Dangers of the Defaults: A Tutorial on the Impact of Default Priors When Using Bayesian SEM With Small Samples

When Bayesian estimation is used to analyze Structural Equation Models (SEMs), prior distributions need to be specified for all parameters in the model. Many popular software programs offer default prior distributions, which is helpful for novel users and makes Bayesian SEM accessible for a broad audience. However, when the sample size is small, those prior distributions are not always suitable and can lead to untrustworthy results. In this tutorial, we provide a non-technical discussion of the risks associated with the use of default priors in small sample contexts. We discuss how default priors can unintentionally behave as highly informative priors when samples are small. Also, we demonstrate an online educational Shiny app, in which users can explore the impact of varying prior distributions and sample sizes on model results. We discuss how the Shiny app can be used in teaching; provide a reading list with literature on how to specify suitable prior distributions; and discuss guidelines on how to recognize (mis)behaving priors. It is our hope that this tutorial helps to spread awareness of the importance of specifying suitable priors when Bayesian SEM is used with small samples.

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Power analysis for parameter estimation in structural equation modeling: A discussion and tutorial

10.31234/osf.io/pj67b ◽

2020 ◽

Author(s):

Yilin Andre Wang ◽

Mijke Rhemtulla

Keyword(s):

Structural Equation Modeling ◽

Sample Size ◽

Latent Variables ◽

Power Analysis ◽

Structural Equation ◽

Structural Equation Models ◽

Regression Coefficient ◽

Equation Modeling ◽

Shiny App ◽

Target Effect

Despite the widespread and rising popularity of structural equation modeling (SEM) in psychology, there is still much confusion surrounding how to choose an appropriate sample size for SEM. Currently available guidance primarily consists of sample size rules of thumb that are not backed up by research, and power analyses for detecting model misfit. Missing from most current practices is power analysis to detect a target effect (e.g., a regression coefficient between latent variables). In this paper we (a) distinguish power to detect model misspecification from power to detect a target effect, (b) report the results of a simulation study on power to detect a target regression coefficient in a 3-predictor latent regression model, and (c) introduce a Shiny app, pwrSEM, for user-friendly power analysis for detecting target effects in structural equation models.

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MHealth Applications for People with Cognitive Impairment and Their Caregivers: A Scoping Review (Preprint)

10.2196/preprints.22474 ◽

2020 ◽

Author(s):

Qing Zhao ◽

Pei Chen ◽

Yu Zhang ◽

Haining Liu ◽

Xianwen Li

Keyword(s):

Cognitive Impairment ◽

Sample Size ◽

Research Design ◽

Scoping Review ◽

Life Support ◽

Small Sample ◽

Mobile Technologies ◽

Control Group ◽

Caregiver Support ◽

The Impact

BACKGROUND Mobile health application has become an important tool for healthcare systems. One such tool is the delivery of assisting in people with cognitive impairment and their caregivers. OBJECTIVE This scoping review aims to explore and evaluate the existing evidence and challenges on the use of mHealth applications that assisting in people with cognitive impairment and their caregivers. METHODS Nine databases, including PubMed, EMBASE, Cochrane, PsycARTICLES, CINAHL, Web of Science, Applied Science & Technology Source, IEEE Xplore and the ACM Digital Library were searched from inception through June 2020 for the studies of mHealth applications on people with cognitive impairment and their caregivers. Two reviewers independently extracted, checked synthesized data independently. RESULTS Of the 6101 studies retrieved, 64 studies met the inclusion criteria. Three categories emerged from this scoping review. These categories are ‘application functionality’, ‘evaluation strategies’, ‘barriers and challenges’. All the included studies were categorized into 7 groups based on functionality: (1) cognitive assessment; (2) cognitive training; (3) life support; (4) caregiver support; (5) symptom management; (6) reminiscence therapy; (7) exercise intervention. The included studies were broadly categorized into four types: (1) Usability testing; (2) Pilot and feasibility studies; (3) Validation studies; and (4) Efficacy or Effectiveness design. These studies had many defects in research design such as: (1) small sample size; (2) deficiency in active control group; (3) deficiency in analyzing the effectiveness of intervention components; (4) lack of adverse reactions and economic evaluation; (5) lack of consideration about the education level, electronic health literacy and smartphone proficiency of the participants; (6) deficiency in assessment tool; (7) lack of rating the quality of mHealth application. Some progress should be improved in the design of smartphone application functionality, such as: (1) the design of cognitive measurements and training game need to be differentiated; (2) reduce the impact of the learning effect. Besides this, few studies used health behavior theory and performed with standardized reporting. CONCLUSIONS Preliminary results show that mobile technologies facilitate the assistance in people with cognitive impairment and their caregivers. The majority of mHealth application interventions incorporated usability outcome and health outcomes. However, these studies have many defects in research design that limit the extrapolation of research. The content of mHealth application is urgently improved to adapt to demonstrate the real effect. In addition, further research with strong methodological rigor and adequate sample size are needed to examine the feasibility, effectiveness, and cost-effectiveness of mHealth applications for people with cognitive impairment and their caregivers.

