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Book part
Publication date: 22 May 2013

LeAnne D. Johnson and Kristen L. McMaster

The contemporary focus on high fidelity implementation of research-based practices often creates tensions for educators who seek to balance fidelity with needed…

Abstract

The contemporary focus on high fidelity implementation of research-based practices often creates tensions for educators who seek to balance fidelity with needed flexibility as they strive to improve learner outcomes. In an effort to improve how decisions are made such that flexibility is achieved while fidelity to core components is maintained, this chapter begins with a discussion of the role of fidelity in research and practice. Particular attention is given to current conceptualizations of fidelity that may help inform theoretically and empirically driven adaptations to research-based practices. Specifically, we describe adaptations based on the instructional context for implementation and the characteristics of the individual learners. A framework for adapting research-based practices is then presented with relevant examples from research designed to optimize learner responsiveness without sacrificing fidelity to core components. The chapter ends with implications and future directions for research and practice.

Details

Evidence-Based Practices
Type: Book
ISBN: 978-1-78190-429-9

Article
Publication date: 29 March 2022

Mushi Li, Zhao Liu, Li Huang and Ping Zhu

Compared with the low-fidelity model, the high-fidelity model has both the advantage of high accuracy, and the disadvantage of low efficiency and high cost. A series of…

Abstract

Purpose

Compared with the low-fidelity model, the high-fidelity model has both the advantage of high accuracy, and the disadvantage of low efficiency and high cost. A series of multi-fidelity surrogate modelling method were developed to give full play to the respective advantages of both low-fidelity and high-fidelity models. However, most multi-fidelity surrogate modelling methods are sensitive to the amount of high-fidelity data. The purpose of this paper is to propose a multi fidelity surrogate modelling method whose accuracy is less dependent on the amount of high-fidelity data.

Design/methodology/approach

A multi-fidelity surrogate modelling method based on neural networks was proposed in this paper, which utilizes transfer learning ideas to explore the correlation between different fidelity datasets. A low-fidelity neural network was built by using a sufficient amount of low-fidelity data, which was then finetuned by a very small amount of HF data to obtain a multi-fidelity neural network based on this correlation.

Findings

Numerical examples were used in this paper, which proved the validity of the proposed method, and the influence of neural network hyper-parameters on the prediction accuracy of the multi-fidelity model was discussed.

Originality/value

Through the comparison with existing methods, case study shows that when the number of high-fidelity sample points is very small, the R-square of the proposed model exceeds the existing model by more than 0.3, which shows that the proposed method can be applied to reducing the cost of complex engineering design problems.

Details

Engineering Computations, vol. 39 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 9 August 2019

Anand Amrit and Leifur Leifsson

The purpose of this work is to apply and compare surrogate-assisted and multi-fidelity, multi-objective optimization (MOO) algorithms to simulation-based aerodynamic…

Abstract

Purpose

The purpose of this work is to apply and compare surrogate-assisted and multi-fidelity, multi-objective optimization (MOO) algorithms to simulation-based aerodynamic design exploration.

Design/methodology/approach

The three algorithms for multi-objective aerodynamic optimization compared in this work are the combination of evolutionary algorithms, design space reduction and surrogate models, the multi-fidelity point-by-point Pareto set identification and the multi-fidelity sequential domain patching (SDP) Pareto set identification. The algorithms are applied to three cases, namely, an analytical test case, the design of transonic airfoil shapes and the design of subsonic wing shapes, and are evaluated based on the resulting best possible trade-offs and the computational overhead.

Findings

The results show that all three algorithms yield comparable best possible trade-offs for all the test cases. For the aerodynamic test cases, the multi-fidelity Pareto set identification algorithms outperform the surrogate-assisted evolutionary algorithm by up to 50 per cent in terms of cost. Furthermore, the point-by-point algorithm is around 27 per cent more efficient than the SDP algorithm.

Originality/value

The novelty of this work includes the first applications of the SDP algorithm to multi-fidelity aerodynamic design exploration, the first comparison of these multi-fidelity MOO algorithms and new results of a complex simulation-based multi-objective aerodynamic design of subsonic wing shapes involving two conflicting criteria, several nonlinear constraints and over ten design variables.

Article
Publication date: 12 December 2016

Helen Lockett, Geoffrey Waghorn, Rob Kydd and David Chant

The purpose of this paper is to explore the predictive validity of two measures of fidelity to the individual placement and support (IPS) approach to supported employment.

Abstract

Purpose

The purpose of this paper is to explore the predictive validity of two measures of fidelity to the individual placement and support (IPS) approach to supported employment.

Design/methodology/approach

A systematic review and meta-analysis was conducted of IPS programs. In total, 30 studies provided information characterizing 69 cohorts and 8,392 participants. Predictive validity was assessed by a precision and negative prediction analysis and by multivariate analysis of deviance.

