Dr Paul Hewson

Dr Paul Hewson

Associate Professor (Senior Lecturer) in Statistics

School of Computing and Mathematics (Faculty of Science & Environment)


Associate Professor (Senior Lecturer) in Statistics

Careers and Employability Tutor


2005: University of Exeter, PhD in Statistics

1998: Sheffield Hallam University, MSc in Applied Statistics

1988: Plymouth Polytechnic, BSc (hons) First Class in Biological Sciences

Professional membership

Fellow of (2007) / Registered Practitioner of (2006) the Higher Education Academy

Roles on external bodies

Member of advisory group for Department for Transport Project "Road Safety Research Dissemination and Action Learning", October 2007 onwards

Member of RSS Statistical Computing Section Committee 2005 -208

Member of RSS Official Statistics Section Committee 2001 - 2005:

Organised RSS Meetings:

"Assuring Quality of Performance Indicators" 25th April 2002,

"Measuring Congestion" October 2002 (joint meeting

with Transport Statistics User Group),

"Monitoring the Impact of the London Congestion Charge", 29th January 2004,

"Road Safety and Speed Cameras" 10th November 2004 (RSS website)

Teaching interests

MATH 1501 Probability and Inference

MATH2507 (Regression Modelling)

ENVS106 (Environmental Data Handling)

SSU (Performance Indicators in the Health Service)

PgCAP 700: Teaching Statistical Literacy

Other Teaching

August 2014 Science to Data Science Summer School, London

December 2009 "Bayesian Statistics" African Institute of Mathematical Sciences

September 2014,2013, 2012, 2011, 2010, 2009, 2008, 2007 "Probability Crash Course", LMEC Universita degli Studi di Bologna, Facolta di Economia; 25th to 27th October 2005, Short Course "Modelling Count Data", Universita degli Studi di Bologna, Facolta di Economia

24th July 2006 "Multivariate data and modelling", BCS International Summer School in Pattern Recognition

17th to 21st July 2006, July 2007, October 2007, April 2008, September 2008: Short Course "Evidence Based Practice in Road Casualty Reduction,", University of Plymouth

25th October 2007, Introduction to Multilevel Modelling with R, University of Plymouth

6th December 2007, Package building in R, Institute of Child Health, University College London

University of Plymouth Teaching Fellowship 2006-2007: P.J.Hewson and G.C. Crocker "Integrating assessment software with plausible simulation to provide a visual guided learning framework for research design"

Research interests

I am interested in generalised linear mixed models (GLMM), particulary for multivariate responses. These models could be considered as a vector of GLMs with the the assumption that there is an underlying multivariate normal random effect. There are a number of ways of approaching these models, I have tended to focus on Bayesian approaches, and have tended to use MCMC. There seem to be two routes to the multivariate normal distribution, one involves a Wishart prior for the multivariate random effects the alternative is to envisage a latent structure with a smaller number of latent variables and a matrix of loading variables which effect a transformation of the latent variables into the higher dimensionality of the response variables. Most of my recent effort has gone into these latent structure models with a view to superimposing a discrete mixing structure, in particular this seems to yield a good method for unsupervised classfication of multivariate count data. However, there seem to be many possibilities to use latent variables with application specific structures, such as having Conditionally Autoregressive Priors, or temporally correlated sets of latent variables or even to allow for spatial structuring.

To date, I have applied these models to a variety of problems which has included the analysis of performance indicators as well as casualty data arising from road collisions. Most effort at the moment goes into using them in rather large small area estimation problems. However, the exciting thing about these models is the potential to handle a very wide range of multivariate data and they could be a valuable approach in many problem areas.

Here is an attempt to start visualising two univariate random effects models fitted to "STATs 19" motorcycle casualty data for 2000.

Research degrees awarded to supervised students

Golnaz Shahtahmassebi (2012)

Muhannad Al-Saadony (2013)