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Assessing the Impact of Multi-Morbidity and Related Constructs on Patient Reported Safety in Primary Care: Generalized Structural Equation Modelling of Observational Data

Journal of Clinical Medicine ◽

10.3390/jcm10081782 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1782

Author(s):

Ignacio Ricci-Cabello ◽

Aina María Yañez-Juan ◽

Maria A. Fiol-deRoque ◽

Alfonso Leiva ◽

Joan Llobera Canaves ◽

...

Keyword(s):

Primary Care ◽

Patient Safety ◽

Structural Equation ◽

Structural Equation Models ◽

Cross Sectional ◽

Morbidity Burden ◽

Patient Reported ◽

Patient Complexity ◽

Complex Relationships ◽

The Impact

We aimed to examine the complex relationships between patient safety processes and outcomes and multimorbidity using a comprehensive set of constructs: multimorbidity, polypharmacy, discordant comorbidity (diseases not sharing either pathogenesis nor management), morbidity burden and patient complexity. We used cross-sectional data from 4782 patients in 69 primary care centres in Spain. We constructed generalized structural equation models to examine the associations between multimorbidity constructs and patient-reported patient safety (PREOS-PC questionnaire). These associations were modelled through direct and indirect (mediated by increased interactions with healthcare) pathways. For women, a consistent association between higher levels of the multimorbidity constructs and lower levels of patient safety was observed via either pathway. The findings for men replicated these observations for polypharmacy, morbidity burden and patient complexity via indirect pathways. However, direct pathways showed unexpected associations between higher levels of multimorbidity and better safety. The consistent association between multimorbidity constructs and worse patient safety among women makes it advisable to target this group for the development of interventions, with particular attention to the role of comorbidity discordance. Further research, particularly qualitative research, is needed for clarifying the complex associations among men.

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W.S. Gosset and Some Neglected Concepts in Experimental Statistics: Guinnessometrics II

Journal of Wine Economics ◽

10.1017/s1931436100001632 ◽

2011 ◽

Vol 6 (2) ◽

pp. 252-277 ◽

Cited By ~ 3

Author(s):

Stephen T. Ziliak

Keyword(s):

Experimental Design ◽

Sample Size ◽

Large Scale ◽

Statistical Significance ◽

Small Sample ◽

Small Samples ◽

Significant Advance ◽

Economic Approach ◽

Barley Malt ◽

Level Of Significance

AbstractStudent's exacting theory of errors, both random and real, marked a significant advance over ambiguous reports of plant life and fermentation asserted by chemists from Priestley and Lavoisier down to Pasteur and Johannsen, working at the Carlsberg Laboratory. One reason seems to be that William Sealy Gosset (1876–1937) aka “Student” – he of Student'st-table and test of statistical significance – rejected artificial rules about sample size, experimental design, and the level of significance, and took instead an economic approach to the logic of decisions made under uncertainty. In his job as Apprentice Brewer, Head Experimental Brewer, and finally Head Brewer of Guinness, Student produced small samples of experimental barley, malt, and hops, seeking guidance for industrial quality control and maximum expected profit at the large scale brewery. In the process Student invented or inspired half of modern statistics. This article draws on original archival evidence, shedding light on several core yet neglected aspects of Student's methods, that is, Guinnessometrics, not discussed by Ronald A. Fisher (1890–1962). The focus is on Student's small sample, economic approach to real error minimization, particularly in field and laboratory experiments he conducted on barley and malt, 1904 to 1937. Balanced designs of experiments, he found, are more efficient than random and have higher power to detect large and real treatment differences in a series of repeated and independent experiments. Student's world-class achievement poses a challenge to every science. Should statistical methods – such as the choice of sample size, experimental design, and level of significance – follow the purpose of the experiment, rather than the other way around? (JEL classification codes: C10, C90, C93, L66)

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SMALL SAMPLE SIZE SCIENTIST

PEDIATRICS ◽

10.1542/peds.83.3.a72a ◽

1989 ◽

Vol 83 (3) ◽

pp. A72-A72

Author(s):

Student

Keyword(s):

