scholarly journals Comparing predictive accuracy in small samples using fixed‐smoothing asymptotics

2020 ◽  
Vol 35 (4) ◽  
pp. 391-409 ◽  
Author(s):  
Laura Coroneo ◽  
Fabrizio Iacone
Keyword(s):  
Predictive Accuracy ◽  
Small Samples

scholarly journals A Hybrid PSO–SVM Model Based on Safety Risk Prediction for the Design Process in Metro Station Construction

2020 ◽  
Vol 17 (5) ◽  
pp. 1714 ◽  
Author(s):  
Ping Liu ◽  
Mengchu Xie ◽  
Jing Bian ◽  
Huishan Li ◽  
Liangliang Song
Keyword(s):  
Linear Relationship ◽  
Risk Prediction ◽  
Design Process ◽  
Predictive Accuracy ◽  
Small Samples ◽  
Metro Station ◽  
Safety Risk ◽  
Average Accuracy ◽  
Svm Model ◽  
Test Sets

Incorporating safety risk into the design process is one of the most effective design sciences to enhance the safety of metro station construction. In such a case, the concept of Design for Safety (DFS) has attracted much attention. However, most of the current research overlooks the risk-prediction process in the application of DFS. Therefore, this paper proposes a hybrid risk-prediction framework to enhance the effectiveness of DFS in practice. Firstly, 12 influencing factors related to the safety risk of metro construction are identified by adopting the literature review method and code of construction safety management analysis. Then, a structured interview is used to collect safety risk cases of metro construction projects. Next, a developed support vector machine (SVM) model based on particle swarm optimization (PSO) is presented to predict the safety risk in metro construction, in which the multi-class SVM prediction model with an improved binary tree is designed. The results show that the average accuracy of the test sets is 85.26%, and the PSO–SVM model has a high predictive accuracy for non-linear relationship and small samples. The results show that the average accuracy of the test sets is 85.26%, and the PSO–SVM model has a high predictive accuracy for non-linear relationship and small samples. Finally, the proposed framework is applied to a case study of metro station construction. The prediction results show the PSO–SVM model is applicable and reasonable for safety risk prediction. This research also identifies the most important influencing factors to reduce the safety risk of metro station construction, which provides a guideline for the safety risk prediction of metro construction for design process.

scholarly journals A New Multinomial Accuracy Measure for Polling Bias

2014 ◽  
Vol 22 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Kai Arzheimer ◽  
Jocelyn Evans
Keyword(s):  
Predictive Accuracy ◽  
Multinomial Logit Model ◽  
Small Samples ◽  
Weighted Averages ◽  
Accuracy Index ◽  
Random Samples ◽  
Accuracy Measure ◽  
Folded Normal Distribution ◽  
Summary Index ◽  
Election Polls

In this article, we propose a polling accuracy measure for multi-party elections based on a generalization of Martin, Traugott, and Kennedy's two-party predictive accuracy index. Treating polls as random samples of a voting population, we first estimate an intercept only multinomial logit model to provide proportionate odds measures of each party's share of the vote, and thereby both unweighted and weighted averages of these values as a summary index for poll accuracy. We then propose measures for significance testing, and run a series of simulations to assess possible bias from the resulting folded normal distribution across different sample sizes, finding that bias is small even for polls with small samples. We apply our measure to the 2012 French presidential election polls to demonstrate its applicability in tracking overall polling performance across time and polling organizations. Finally, we demonstrate the practical value of our measure by using it as a dependent variable in an explanatory model of polling accuracy, testing the different possible sources of bias in the French data.

