Department Of Statistical Sciences Research Articles

Honours course timetabling and classroom assignment

This work addresses the timetabling problem faced by the Department of Statistical Sciences at the University of Cape Town each year for the honours course or fourth-year class. The approach taken by the department to design the timetable has been a manual one, which is time consuming. An automated approach is proposed in this work, based on mathematical programming models, with the aim to alleviate the burden caused by the manual approach to create such timetable. The proposed mixed integer programming model consists of three phases: The first phase involves the allocation of lecturers to modules based on preferences and expertise, the second phase consists of assigning modules to time slots, and the third phase involves the allocation of available venues for classes on the timetable. The model was applied to real data, collected from the department. The resulting timetabling solutions were compared to the 2022 timetable and validated by the course convenors.

A conversation with Nancy Reid

AbstractNancy Reid was born in September 1952 in Niagara Falls, Canada. She graduated from the University of Waterloo with a Bachelor in Mathematics and a Major in Statistics in 1974. She studied statistics at the University of British Columbia (UBC) where she obtained a Master's in Applied Mathematics in 1976, and at Stanford University where she graduated with a PhD in Statistics in 1979. After spending one year at Imperial College London visiting Sir David Cox, she joined UBC as an Assistant Professor in the Department of Mathematics, and in 1986 she moved to the University of Toronto as a faculty member in the Department of Statistics (now Statistical Sciences) where she has been ever since including serving as Chair between 1997 and 2002. At the time of writing, Nancy has authored over 100 papers and 5 books, including seminal developments in conditional inference, higher‐order asymptotics, composite likelihood, and Bayesian inference. Her outstanding contributions to statistics have been recognized nationally and internationally with many awards, including the President's Award of the Committee of Presidents of Statistical Societies (COPSS), the Gold Medal awarded by the Statistical Society of Canada (SSC), and being elected Foreign Associate of the National Academy of Sciences. In 2017, the International Statistical Review published Nancy's conversation with Ana Maria Staicu [Staicu, A. M. (2017). Interview with Nancy Reid. International Statistical Review, 85(3), 381‐403.], which had a biographical emphasis. Since then, Nancy has continued to support the discipline of statistics in important ways, such as by serving as Director of the Canadian Statistical Sciences Institute (CANSSI) (2015–2019) and Co‐chair of the Institute of Mathematical Statistics' Committee on Ethics (2018–2020). Her research activity continues to be celebrated with important awards such as Fellowship of the Royal Society of London (2018), the inaugural Hollander Distinguished Lectureship at Florida State University (2020), the Distinguished Achievement Award (and Lectureship) from COPSS (2022), and the Guy Medal in Gold from the Royal Statistical Society (2022). In May 2022, the Department of Statistical Sciences at the University of Toronto, in collaboration with CANSSI and the SSC, organized a one‐day conference, “Statistics at Its Best”, in honour of Nancy's 70th birthday. This conversation took place in Toronto around the time of the event. Its focus is on Nancy's views on building a career in statistics, and the challenges and opportunities statisticians encounter within the rapidly evolving data science ecosystem.

Editors’ Note

Population and Development ReviewVolume 48, Issue 4 p. 919-920 Editorial Editors’ Note Raya Muttarak, Raya MuttarakSearch for more papers by this authorJoshua Wilde, Joshua WildeSearch for more papers by this author Raya Muttarak, Raya MuttarakSearch for more papers by this authorJoshua Wilde, Joshua WildeSearch for more papers by this author First published: 27 December 2022 https://doi.org/10.1111/padr.12537 Raya Muttarak, Department of Statistical Sciences, University of Bologna, Via Belle Arti 41, Bologna, 40126, Italy. E-mail: [email protected] Joshua Wilde, Max Planck Institute for Demographic Research, Konrad-Zuse-Str. 1, 18057 Rostock, Germany. E-mail: [email protected] Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume48, Issue4December 2022Pages 919-920 RelatedInformation

Bridging statistics and life sciences education for immunologists: Exploring a significantly impactful collaboration

Abstract Statistical tests and graphs are an important part of any immunological research publication or presentation. However, not all immunologists have the statistical expertise to choose the best methods to evaluate and represent their experiments, and the formal statistics training required by undergraduate immunology curricula is often quite limited. How can we prepare future immunologists for statistical practice in research? As a collaborative effort between the Department of Statistical Sciences and the Human Biology Program at the University of Toronto, a second-year undergraduate course was developed to integrate statistics instruction with research design to improve the quantitative training of life sciences students. In a Scholarship of Teaching and Learning (SoTL) study conducted within the course, student attitudes and self-efficacies for statistics, as well as their abilities to recognize and handle problems related to statistical practice in life sciences research, were assessed through surveys administered at the beginning and end of the course (n=126). Here, we present our team-teaching model and strategies for promoting meaningful connections between statistics and life sciences research through course design, activities and assessments. We also highlight results from our SoTL study, which revealed that 77% of students felt more confident about choosing the correct statistical procedure, while 74% indicated that the course helped increase their confidence with respect to results interpretation. We hope that insights from this teaching partnership and our SoTL findings will help inform future course offerings to better prepare our students to effectively engage with statistics in immunological research.

