking problem gamblers. We used confirmatory factor analysis to model data structures from pre-treatment to post-treatment. The findings indicated that a response shift had occurred. Two items became less important and one item became more important in measuring psychological distress. Measurement invariance was achieved for the complete set of items for impairment. These findings provide a more in-depth understanding of the nature of self-report outcomes in otherwise routinely collected data.

Self-perceived distress and impairment in problem gamblers : a study of pre- to post-treatment measurement invariance

Gambling help services typically evaluate treatment outcomes using self-reported responses and measurements. However, gamblers’ conceptualisations and prioritisations with respect to these measurements may shift over time. Thus, changes in the self-reported responses may not always reflect true change in the individuals. This study investigated for response shift in self-report measures of psychological distress and impairment in 293 help-seeking problem gamblers. We used confirmatory factor analysis to model data structures from pre-treatment to post-treatment. The findings indicated that a response shift had occurred. Two items became less important and one item became more important in measuring psychological distress. Measurement invariance was achieved for the complete set of items for impairment. These findings provide a more in-depth understanding of the nature of self-report outcomes in otherwise routinely collected data.

Polyhedral : recycling boundary ecologies

Foregrounding the extent to which 'place' remains resistant to the politics and poetics of 'network culture', this essay approaches place as a boundary ecology rather than as an instance of cultural invariance. It calls on readers to think about attempts to actively recycle cultural 'debris' or 'waste' through an ethics of passage instead of the kind of instrumentalist statics that prevents the development of an ontology of mobility. Con-tending that such a capacity to inhabit passage is compromised by the eschatological language used to communicate the implications of environmental disaster, as well as by languages of consultation that (con-ceptually) empty place of any creative power to incubate alternatives – events, modes of relation –, the essay stresses the mythopoetic techniques that produce places as knots or nodal points within a network of pas-sage. The designer's task is to create the hinge mechanisms that render such boundary ecologies inhabitable imaginatively, and by materialising the nexus between creativity and change to alter our position vis-a-vis our ethical responsibilities as citizens of a shared biosphere.

Semi-hyperbolic mappings in Banach spaces

The definition of semi-hyperbolic dynamical systems generated by Lipschitz continuous and not necessarily invertible mappings in Banach spaces is presented in this thesis. Like hyperbolic mappings, they involve a splitting into stable and unstable spaces, but a slight leakage from the strict invariance of the spaces is possible and the unstable subspaces are assumed to be finite dimensional. Bi-shadowing is a combination of the concepts of shadowing and inverse shadowing and is usually used to compare pseudo-trajectories calculated by a computer with the true trajectories. In this thesis, the concept of bi-shadowing in a Banach space is defined and proved for semi-hyperbolic dynamical systems generated by Lipschitz mappings. As an application to the concept of bishadowing, linear delay differential equations are shown to be bi-shadowing with respect to pseudo-trajectories generated by nonlinear small perturbations of the linear delay equation. This shows robustness of solutions of the linear delay equation with respect to small nonlinear perturbations. Complicated dynamical behaviour is often a consequence of the expansivity of a dynamical system. Semi-hyperbolic dynamical systems generated by Lipschitz mappings on a Banach space are shown to be exponentially expansive, and explicit rates of expansion are determined. The result is applied to a nonsmooth noninvertible system generated by delay differential equation. It is shown that semi-hyperbolic mappings are locally φ-contracting, where -0 is the Hausdorff measure of noncompactness, and that a linear operator is semi-hyperbolic if and only if it is φ-contracting and has no spectral values on the unit circle. The definition of φ-bi-shadowing is given and it is shown that semi-hyperbolic mappings in Banach spaces are φ-bi-shadowing with respect to locally condensing continuous comparison mappings. The result is applied to linear delay differential equations of neutral type with nonsmooth perturbations. Finally, it is shown that a small delay perturbation of an ordinary differential equation with a homoclinic trajectory is ‘chaotic’.

Constructing the monster : notions of the monstrous in classical antiquity

Focussing on humaniod monsters, this thesis uses insights from Foucault's theory about the "archaeology" of discourses and Derrida's practice of deconstruction to examine how monstrosity was spoken of in antiquity, and how the various "sciences" dealt with anomalous monsters without jeopardising their epistemological credibility. Discussion begins with a survey of the semantic field of teras and monstrum. Since portentousness was central to both terms, the signification of monstrous portents in divinatory practice is next aalysed in the historiography of Herodotus, Livy, and others. Cicero's De divinatione reveals the theory and the problem for that science posed by accidental monstrosities. Chance and novelty are also issues in mythical and scientific cosmogonies < of Hesiod, and Orphism, Empedo-cles, and Lucretius> , where monsters arise and are dealt with while cosmic regularities, reproductive and ethical, are being established. Teleology and the stability of species'forms emerge as important concerns. These issues are further considered in Aristotle's bioogy and in medical writings from Hippocrates to Galen. There, theories are produced about monstrous embryology which attempt to answer the question of how deformities occur if species' forms are perpetuated through repro-duction. Biological and taxonomic--as well as ethical--boundaries are violated also by mythic human-beast hybrids. Narratives about such anomalies clarify the nature of monstrous deviance and enact solutions to the problem. Their strategies have much in common with other modes of discourse. Ethnography is posed similar questions about monstrous races' physical and ethical deviations from the civilised norm; it speaks of those issues in terms of invariance of form through generations, geographical remoteness and the codes which situate those races ethically. Finally, Augustine’s discourse on monstrous individuals and races is examined as Christianity’s belief in God’s governance reformulates the ancient’s discussions of chane or novelty and the invariance of species. In all these discourses founded on determinate meaning, the persistant paradox of monstrosity need offer no challenge to rationality provided its indefinable diversity is unacknowledged and the notion is constructed in such a way as to reaffirm the certainties.

A simple two-axiom characterization of the Nash solution

The oldest and best-known cooperative bargaining solution concept is the Nash solution. Nash [2] characterized his seminal solution concept by using the axioms of ‘Independence of Irrelevant Alternatives’ (IIA), ‘Weak Pareto Optimality’ (WPO), ‘Symmetry’ (SYM), and ‘Scale Invariance’ (SI). Except for WPO, these axioms have been at the center of controversy (especially the most crucial axiom, IIA). This paper considers a new and simple axiom ‘Focal Relevance of a Pareto-optimal Midpoint’ (FRPM). It turns out that the Nash solution can be characterized by WPO and FRPM only.

Determinants of visual size constancy in different orientations in light and darkness

This project was concerned with the perception of size constancy of simple, elongated and planar objects in the light and dark. The main findings are: transverse, vertical and medial axes give rise to different degrees of size constancy; true size and shape of the objects proved to be a factor in size constancy; the size-distance invariance hypothesis (SDIH) cannot explain underconstancy in the light, and perfect constancy in the dark.