Columns and Articles

A Statisticians Role in the Pandemic of Misinformation (President's Column - August 2021)

Warren Brettenny - 20 August 2021

As we all adjust to a second year of “pandemic life”, I think it prudent that the president’s column should focus not only on what SASA is doing, but also the potential role that statisticians, as data experts, can play in our country during this increasingly difficult and trying time.


I was watching an interview with a medical correspondent, Dr Jon LaPook from NYU Langone Medical Center, who mentioned that we, as a global community, are in fact facing two pandemics. Firstly - and predominantly - the COVID-19 pandemic and secondly, with growing influence, a pandemic of misinformation and disinformation.


The former has had devastating effects on our lives, livelihoods and families. Outside of our own individual responsibilities to wear masks, stay socially distant and get vaccinated, the core responsibility to solve this pandemic fell (and continues to fall) into the hands of the virologists, microbiologists and chemists to create a safe and effective vaccine. Progress in this regard has been exemplary. With multiple vaccines developed and available, we are currently in a position we never dreamed possible even a decade ago. Statisticians, no doubt, played an important role in the progress that has been made in this area and I am proud that this is the case. The role of statisticians and data experts in this endeavour, however, is well defined and structured and their findings and results are subject to rigorous peer review.


The second pandemic (according to Dr LaPook) - as if it wasn’t bad enough that COVID-19 is wreaking havoc in our lives - is the “pandemic” of misinformation and disinformation. This “pandemic” complicates and frustrates the progress made by the scientists tasked with eradicating the pandemic and may indeed slow down the vaccine rollout and, in so doing, force us to live with COVID-19 for longer. In this “pandemic” of misinformation and disinformation, the role of statisticians and data experts is not well defined and often not even considered - but our role is nonetheless important. Misinformation and disinformation, while similar in name, carry somewhat different interpretations based on the context and intent of the information provided. Misinformation is information or interpretations of data which are inaccurate and/or are provided without the correct context - whether there is an intent to deceive or not. Disinformation, on the other hand, occurs when this information is presented with the direct intent to deceive. Either way, this information - which can come in the form of “half-truths” or outright lies - when proliferated, can have dire consequences on a personal, national and global level. A simple example of a “half-truth” is to compare only the COVID-19 case numbers of a large metropolitan city to those in a small town or village. Without the context of the population size and/or density of each of the compared cities, this only tells some of the whole (or true) story. It is in these cases that the role of statisticians - or indeed those who are simply data literate - is paramount.


At an educational level, our training of statistics students needs to emphasize the importance of context in the presentation of results. From the very foundations of the graphical and tabular representations of data to the most advanced modelling techniques, misrepresentations or misinterpretations of data and results need to be rooted out. We need to train our students to engage with a problem not only on the micro (solution) level but always with the bigger picture firmly in mind - so all conclusions that are drawn are accurate, relevant and unambiguous. This is particularly important to the research of postgraduate students - so instilling this way of thinking at an undergraduate level is exceedingly important.


Added to this, from a professional point of view, we need to call out these misrepresentations of data wherever they occur - from social media posts, to news broadcasts, to conversations with family and friends and even presentations by our senior colleagues. As trained experts in data analysis, the onus and responsibility - whether welcome or not - falls on us to set the record straight in times of confusion and the abuse of data. At the very least, our responsibility is to call into question any dubious conclusions from data by those with the influence to propagate misleading information. As a community we have a role to play and we should not be a shrinking violet in the face of such a misuse of our chosen discipline.


On a more administrative note, I am pleased to inform everyone that we are making great progress in our transition to a new and updated platform. Teething issues are a reality and I thank every one of you for your patience and understanding. We are aiming to host several online webinars in the coming weeks and months and I hope that you make the effort to engage with these. Furthermore, we are collaborating with the NGA-MaSS, the ICM, and NITheCS to bring additional potential benefits and opportunities to our members and society at large. Lastly, I would like to encourage you to attend our SASA 2021 hybrid conference, which will be hosted by the Department of Statistics and Actuarial Sciences at Stellenbosch University. Our return to hosting a conference will coincide with the 75th anniversary celebration of the department and is sure to be a very enjoyable and educational experience.

Keep well and stay safe

A brief history of Bayesian statistics at the University of the Free State - Department of Mathematical Statistics and Actuarial Science

Andréhette Verster - 1 July 2021

Bayesian Statistics has been (and still is) synonymous with the University of the Free State. Over the years Bayesian Statistics became like favourite pieces of furniture in our department, the kind that just fits comfortably into any space.


Where did it all start? I would say it all started with three extraordinary academic pioneers that were intrigued, curious and open to ideas that involved a different way of thinking (often frowned upon in those early days). These three pioneers are Professors Danie de Waal, Abrie van der Merwe and Piet Groenewald.


Due to his interest in the then “new” Bayesian ideas, Prof de Waal decided to present a postgraduate course in Bayesian Statistics in 1977. This course was based on a book by De Groot (1969) about Decision Theory. Prof de Waal’s knowledge of distribution theory, especially multivariate, provided him a strong basis to build on. He was so interested in these Bayesian concepts that he presented his research at a conference in 1975 in Edmonton, Canada. During this conference, Seymour Geisser (the well-known Bayesian that started the idea of sample re-use) from the University of Minnesota, was impressed with his work and visited the University of the Free State in 1978. This was the beginning of various famous Bayesians that visited our department, such as Jim Zidek in 1980 and 1982, Jim Berger in 1985 and 1995 and Arnold Zelner in 1998 (Zelner then also presented a postgraduate course for 3 months on Bayesian Statistics). More recent notable visitors include Sanjib Basu in 2002, Edward George in 2008, Trivellore Raghunathan in 2013, and Donald Rubin in 2015.