Leaving the parental home in Italy during the economic crisis

Using the data from the survey “Critical aspects in the work life course in a gender perspective” carried out by the National Institute of Statistics (ISTAT) before the recent economic crisis (2007) and the data from the survey “Youth Project” carried out in 2012 by the Toniolo Institute for Advanced Studies, we analysed a sample of Italian young adults aged between 21 and 29, in order to evaluate the effect of the Great Recession on the intentions to leave the family of origin. Implementing a probit model with sample selection, we found empirical evidence of a relevant impact of the economic downturn on decreasing the intentions of starting an independent life. Emiliano SIRONI, Researcher, Department of Statistical sciences, Catholic University, Milan, Italy. E-mail: emiliano.sironi@unicatt.it . Alessandro ROSINA, Professor of Demography, Department of Statistical sciences, Catholic University, Milan, Italy. E-mail: alessandro.rosina@unicatt.it .

Maternal age and parenting strategies

In recent decades, the age that women give birth to their children has been gradually increasing in many developed countries. This trend may have important consequences for parenting. The present study aims to analyze whether and how maternal age influences parents' strategies with respect to the presence of parents in their children’s daily life. Using data from the 2005 Italian Birth Sample Survey, we focus on the early infancy period and consider three domains of parenting: a) support for the baby’s care (grandparents, babysitter, or creche), b) the mothers’ return to work after childbirth, and c) the father’s time spent with the child. Results show that maternal age has mixed effects depending on the employment status of the mothers. Older unemployed mothers are more prone to adopt traditional parenting models than their younger counterparts. On the contrary, employed older mothers are more likely than younger ones to have less traditional parenting models. Silvia MEGGIOLARO, Researcher, Department of Statistical Sciences, Universityof Padua, Via Cesare Battisti, 241, 35121-Padova, Italy. E-mail: meg@stat.unipd.it . Fausta ONGARO, Professor of Demography, Department of Statistical Sciences, Universityof Padua, Via Cesare Battisti, 241, 35121-Padova, Italy. E-mail: ongaro@stat.unipd.it .

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Projecting the population of the 27 EU Member States by stochastic methods combined with the deterministic projections EUROPOP 2008

The paper presents a stochastic approach to population projections based on micro-simulations of birth-death-immigration-emigration point event processes. This approach allows computing forecast intervals also for conventional population projections and an application is done on the Eurostat population projections 2008-based (EUROPOP2008). The paper shows how it is possible to obtain predictions about all the parameters describing the evolution of a population in a stochastic context, taking into account the expert's opinion as incorporated in deterministic projections. Salvatore BERTINO, Senior Professor, Department of Statistical Sciences, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy. E-mail: salvatore.bertino@uniroma1.it . Eugenio SONNINO, Professor of Demography, Department of Statistical Sciences, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy. Giampaolo LANZIERI, Head, EUROSTAT, Population Unit, Luxembourg. E-mail: giampaolo.lanzieri@ec.europa.eu .

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Is replacement migration actually taking place in low fertility countries

Are migrants replacing “missing” births? We discuss the actual importance of “replacement migration” in the context of the low and lowest-low fertility levels that emerged in Europe, and subsequently in South-East Asia, during the 1990s. After a short introduction on this much debated topic, we take an empirical perspective with a specific focus on birth-cohort replacement migration and working-age population replacement migration. We examine the actual dynamics of the absolute population numbers by birth cohort (independently of the place of birth) in some low-fertility, highly-developed countries, and we also look at aging indicators. Subsequently, we conduct a more detailed analysis of a prototypical lowest-low fertility country, Italy. We conclude that (some) replacement migration is indeed taking place but the extent varies according to the country. Francesco C. BILLARI, Full Professor of Demography, Carlo F. Dondena Centre for Research on Social Dynamics, Department of Policy Analysis and Public Management and Innocenzo Gasparini Institute for Economic Research, Bocconi University, Via Guglielmo Rontgen, n. 1, 20136-Milano - Italy. E-mail: francesco.billari@unibocconi.it . Gianpiero DALLA-ZUANNA, Full Professor of Demography, Department of Statistical Sciences, University of Padua, Via Cesare Battisti, n. 241, Padova, Italy. E-mail: gpdz@stat.unipd.it .