Findings

Fidelity scores on the IPS-15 scale of 60 or less accurately predicted poor outcomes, defined as 43 percent or less of participants commencing employment, in 100 percent of cohorts. Among cohorts with IPS-15 fidelity scores of 61-75, 63 percent attained good employment outcomes defined as 44 percent or more commencing employment. A similar pattern emerged from the precision analysis of the smaller sample of IPS-25 cohorts. Multivariate analysis of deviance for studies using the IPS-15 scale examined six cohort characteristics. Following adjustment for fidelity score, only fidelity score (χ2=15.31, df=1, p<0.001) and author group (χ2=35.01, df=17, p=0.01) representing an aspect of cohort heterogeneity, remained associated with commencing employment.

Research limitations/implications

This study provides evidence of moderate, yet important, predictive validity of the IPS-15 scale across diverse international and research contexts. The smaller sample of IPS-25 studies limited the analysis that could be conducted.

Practical implications

Program implementation leaders are encouraged to first focus on attaining good fidelity, then supplement fidelity monitoring with tracking the percentage of new clients who obtain a competitive job employment over a pre-defined period of time.

Originality/value

The evidence indicates that good fidelity may be necessary but not sufficient for good competitive employment outcomes.

Details

Mental Health Review Journal, vol. 21 no. 4
Type: Research Article
ISSN: 1361-9322

Keywords

Article
Publication date: 3 July 2017

Leifur Leifsson and Slawomir Koziel

The purpose of this paper is to reduce the overall computational time of aerodynamic shape optimization that involves accurate high-fidelity simulation models.

Abstract

Purpose

The purpose of this paper is to reduce the overall computational time of aerodynamic shape optimization that involves accurate high-fidelity simulation models.

Design/methodology/approach

The proposed approach is based on the surrogate-based optimization paradigm. In particular, multi-fidelity surrogate models are used in the optimization process in place of the computationally expensive high-fidelity model. The multi-fidelity surrogate is constructed using physics-based low-fidelity models and a proper correction. This work introduces a novel correction methodology – referred to as the adaptive response prediction (ARP). The ARP technique corrects the low-fidelity model response, represented by the airfoil pressure distribution, through suitable horizontal and vertical adjustments.

Findings

Numerical investigations show the feasibility of solving real-world problems involving optimization of transonic airfoil shapes and accurate computational fluid dynamics simulation models of such surfaces. The results show that the proposed approach outperforms traditional surrogate-based approaches.

Originality/value

The proposed aerodynamic design optimization algorithm is novel and holistic. In particular, the ARP correction technique is original. The algorithm is useful for fast design of aerodynamic surfaces using high-fidelity simulation data in moderately sized search spaces, which is challenging using conventional methods because of excessive computational costs.

Article
Publication date: 18 March 2011

Wendi Cross and Jennifer West

The positive outcomes demonstrated in programme efficacy trials and the apparent ineffectiveness of programmes in community settings have prompted investigators and…

Abstract

The positive outcomes demonstrated in programme efficacy trials and the apparent ineffectiveness of programmes in community settings have prompted investigators and practitioners to examine implementation fidelity. Critically important, but often overlooked, are the implementers who deliver evidence‐based programmes. This article distinguishes fidelity at the programme level from implementer fidelity. Two components of implementer fidelity are defined. It is proposed that implementer adherence and competence are related but unique constructs that can be reliably measured for training, monitoring and outcomes research. Observational measures from a school‐based preventive intervention are used to illustrate the contributions of implementer adherence and competence. Distinguishing implementer adherence to the manual from competence in programme delivery is the next step in child mental health programme implementation research.

Details

Journal of Children's Services, vol. 6 no. 1
Type: Research Article
ISSN: 1746-6660

Keywords

Article
Publication date: 21 June 2013

Melissa A. Little, Steven Sussman, Ping Sun and Louise A. Rohrbach

The current study aims to examine the influence of contextual and provider‐level factors on the implementation fidelity of a research‐based substance abuse prevention…

Abstract

Purpose

The current study aims to examine the influence of contextual and provider‐level factors on the implementation fidelity of a research‐based substance abuse prevention program. Also, it aims to investigate whether two provider‐level factors, self‐efficacy and beliefs about the value of the program, statistically moderate and mediate the effects of a provider training intervention on implementation fidelity.

Design/methodology/approach

Using generalized mixed‐linear modeling, the authors examine relationships between program provider‐, organizational, and community‐level factors and implementation fidelity in a sample of 50 high school teachers from 43 high schools in eight states across the USA. Fidelity of implementation was assessed utilizing an observation procedure.

Findings

Implementation fidelity was negatively associated with the urbanicity of the community and the level of teachers’ beliefs about the value of the program, and positively predicted by the organizational capacity of the school. Comprehensive training significantly increased teachers’ self‐efficacy, which resulted in an increase in implementation fidelity.

Research limitations/implications

School‐based prevention program implementation is influenced by a variety of contextual factors occurring at multiple ecological levels. Future effectiveness and dissemination studies need to account for the complex nature of schools in analyses of implementation fidelity and outcomes.

Practical implications

The authors’ findings suggest that both provider‐ and organizational‐level are influential in promoting implementation fidelity. Before implementation begins, as well as throughout the implementation process, training and ongoing technical assistance should be conducted to increase teachers’ skills, self‐efficacy, and comfort with prevention curricula.

