Dr. Symanzik joined the Department of Mathematics and Statistics at Utah State University in 1999. He holds degrees in Statistics (1991) and Computer Science (1992) at the MS level (Universitaet Dortmund, Germany) and a co-major Ph.D. (1996) in these two fields (Iowa State University, Ames, Iowa). Dr. Symanzik's research interests include all forms of statistical graphics and visualization, e.g., static/dynamic/interactive, on the Web, in a geographical framework, and applied to educational and medical data.
This chapter describes the use of XploRe’s commands for reading and writing data files as well as... more This chapter describes the use of XploRe’s commands for reading and writing data files as well as how to set the output format for the output window. Section 15.1 introduces reading and writing simple ASCII data sets. Section 15.2 explains the input format strings which can be used to read arbitrary ASCII data files. Section 15.3 explains the format strings which can be used to write formatted numeric data. Finally, the last Section 15.4 explains how to customize the output window of XploRe.
Journal of Computational and Graphical Statistics, 2011
... Multi-Class Data Exploration Using Space Transformed Visualization Plots Rida E. MOUSTAFA,Ali... more ... Multi-Class Data Exploration Using Space Transformed Visualization Plots Rida E. MOUSTAFA,Ali S. HADI, and Jürgen SYMANZIK ... Ali S. Hadi is Vice Provost, The American University in Cairo, PO Box 74, New Cairo, 11835, Egypt (E-mail: ahadi@aucegypt.edu). ...
Interactive and dynamic statistical graphics enable data analysts in all fields to carry out visu... more Interactive and dynamic statistical graphics enable data analysts in all fields to carry out visual investigations leading to insights into relationships in complex data. Interactive and dynamic statistical graphics involve methods for viewing data in the form of point clouds or modeled surfaces. Higher-dimensional data can be projected into one-, two- or three-dimensional planes in a set of multiple views or as a continuous sequence of views which constitutes motion through the higher-dimensional space containing the data.
Journal of Occupational Rehabilitation, Jun 3, 2008
Introduction:The purpose of this study was to evaluate the inter-rater reliability of hand diagra... more Introduction:The purpose of this study was to evaluate the inter-rater reliability of hand diagrams, which are commonly used in research case definitions of carpal tunnel syndrome (CTS). To evaluate the potential of non-random misclassification of cases, we also studied predictors of rater disagreement as a function of personal and work factors, and of hand symptoms not classic for CTS.Methods:Participants in a longitudinal study investigating the development of CTS completed repeated self-administered questionnaires. Three experienced clinicians, blind to subjects’ work or personal history, independently rated all hand diagrams on an ordinal scale from 0 to 3. Disagreements between ratings were resolved by consensus. Reliability was measured by the weighted kappa statistic. Logistic regression models evaluated predictors of disagreement.Results:Three hundred and thirty-three subjects completed 494 hand diagrams. Eighty-five percent were completed by self-administered questionnaire and 15% by telephone interview. Weighted kappa values representing agreement among the three raters, were 0.83 (95% CI: 0.78, 0.87) for right hand diagrams and 0.88 (95% CI: 0.83, 0.91) for left hand diagrams. Ratings from hand diagrams obtained by telephone interview produced better agreement. Agreement among raters was not affected by subjects’ personal or work factors. Disagreement among raters was associated with the presence of hand/wrist symptoms other than classic CTS symptoms.Conclusions:Overall, high levels of agreement were attained by independent raters of hand diagrams. Personal factors did not affect agreement among raters, but presence of non-CTS symptoms seemed to affect results and should be considered in studies focused on diverse populations with heterogeneity of upper extremity symptoms.
This chapter describes the use of XploRe’s commands for reading and writing data files as well as... more This chapter describes the use of XploRe’s commands for reading and writing data files as well as how to set the output format for the output window. Section 15.1 introduces reading and writing simple ASCII data sets. Section 15.2 explains the input format strings which can be used to read arbitrary ASCII data files. Section 15.3 explains the format strings which can be used to write formatted numeric data. Finally, the last Section 15.4 explains how to customize the output window of XploRe.
Journal of Computational and Graphical Statistics, 2011
... Multi-Class Data Exploration Using Space Transformed Visualization Plots Rida E. MOUSTAFA,Ali... more ... Multi-Class Data Exploration Using Space Transformed Visualization Plots Rida E. MOUSTAFA,Ali S. HADI, and Jürgen SYMANZIK ... Ali S. Hadi is Vice Provost, The American University in Cairo, PO Box 74, New Cairo, 11835, Egypt (E-mail: ahadi@aucegypt.edu). ...
Interactive and dynamic statistical graphics enable data analysts in all fields to carry out visu... more Interactive and dynamic statistical graphics enable data analysts in all fields to carry out visual investigations leading to insights into relationships in complex data. Interactive and dynamic statistical graphics involve methods for viewing data in the form of point clouds or modeled surfaces. Higher-dimensional data can be projected into one-, two- or three-dimensional planes in a set of multiple views or as a continuous sequence of views which constitutes motion through the higher-dimensional space containing the data.
Journal of Occupational Rehabilitation, Jun 3, 2008
Introduction:The purpose of this study was to evaluate the inter-rater reliability of hand diagra... more Introduction:The purpose of this study was to evaluate the inter-rater reliability of hand diagrams, which are commonly used in research case definitions of carpal tunnel syndrome (CTS). To evaluate the potential of non-random misclassification of cases, we also studied predictors of rater disagreement as a function of personal and work factors, and of hand symptoms not classic for CTS.Methods:Participants in a longitudinal study investigating the development of CTS completed repeated self-administered questionnaires. Three experienced clinicians, blind to subjects’ work or personal history, independently rated all hand diagrams on an ordinal scale from 0 to 3. Disagreements between ratings were resolved by consensus. Reliability was measured by the weighted kappa statistic. Logistic regression models evaluated predictors of disagreement.Results:Three hundred and thirty-three subjects completed 494 hand diagrams. Eighty-five percent were completed by self-administered questionnaire and 15% by telephone interview. Weighted kappa values representing agreement among the three raters, were 0.83 (95% CI: 0.78, 0.87) for right hand diagrams and 0.88 (95% CI: 0.83, 0.91) for left hand diagrams. Ratings from hand diagrams obtained by telephone interview produced better agreement. Agreement among raters was not affected by subjects’ personal or work factors. Disagreement among raters was associated with the presence of hand/wrist symptoms other than classic CTS symptoms.Conclusions:Overall, high levels of agreement were attained by independent raters of hand diagrams. Personal factors did not affect agreement among raters, but presence of non-CTS symptoms seemed to affect results and should be considered in studies focused on diverse populations with heterogeneity of upper extremity symptoms.
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