0000000000249739

AUTHOR

Rubén Daniel Ledesma

Graphical User Interfaces for R

Since R was first launched, it has managed to gain the support of an ever-increasing percentage of academic and professional statisticians. However, the spread of its use among novice and occasional users of statistics have not progressed at the same pace, which can be attributed partially to the lack of a graphical user interface (GUI). Nevertheless, this situation has changed in the last years and there is currently several projects that have added GUIs to R. This article discusses briefly the history of GUIs for data analysis and then introduces the papers submitted to an special issue of the Journal of Statistical Software on GUIs for R.

research product

Using Interactive Graphics to Teach Multivariate Data Analysis to Psychology Students

This paper discusses the use of interactive graphics to teach multivariate data analysis to Psychology students. Three techniques are explored through separate activities: parallel coordinates/boxp...

research product

Enhancing dynamic graphical analysis with the Lisp-Stat language and the ViSta statistical program

Presented is a sample of computerized methods aimed at multidimensional scaling and psychometric item analysis that offer a dynamic graphical interface to execute analyses and help visualize the results. These methods show how the Lisp-Stat programming language and the ViSta statistical program can be jointly applied to develop powerful computer applications that enhance dynamic graphical analysis methods. The feasibility of this combined strategy relies on two main features: (1) The programming architecture of ViSta enables users to add new statistical methods as plug-ins, which are integrated into the program environment and can make use of all the functions already available in ViSta (e.…

research product

Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors

Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling.This study utilized data collected in the COST TU1101 action "Towards safer bicycling through optimization of bicycle helmets and us…

research product

Why women do not use the helmet when riding a bicycle

Women seem to use the helmet when riding a bicycle less frequently than men. Two possible explanations for this behavior are that 1) it is less appalling to them because of lack of comfort or other reasons, or 2) they use bicycles in a more cautious way than men so they feel that they do not need the helmet as much. The present paper explores these two explanations in 5,691 cyclists that responded to an online survey conducted in 17 countries as part of an EU COST project. Answers to questions related to the two aforementioned explanations were analyzed graphically and three questions that showed the most conspicuous differences between males and females were identified. These were: ‘Helme…

research product

Assessing the factor structure of the Behaviour of Young Novice Drivers Scale (BYNDS)

Abstract The Behaviour of Young Novice Drivers Scale (BYNDS) is a self-report instrument to assess risky driving behaviours among youth population. Although previous studies have offered evidences of reliability and validity for the BYNDS scores, results are not conclusive as regards its factor structure. The aim of this research was to assess the factor structure of the BYNDS via Confirmatory Factor Analyses (CFA). The BYNDS was administered to a sample of 832 drivers aged from 18 to 25 years (Argentina = 270, Colombia = 350, and Mexico = 212). Six models were examined: three derived from previous literature, one emerged from an exploratory factor analysis, a unidimensional model, and a bi…

research product

The History of ViSta: The Visual Statistics System

ViSta is a project that focuses on dynamic and interactive graphics for statistics and was initiated by the late Forrest W. Young at the beginning of the 1990s. For over approximately 20 years, Forrest and other collaborators, including the authors of this article, have used ViSta for experimenting with these kinds of graphics in different settings, applying them to different scenarios of data and statistical analysis, searching to develop the right combination of features most appropriate in each case. In this time, ViSta evolved quite considerably, going through what we reckon were three different stages, namely: the initial one setting forth the foundations of ViSta; the second period wh…

research product

Abiding by the law when it does not exist: The case of the helmet bicycle law

To improve the safety of bicycle users, some countries have enacted, or considered enacting, mandatory helmet legislation. Of course, the enactment of such legislation in a country assumes that its citizens will be well-informed of it, and consequently, will use the helmet more frequently than before. However, in the survey described in this paper we found that many people are not aware of the legislation in force in their own country, or, even if they know, they may not necessarily behave as dictated by the law. Thus, the effects of mandatory helmet legislation may be somewhat different than desired or expected. Therefore, the goal of this paper is to ascertain the role of cyclists' knowle…

research product

The Scree Test and the Number of Factors: a Dynamic Graphics Approach

Exploratory Factor Analysis and Principal Component Analysis are two data analysis methods that are commonly used in psychological research. When applying these techniques, it is important to determine how many factors to retain. This decision is sometimes based on a visual inspection of the Scree plot. However, the Scree plot may at times be ambiguous and open to interpretation. This paper aims to explore a number of graphical and computational improvements to the Scree plot in order to make it more valid and informative. These enhancements are based on dynamic and interactive data visualization tools, and range from adding Parallel Analysis results to "linking" the Scree plot with other g…

research product

Dynamic-Interactive Graphics for Statistics (26 years later)

This paper briefly reviews the history of dynamic-interactive graphicsfor statistics, introduces an example of such graphics, and provides a fewglimpses as to the current state of things and the future trends we envision.The general conclusion is that dynamic-interactive graphics for statistics arethriving more than ever as they shift from the desktop to the internet. Thus,dynamic-interactive graphics are becoming increasingly important as they: 1) provide non-experts in statistics with the means to carry out analyses on their own; and 2) teach the basic concepts of statistics to students and practitioners with low to moderate  mathematics skills. Their increasingpopularity makes the lesson…

research product

Mindfulness, inattention and performance in a driving simulator

The following study will explore the link between mindfulness, driver inattention and a number of driving performance variables that were tested using the SIMUVEG driving simulator. 67 subjects between the ages of 19 and 27 completed the mindful attention awareness scale, attention-related driving errors scale and attention-related cognitive errors scale questionnaires, and were evaluated in two driving performance measures: time to line-crossing and mean speed. The results did not show a correlation between driving performance and mindfulness measures; they did show low but significant correlations with driver inattention measures. A regression analysis suggested that the specific measure …

research product