Originality/value

The present study is one of the few to examine contextual and provider‐level correlates of implementation fidelity and use mediation analyses to explore whether provider‐level factors mediate the effects of a provider training intervention on implementation fidelity.

Details

Health Education, vol. 113 no. 4
Type: Research Article
ISSN: 0965-4283

Keywords

Article
Publication date: 5 May 2015

Garrison Stevens, Kendra Van Buren, Elizabeth Wheeler and Sez Atamturktur

Numerical models are being increasingly relied upon to evaluate wind turbine performance by simulating phenomena that are infeasible to measure experimentally. These…

Abstract

Purpose

Numerical models are being increasingly relied upon to evaluate wind turbine performance by simulating phenomena that are infeasible to measure experimentally. These numerical models, however, require a large number of input parameters that often need to be calibrated against available experiments. Owing to the unavoidable scarcity of experiments and inherent uncertainties in measurements, this calibration process may yield non-unique solutions, i.e. multiple sets of parameters may reproduce the available experiments with similar fidelity. The purpose of this paper is to study the trade-off between fidelity to measurements and the robustness of this fidelity to uncertainty in calibrated input parameters.

Design/methodology/approach

Here, fidelity is defined as the ability of the model to reproduce measurements and robustness is defined as the allowable variation in the input parameters with which the model maintains a predefined level of threshold fidelity. These two vital attributes of model predictiveness are evaluated in the development of a simplified finite element beam model of the CX-100 wind turbine blade.

Findings

Findings of this study show that calibrating the input parameters of a numerical model with the sole objective of improving fidelity to available measurements degrades the robustness of model predictions at both tested and untested settings. A more optimal model may be obtained by calibration methods considering both fidelity and robustness. Multi-criteria Decision Making further confirms the conclusion that the optimal model performance is achieved by maintaining a balance between fidelity and robustness during calibration.

Originality/value

Current methods for model calibration focus solely on fidelity while the authors focus on the trade-off between fidelity and robustness.

Details

Engineering Computations, vol. 32 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 3 June 2019

Laura Paulauskaite, Angela Hassiotis and Afia Ali

Fidelity data in clinical trials are not only necessary for appraising the internal and external validity, but also could provide useful insights how to improve the…

Abstract

Purpose

Fidelity data in clinical trials are not only necessary for appraising the internal and external validity, but also could provide useful insights how to improve the application of an intervention in everyday settings. The purpose of this paper is to understand the current literature of fidelity measurements in complex interventions for people with intellectual disabilities (ID) and behaviours that challenge.

Design/methodology/approach

The electronic databases MEDLINE, Embase, PsycINFO, Web of Science and CINAHL Plus were searched for studies published between 1990 to 2017 that have mentioned fidelity in randomised controlled trials of complex interventions for people with ID and behaviours that challenge based on positive behaviour support or applied behaviour analysis principles. The authors also searched the grey literature and reference lists.

Findings

Five randomised controlled trials were included in the review. The authors found variable and inconsistent fidelity measurements reported in the studies. The most frequently provided fidelity elements found in four out of five studies were adherence of implementation, dose and some aspects of quality of delivery.

Research limitations/implications

Research recommendations for a standardised approach of measuring fidelity in such studies are suggested.

Originality/value

The first review of such type that confirms the paucity of research measuring fidelity in complex interventions in this population.

Details

Advances in Mental Health and Intellectual Disabilities, vol. 13 no. 3/4
Type: Research Article
ISSN: 2044-1282

Keywords

Article
Publication date: 7 November 2016

Slawomir Koziel, Yonatan Tesfahunegn and Leifur Leifsson

Strategies for accelerated multi-objective optimization of aerodynamic surfaces are investigated, including the possibility of exploiting surrogate modeling techniques for…

325

Abstract

Purpose

Strategies for accelerated multi-objective optimization of aerodynamic surfaces are investigated, including the possibility of exploiting surrogate modeling techniques for computational fluid dynamic (CFD)-driven design speedup of such surfaces. The purpose of this paper is to reduce the overall optimization time.

Design/methodology/approach

An algorithmic framework is described that is composed of: a search space reduction, fast surrogate models constructed using variable-fidelity CFD models and co-Kriging, and Pareto front refinement. Numerical case studies are provided demonstrating the feasibility of solving real-world problems involving multi-objective optimization of transonic airfoil shapes and accurate CFD simulation models of such surfaces.

Findings

It is possible, through appropriate combination of surrogate modeling techniques and variable-fidelity models, to identify a set of alternative designs representing the best possible trade-offs between conflicting design objectives in a realistic time frame corresponding to a few dozen of high-fidelity CFD simulations of the respective surfaces.

Originality/value

The proposed aerodynamic design optimization algorithmic framework is novel and holistic. It proved useful for fast design of aerodynamic surfaces using high-fidelity simulation data in moderately sized search space, which is extremely challenging when using conventional methods due to the excessive computational cost.

1 – 10 of over 4000