150 years of official population statistics in Italy

The paper contains an overview of the different stages of Italian history underlying the relations between official population statistics and the changes in demographic behaviour since 1861. A crucial point is the role played by institutional organisations and their specific choices in terms of the production of official statistics. The analysis is divided into five different historical periods: from Italian unification to the First World War; the period between the two wars, from World War II to the Sixties; the Seventies; and the last thirty years. In the first decades after unification, the institutional structure led to the enhancement of “political arithmetic” as a tool for the administration of the new state. This perspective was strengthened between the two World Wars, the period of Fascism. After World War II, the availability of institutional data focused mainly on economic dynamics. The subsequent major transformations in the field of family and fertility behaviour pushed for further developments in population studies. Starting in the Seventies, methodological and scientific progress led to a rethinking of the creation of data. Following the line traced by the paradigm shift (from macro to micro), a new phase of data collection started with the implementation of national socio-demographic sample surveys. In the last 30 years, behavioural changes have been further accelerated. However, at the same time, advances in scientific research have led to new explanatory approaches and data collection methods. Roberto IMPICCIATORE, Resercher, Department of Economics, Management and Quantitative Methods, Milan University, Milan, Italy. E-mail: roberto.impicciatore@unimi.it . Rosella RETTAROLI, Professor of Demography, Department of Statistical Sciences, Bologna University, Bologna, Italy. E-mail: rosella.rettaroli@unibo.it .

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Individual, dyadic and network effects in friendship relationships among Italian and foreign schoolmates

One of the effects of the increasing number of foreigners in Italy is the growing presence of immigrants’ children. The transformation of a group of workers into a population involves a perspective aimed above all at analysing integration processes. Among all the factors useful for empirically describing this process, the analysis of friendship relationships uses a perspective that is not yet widely explored and full of interesting implications. The schools attended by native and foreign pupils represent a privileged observatory to analyse social relationships. Thanks to a survey conducted during 2006 on over 17,000 pupils (Italian and foreign) attending first grade secondary school in Lombardy, the most foreign-populated region in Italy, this study intends to investigate the friendship relationships observed inside and outside school classrooms. In particular, the attention is focused on how the actors’ (pupils) characteristics (individual and migratory) support inter-ethnic social relations. In this paper, we use statistical models for the analysis of closed friendship networks. This approach enables us to estimate the actors’ and structural effects on the friendship ties’ presence. The results mainly show that pupils prefer to interact with classmates who are like themselves, even if school classes are privileged places where children of migrants and native pupils come in contact, and therefore where inter-ethnic relationships are encouraged. Giulia RIVELLINI, Associate Professor of Demography, Department of Statistical Sciences, Catholic University, Largo Gemelli 1, 20123-Milano, Italy. E-mail: giulia.rivellini@unicatt.it . Laura TERZERA, Associate Professor of Demography, Department of Statistics, University of Milano Bicocca, Via Bicocca degli Arcimboldi 8, 20126-Milano, Italy. E-mail: laura.terzera@unimib.it . Viviana AMATI, Postdoctoral researcher, Department of Computer and Information Science, University of Konstanz, Box 67, 78457- Konstanz, Germany. E-mail: viviana.amati@uni-konstanz.de

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Statistical modelling of subjective survival probabilities

In this paper, we present a statistical paradigm for discussing and modelling the perception process by which sampled respondents assess their subjective evaluation of the survival probabilities to 75 and 90 years, respectively. The work compares this evaluation for given subjects’ covariates (as gender, education, age, for instance) and shows how a class of models for ordinal data is able to enhance differences and patterns of perceived probabilities in an effective way. Maria IANNARIO, Assistant Professor of Statistics, Department of Statistical Sciences, University of Naples Federico II, Via L. Rodino, 22 – 80138 Naples, Italy. E-mail: maria.iannario@unina.it .. Domenico PICCOLO, Professor of Statistics, Department of Statistical Sciences, University of Naples Federico II, Via L. Rodino, 22 – 80138 Naples, Italy. E-mail: domenico.piccolo@unina.it . DOI: 10.4402/genus-224

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Partnerships in Training

Capital One Financial Corporation supplies credit products in the US. Since 1995, it has followed an information-based strategy, collecting and analyzing data to improve its business decisions. To continue this successful strategy, it must train its analysts in analytical techniques. In a partnership between Capital One and the Department of Statistical Sciences and Operations Research at Virginia Commonwealth University, we developed three training courses in forecasting, optimization, and simulation. These courses have been well received by the analysts and have led to considerable early return on investment with one class project forecasted to reduce costs at the firm’s Richmond, Virginia mail center by more than $2 million annually.