847: Institutional Variability in Predictive Accuracy of Urinary Cytology for Prediction of Transitional Cell Carcinoma Recurrence

2005 ◽  
Vol 173 (4S) ◽  
pp. 230-230
Author(s):  
Serge Benayoun ◽  
Shahrokh F. Shariat ◽  
Paul Perrotte ◽  
Martin G. Friedrich ◽  
Craig D. Zippe ◽  
...  
Keyword(s):  
Transitional Cell Carcinoma ◽  
Cell Carcinoma ◽  
Predictive Accuracy ◽  
Transitional Cell ◽  
Urinary Cytology

Applying the Anderson-Darling Test to Suicide Clusters

Crisis ◽  
2013 ◽  
Vol 34 (6) ◽  
pp. 434-437 ◽  
Author(s):  
Donald W. MacKenzie
Keyword(s):  
Poisson Process ◽  
Goodness Of Fit ◽  
Small Samples ◽  
Massachusetts Institute Of Technology ◽  
Homogeneous Poisson Process ◽  
Cornell University ◽  
The Difference ◽  
Suicide Clusters ◽  
Institute Of Technology ◽  
Anderson Darling

Background: Suicide clusters at Cornell University and the Massachusetts Institute of Technology (MIT) prompted popular and expert speculation of suicide contagion. However, some clustering is to be expected in any random process. Aim: This work tested whether suicide clusters at these two universities differed significantly from those expected under a homogeneous Poisson process, in which suicides occur randomly and independently of one another. Method: Suicide dates were collected for MIT and Cornell for 1990–2012. The Anderson-Darling statistic was used to test the goodness-of-fit of the intervals between suicides to distribution expected under the Poisson process. Results: Suicides at MIT were consistent with the homogeneous Poisson process, while those at Cornell showed clustering inconsistent with such a process (p = .05). Conclusions: The Anderson-Darling test provides a statistically powerful means to identify suicide clustering in small samples. Practitioners can use this method to test for clustering in relevant communities. The difference in clustering behavior between the two institutions suggests that more institutions should be studied to determine the prevalence of suicide clustering in universities and its causes.

The German Version of the Satisfaction With Life Scale (SWLS)

2011 ◽  
Vol 27 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Heide Glaesmer ◽  
Gesine Grande ◽  
Elmar Braehler ◽  
Marcus Roth
Keyword(s):  
Convergent Validity ◽  
Satisfaction With Life ◽  
Age Groups ◽  
Population Based ◽  
Factorial Invariance ◽  
Satisfaction With Life Scale ◽  
Small Samples ◽  
Cross Sectional ◽  
Confirmatory Factor Analyses ◽  
Life Scale

The Satisfaction with Life Scale (SWLS) is the most commonly used measure for life satisfaction. Although there are numerous studies confirming factorial validity, most studies on dimensionality are based on small samples. A controversial debate continues on the factorial invariance across different subgroups. The present study aimed to test psychometric properties, factorial structure, factorial invariance across age and gender, and to deliver population-based norms for the German general population from a large cross-sectional sample of 2519 subjects. Confirmatory factor analyses supported that the scale is one-factorial, even though indications of inhomogeneity of the scale have been detected. Both findings show invariance across the seven age groups and both genders. As indicators of the convergent validity, a positive correlation with social support and negative correlation with depressiveness was shown. Population-based norms are provided to support the application in the context of individual diagnostics.

Assessing Person Fit With the Information Matrix Test

Methodology ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Jochen Ranger ◽  
Jörg-Tobias Kuhn
Keyword(s):  
Simulation Study ◽  
Type I Error ◽  
Information Matrix ◽  
Small Samples ◽  
Type I ◽  
Person Fit ◽  
Power Of The Test ◽  
Order Expansion ◽  
Trait Stability ◽  
Information Matrix Test

In this manuscript, a new approach to the analysis of person fit is presented that is based on the information matrix test of White (1982) . This test can be interpreted as a test of trait stability during the measurement situation. The test follows approximately a χ2-distribution. In small samples, the approximation can be improved by a higher-order expansion. The performance of the test is explored in a simulation study. This simulation study suggests that the test adheres to the nominal Type-I error rate well, although it tends to be conservative in very short scales. The power of the test is compared to the power of four alternative tests of person fit. This comparison corroborates that the power of the information matrix test is similar to the power of the alternative tests. Advantages and areas of application of the information matrix test are discussed.

Tests: Small samples, large consequences.

1993 ◽  
Vol 48 (4) ◽  
pp. 393-399 ◽  
Author(s):  
W. Grant Dahlstrom
Keyword(s):  
Small Samples
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