In 1978, Prof van der Merwe went on sabbatical leave for 6 months where he worked with Jim Zidek at the University of British Columbia in Vancouver. The study was mostly focused on empirical Bayesian estimators. Prof Abrie, as he is widely known, published in many areas of Bayesian statistics, and was particularly known for his knowledge of hierarchical models (on which he taught a third-year course in the early 2000s).



The postgraduate Bayesian course was taken over in 1980 by Prof Groenewald who presented the course for many years and made it his own research area of expertise. His ability to draw up sampling strategies for complex posteriors is particularly impressive. Later, around 2002, Dr Isabel Garish started to present an undergraduate Bayes course, which is still taught in 2021. A postgraduate course is also still presented annually, but the nature of the course changed dramatically when it was taken over by Dr Sean van der Merwe in 2015.



The Valencia International Meetings on Bayesian Statistics were highlights in their research careers. Some of the conferences that they attended were in Altea (1987), in Penïscola (1991), in Alicante (1994) and in Alcossebre (1998). The 1991 conference in Penïscola (attended by Professors Danie de Waal, Piet Groenewald, Daan Nel and Abrie van der Merwe as well as all their spouses) was known for the introduction of the Gibbs sampling methods.



As an interesting side note: although the Valencia conferences were held every 4th year, there was only a 3-year gap between the 1991 and 1994 meetings. This was due to José-Miguel Bernardo (the founder and organizer of the Valencia meetings) who had to assist in Spain’s governmental elections in 1995.



The International Society for Bayesian Analysis (ISBA) conferences only started in 1993, with the 4th ISBA meeting held in Cape Town in 1996. Eventually, the two (Valencia and ISBA) joined in 2010.



As a student, I had the privilege to take both undergraduate and postgraduate Bayes courses. I later did my Ph.D. under the supervision of Prof De Waal, where various Bayesian techniques were considered. In a way, I feel that I was “born” into this “religion”, I was raised by the best! So how can I not love, respect and cherish the field of Bayesian Statistics? I can only hope to play a part in paying the legendary forward.



President's Column - April 2021

Warren Brettenny - 19 April 2021

In preparation for writing this column, I read through the columns of my predecessors as President of SASA. The first thing that struck me was the high calibre of academic and professional that have occupied this position before me, and I feel humbled to join their ranks. What was also striking was how clearly and definitively the world, and the community as we know it, has changed since the last column was penned.

As vice-president in 2020, I found myself on the executive committee in a period of considerable challenges and uncertainties. Since these were a result of the COVID-19 pandemic, these challenges were not limited to my role on the executive committee – but also in my role as head of the Department of Statistics at Nelson Mandela University. It is in these roles that the organisational impact of such a debilitating time became overwhelming apparent. As an organisation SASA needed to make tough decisions early and consider circumstances which were unfathomable just a few weeks prior.

Having returned from a conference trip to Boston just a few days earlier, I was back in Johannesburg in January 2020 for my first meeting of the Executive Committee (EC). It was here that I saw the dedication and passion of a handful of people who were giving of their time – voluntarily – to ensure that SASA remains relevant and that our community is well served. It is these valued members that keep SASA going and I am very grateful to them. After the meeting we had our plans made and our path set for 2020. Then it all changed. With the announcement of the pandemic and subsequent national shutdowns, the association needed to reassess their strategy for 2020. It was decided, with great sadness, that amongst other meetings and seminars, our flagship event – the annual conference – would have to be cancelled. I thank the community for their understanding of this difficult decision, as it was believed to be in everyone’s best interests. Without a conference to organise, and having to contend with virtual meetings, our committee used this time to reflect on our role in the national statistics landscape. The new normal for statistics as and educator, researcher or professional, will be considerably different. This is the challenge we face as I begin my term as president.

Having not held a conference in 2020, I am unable to reflect on the successes of such in this column, but rather I choose to focus on the path ahead as I take the helm. With the world in a state of transition it is wise to ensure that our association takes the opportunity to make some changes as well. You might have noticed a move from our traditional registration platform to a more dynamic and member engaging platform. As with any change, there will be teething problems and I ensure you that if you encounter any such issues please contact us – we will resolve it in short order. The purpose of the change was to streamline our communications with our members, our financial responsibilities and to offer our members a more engaging experience, thus helping us to fulfil our mission as an association.

Through this platform we are also looking to expand our reach as an organisation and part of that is tied into having a significant online presence both traditionally and on social media platforms. To this end, we will engage with universities and private companies alike to assist them in reaching a wider audience in all areas of South Africa. This may take the form of working with institutions to broadcast seminars and communications throughout the nation so that knowledge and opportunities are not siloed in single institutions. This will help universities to share their valuable research and encourage networking between institutions. Our new treasurer, Dr Carel van der Merwe, and our secretary, Dr Chantelle Clohessy, have been instrumental in driving our efforts in this regard thus far, and I am indebted to them for their continued hard work.

In closing, I would like to extend my sincere gratitude to Prof ‘Maseka Lesaoana who guided our association through a difficult 2020. In addition, I would like to congratulate the Stellenbosch Department of Statistics and Actuarial Science on reaching their 75th anniversary this year and thank them for their willingness to host the 2021 conference in these uncertain times. We owe them our support and wish them all of the best in their preparations for what is sure to be a great conference.

If there is anything that you would like the association to address or consider, my door is open (so to speak) – please send any suggestions to president@sastat.org. Our aim is to continue to be an association that best serves you, and your