Sample Size ◽

Confidence Intervals ◽

Causal Explanation ◽

Small Sample Size ◽

Small Sample ◽

Small Samples ◽

High Expectations ◽

Sampling Variation ◽

The Law ◽

The Stability

The believer in the law of small numbers practices science as follows: 1. He gambles his research hypotheses on small samples without realizing that the odds against him are unreasonably high. He overestimates power. 2. He has undue confidence in early trends (e.g., the data of the first few subjects) and in the stability of observed patterns (e.g., the number and identity of significant results). He overestimates significance. 3. In evaluating replications, his or others', he has unreasonably high expectations about the replicability of significant results. He underestimates the breadth of confidence intervals. 4. He rarely attributes a deviation of results from expectations to sampling variability, because he finds a causal "explanation" for any discrepancy. Thus, he has little opportunity to recognize sampling variation in action. His belief in the law of small numbers, therefore, will forever remain intact.

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Considering the Impact of Early Trauma on Coping and Pathology to Predict Posttraumatic Growth Among 9-1-1 Telecommunicators

Journal of Interpersonal Violence ◽

10.1177/0886260517716942 ◽

2017 ◽

Vol 35 (21-22) ◽

pp. 4709-4731 ◽

Cited By ~ 2

Author(s):

Melissa J. London ◽

Mary C. Mercer ◽

Michelle M. Lilly

Keyword(s):

Posttraumatic Growth ◽

Childhood Trauma ◽

Indirect Effect ◽

Structural Equation ◽

Structural Equation Models ◽

Trauma Exposure ◽

First Responders ◽

Lifetime Trauma ◽

Early Trauma ◽

The Impact

Recent research has demonstrated that first responders may report posttraumatic growth (PTG), positive psychological changes that arise in the aftermath of a trauma. Less is known regarding the perception of PTG among 9-1-1 telecommunicators, a group of first responders exposed to a high degree of lifetime trauma, including duty-related trauma as well as early and non-duty-related trauma. Moreover, the impact of childhood trauma on the processes involved in the perception of growth is less clear. While some distress is needed to facilitate processes that lead to the perception of PTG, it has been suggested that positive associations between PTG and pathology reflect avoidant coping or represent an illusory component of PTG. Structural equation models were used to examine early trauma exposure, coping, and pathology in predicting PTG among 9-1-1 telecommunicators ( N = 788). In separate models using active and avoidant forms of coping, childhood trauma exposure had an indirect effect on PTG through coping. In a model considering both forms of coping, childhood trauma had an indirect effect on PTG through psychopathology, but not through coping. The results show that early trauma exposure leads to the perception of growth through pathways indicative of both adaptive and maladaptive coping processes.

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Effects of herbivory and its timing on reproductive success of a tropical deciduous tree

Annals of Botany ◽

10.1093/aob/mcaa117 ◽

2020 ◽

Vol 126 (5) ◽

pp. 957-969

Author(s):

Enya N Quiroz-Pacheco ◽

Francisco Mora ◽

Karina Boege ◽

César A Domínguez ◽

Ek del-Val

Keyword(s):

Reproductive Success ◽

Structural Equation ◽

Structural Equation Models ◽

Pollen Grains ◽

Leaf Damage ◽

Deciduous Tree ◽

Herbivore Damage ◽

Male And Female ◽

Foliar Damage ◽

The Impact

Abstract Background and Aims The implications of herbivory for plant reproduction have been widely studied; however, the relationship of defoliation and reproductive success is not linear, as there are many interacting factors that may influence reproductive responses to herbivore damage. In this study we aimed to disentangle how the timing of foliar damage impacts both male and female components of fitness, and to assess when it has greater impacts on plant reproductive success. Methods We measured herbivore damage and its effects on floral production, male and female floral attributes as well as fruit yield in three different phenological phases of Casearia nitida (Salicaceae) over the course of two consecutive years. Then we tested two models of multiple causal links among herbivory and reproductive success using piecewise structural equation models. Key Results The effects of leaf damage differed between reproductive seasons and between male and female components of fitness. Moreover, the impact of herbivory extended beyond the year when it was exerted. The previous season’s cumulated foliar damage had the largest impact on reproductive characters, in particular a negative effect on the numbers of inflorescences, flowers and pollen grains, indirectly affecting the numbers of infructescences and fruits, and a positive one on the amount of foliar damage during flowering. Conclusions For perennial and proleptic species, the dynamics of resource acquisition and allocation patterns for reproduction promote and extend the effects of herbivore damage to longer periods than a single reproductive event and growing season, through the interactions among different components of female and male fitness.