Residual Depression Symptoms Respond to Short-Term CBT

Back to table of contents Previous article Next article Clinical & Research NewsFull AccessResidual Depression Symptoms Respond to Short-Term CBTMark MoranMark MoranSearch for more papers by this authorPublished Online:5 Nov 2004https://doi.org/10.1176/pn.39.21.00390032A significant proportion of patients with recurrent depression might be able to withdraw from medication successfully and stay well for at least six years with a focused course of cognitive-behavioral therapy (CBT), according to a report in the October American Journal of Psychiatry.The study compared short-term CBT (10 30-minute sessions once every other week) versus standard clinical management following successful treatment of a depressive episode with psychopharmacology.“Cognitive-behavior treatment was found to be effective in decreasing the residual symptoms of depression,” the authors wrote. “By deferring psychotherapeutic intervention until after pharmacotherapy, we were able to provide a less intense course of therapy than is customary.. .because psychotherapy could concentrate only on the symptoms that did not abate after pharmacotherapy.”The lead author was Giovanni A. Fava, M.D., of the department of psychology at the University of Bologna, Italy. His colleagues included researchers at the University of Bologna, the department of psychiatry at the State University of New York at Buffalo, and the department of statistical sciences at the University of Padova, Italy.Extending Follow-Up to Six YearsFava and colleagues designed their study as an extension of the 1990 study“ Three-Year Outcome for Maintenance Therapies in Recurrent Depression,” which appeared in the December 1990 Archives of General Psychiatry. That study found that a sequential approach to treatment of recurrent depression, using pharmacotherapy in the acute phase and CBT for residual symptoms, resulted in a significantly lower relapse rate at two-year follow-up.In the current study, Fava and colleagues used a similar design to report six-year outcomes of CBT for prevention of relapse.Forty patients who were diagnosed with recurrent major depression and had been successfully treated with antidepressant drugs were randomly assigned to either CBT or clinical management; in both groups, antidepressant drugs were tapered and discontinued. A six-year follow-up was undertaken, during which no antidepressant drugs were used except in the case of a relapse.Criteria for inclusion in the study included, in addition to successful psychopharmacologic treatment of the most recent depressive episode, the following: a current diagnosis of major depressive disorder, a third or subsequent episode of depression with the immediately preceding episode occurring no more than 2.5 years before the onset of the most recent episode, a minimum 10-week remission between the most recent episode and the immediately preceding episode, and a minimum global severity score of 7 for the most recent episode of depression.Exclusion criteria included history of manic, hypomanic, or cyclothymic features; active drug or alcohol abuse or personality disorder; antecedent dysthymia; and active medical illness.Fava and colleagues noted that the CBT group also received “lifestyle modification” and “well-being therapy.”“Clinical experience has suggested... that recovered depressed patients are often unaware of the long-term consequences of a maladaptive lifestyle, which does not take chronic, minor life stress, interpersonal friction, excessive work,.. .and inadequate rest into proper account,” the authors stated. “We postulated that both the presence of subsyndromal psychiatric symptoms and chronic stress exposure may cause.. .fluctuating and heightened neural or endocrine responses resulting from environmental challenge.”They added that treatment aimed specifically at restoration of positive functioning is also vital. “A specific well-being-enhancing psychotherapeutic strategy was the third main ingredient of the cognitive-behavior approach,” they stated.Findings After Six YearsAt six years the group receiving CBT had a significantly lower relapse rate (40 percent) than the clinical-management group (90 percent). When multiple recurrences were considered, the CBT group had a significantly lower number of relapses than the other group.“The cognitive-behavior intervention provided in this report was quite brief,” the authors commented. “It is conceivable.. .that even better results might have been obtained with longer courses of cognitive-behavior treatment and if patients beginning to experience signs and symptoms of relapse had received additional booster sessions of therapy.”The study, “Six-Year Outcome of Cognitive Behavior Therapy for Prevention of Recurrent Depression,” is posted online at<http://ajp.psychiatryonline.org/cgi/content/full/161/10/1872?>.▪ Am J Psychiatry 2004 161 1872 ISSUES NewArchived