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Sustainable Banking and Bank Performance

Jurnal Ilmiah Akuntansi dan Bisnis ◽

10.24843/jiab.2021.v16.i01.p12 ◽

2021 ◽

Vol 16 (1) ◽

pp. 169

Author(s):

Lilik Handajani ◽

Akram Akram ◽

Ahmad Rifai

Keyword(s):

Structural Equation ◽

Structural Equation Models ◽

Stock Exchange ◽

Bank Performance ◽

Business Practices ◽

Stakeholder Groups ◽

Nonfinancial Performance ◽

Banking Business ◽

Sustainability Reports ◽

The Impact

This research aims to examine the impact of sustainable banking practices and bank characteristics on bank performance. Structural equation models were used to analyze 11 banks listed on the Indonesia Stock Exchange that published sustainability reports consistently during the periods of 2015–2018. Results indicate that while the internalization of sustainability issues in banking business practices does not have a significant impact on bank performance, the characteristics of a bank, which are reflected by institutional and foreign ownership and bank age, have a significant effect on bank financial and nonfinancial performance. The implications of sustainable banking practices are indicated to gain legitimacy from regulators for the existence of financial entities and meet stakeholder expectations, which in practice require trade-off of interests among stakeholder groups. Keywords: sustainable banking, bank performance, bank characteristic

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Patient Engagement in Health Management as a Mediator Between Perceived Risk and COVID-19 Related Distress in Patients With IBD: A Structural Equation Model

Frontiers in Psychiatry ◽

10.3389/fpsyt.2021.733544 ◽

2021 ◽

Vol 12 ◽

Author(s):

Greta Castellini ◽

Lorenzo Palamenghi ◽

Mariarosaria Savarese ◽

Serena Barello ◽

Salvatore Leone ◽

...

Keyword(s):

Psychological Distress ◽

Perceived Stress ◽

Patient Engagement ◽

Perceived Risk ◽

Structural Equation ◽

Structural Equation Models ◽

Health Management ◽

Equation Model ◽

Online Questionnaire ◽

The Impact

Objective: This study aimed to evaluate the impact of the COVID-19 emergency on patients with IBD's psychological distress, understanding the role of patient engagement as a mediator.Methods: An online questionnaire was created, measuring perceived risk susceptibility toward COVID-19, perceived stress, and patient engagement. The questionnaire was distributed to a purposive sample of IBD patients who belonged to the Italian Association for patients with IBD (AMICI Onlus) in April 2020. Structural equation models were implemented.Results: The effect of the perceived risk susceptibility toward COVID-19 contagion on the perceived stress is fully mediated by patient engagement (β = 0.306, p < 0.001). Moreover, the patient engagement mitigates the perceived stress (β = −0.748, p < 0.001) in our sample of IBD patients, and it is negatively influenced by the perceived risk susceptibility toward COVID-19 (β = −0.410, p < 0.001).Conclusion: Patient engagement is the key factor that explains how the perceived risk susceptibility toward COVID-19 affects the perceived psychological distress in patients with IBD, underlining that the perceived risk of contagion increases their perceived level of stress through a decrease of patient engagement.

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An Empirical Analysis of the Impact of Agency Banking on Financial Inclusion in Benue State, Nigeria: Implications for Economic Activities

International Journal of Economics and Finance ◽

10.5539/ijef.v14n2p75 ◽

2022 ◽

Vol 14 (2) ◽

pp. 75

Author(s):

David Terfa Akighir ◽

Tyagher Margaret ◽

Jacob Terungwa Tyagher ◽

Tordue Emmanuel Kpoghul

Keyword(s):

Financial Literacy ◽

Financial Services ◽

Structural Equation ◽

Structural Equation Models ◽

Survey Design ◽

Secondary Data ◽

The State ◽

Financial Inclusion ◽

Economic Activities ◽

The Impact

Twelve (12) out of the Twenty-three (23) local government areas (LGAs) in Benue State do not have the presence of banks over a long period of time. This situation has deprived the inhabitants of these LGAs of access to formal financial services until the advent of agency banking. This study therefore, investigates the impact of agency banking on financial inclusion and economic activities in Benue State focusing on the agency banking activities of First Bank Ltd. The study is anchored on the agency theory and it used a survey design. The study has utilized both primary and secondary data that were analyzed using descriptive statistical tools and structural equation models. Findings of the study have revealed that agency banking activities of First Bank Ltd have immensely enhanced financial inclusion and economic activities in Benue State. However, challenges such as shortages of cash, security problems, network failures, and lack of financial literacy are militating against the smooth operations of the agency banking in the State. On the basis of these findings, the study has recommended among others that, other banks operating in the State should be encouraged to venture into agency banking in the state so as to have a wider coverage of agency banking in the State. Also, government should provide security and partner with the private sector to provide national carrier communication network system to overcome the network failure challenge. Finally, banks should intensify efforts to educate the masses about the validity and potency of agency banking.

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