Grants & contracts

2012-2013 D. Graham and P.J. Hewson, Plymouth University Teaching Fellowship, Enhancing learning with audience response devices. £20,00 total from various sources 2011-2014 R. Thompson, S. Rowland, P.J. Hewson, DEFRA, Investigating whether marine micro-plastics cause harm in the marine environment. £255,145 2011 P.J. Hewson, Philip Poole-Wilson Seed Corn Fund - BUPA Foundation, Using GPUs for small area estimation. £9,500 2011 P.J.Hewson, HE-STEM, Enhancing work-based statistical literacy. £10,000 plus £8,000 for practice adopters follow on project. 2009–2011 E Hellier and P.J.Hewson, Knowledge Transfer Partnership funded by Technology Strategy Board Cornwall Council, Evidence Based Practice in Road Safety. £121, 415 2010-2012 S. Asthana, A. Gibson, T. Bailey, P. Hewson, C. Dibben, G. Moon, NIHR Health Services Research Programme, Equity of Access to Cardiac and Mental Health Services in England. £235,961 2008 S. Asthana, A. Gibson, J. Halliday, P. Hewson, Rural Services Partnership, Resource Allocation in Statutory Service Provision: an Assessment of the Police and Fire Formulae. £20,222 2009 L. Hellier and P.J.Hewson, Vice Chancellor’s Community Research Award, Young motorcycles (working with Plymouth Motorcyclist Group). £6,000 2009 P.J.Hewson, Devon County Council Road Safety Academy e-learning”. £4,200 2008 P.J.Hewson, J.Stander, Y.Cai, Vice Chancellor’s Community Research Award, Understanding Stoke (working with Stoke Damerell Parish). £6,000 2007–2009 S Asthana et al. 2007,2008 , Department of Health, Feasibility of Developing an approach to Person Based Resource Allocation based on Epidemiological data”, “Developing a resource allocation formula at general practice level based on individual patient characteristics (Person-Based Resource Allocation): Mental Health. £121, 269, £191,216 2008-2011 M. Attrill et al., DEFRA, Lyme Bay - A Case Study: Measuring recovery of benthic species; assessing potential ’spillover’ effects and socio-economic changes. £458,324 2008–2010 E Hellier and P.J.Hewson, Knowledge Transfer Partnership funded by ESRC and Devon County Council, Evidence Based Practice in Road Safety. £109, 635 2008 P.J.Hewson, MSOR network, Evaludation of R-books for Guided Learning. £4,500 2008 P. Megicks et al., DEFRA, Understanding of Consumer Attitudes and Actual Purchasing Behaviour, with Reference to Local and Regional Foods. £135,000 2006 P.J.Hewson and G.Crocker, University of Plymouth Teaching Fellowship Award, Virtual environment for experimental design. £5,000 2006 P.J.Hewson, Rees Jeffrey’s Road Fund and Devon County Council, Evidence Based Practice in Road Safety. £7,000 2005–2006 J. Thompson-Coon, G. Rogers, P.J. Hewson, D. Wright, R. Anderson, M. Cramp, S. Jackson, S. Ryder, A. Price, K. Stein, Peninsula Technology Assessment Group (PenTAG), Peninsula Medical School), funded by NHS R&D HTA Programme, Surveillance of Cirrhosis for Hepatocellular Carcinoma: Systematic Review and Economic Analysis.

Research groups

  • Centre for Mathematical Sciences (CMS)
  • Statistics
  • VOYAGE: Risk and decision-making

Papers in mainstream statistical journals

T.C. Bailey and P.J. Hewson (2004), "Simultaneous modelling of multiple traffic safety performance indicators using a multivariate generalised linear mixed model", Journal of the Royal Statistical Society Series A, 167(3): 501-517 (journal website)

P.J.Hewson and K.Yu (2008) "Quantile regression for binary performance indicators" Applied Stochastic Models in Business and Industry 24(5): 401-418 (Journal Website)

P.J. Hewson and T.C. Bailey (2010): Modelling multivariate disease rates with a latent structure mixture model, Statistical Modelling 10(3): 241–264

P.J.Hewson (2011) "ANALYSIS OF HEAD INJURIES USING A BAYESIAN VECTOR GENERALIZED ADDITIVE MODEL" Australian and New Zealand Journal of Statistics 53: 233–246

Applied papers

Ray B Jones, Paul Hewson and Edward R Kaminski (2010) Referrals to a regional allergy clinic - an eleven year audit BMC Public Health 10:790. http://www.biomedcentral.com/1471-2458/10/790

J Thompson Coon, G Rogers, P Hewson, D Wright, R Anderson, S Jackson, S Ryder, M Cramp, K Stein (2008) "Surveillance of cirrhosis for hepatocellular carcinoma: a cost‑utility analysis" British Journal of Cancer 98(7):1166-75 (journal website)

P.J.Hewson (2007) "Quantile Regression provides a fuller analysis of Speed Data". Accident Analysis and Prevention 40(2) 502-510 (Link to journal website)

Thompson-Coon J, Rogers G, Hewson P, Wright D, Anderson R, Cramp M, Jackson S, Ryder S, Price A, Stein K (2007) "Surveillance of cirrhosis for hepatocellular carcinoma: Systematic review and economic analysis". Health Technology Assessment 11 (34):1-206 17767898 (Executive summary)

P.J. Hewson (2005), "Investigating population level trends in head injuries amongst child cyclists in the UK", Accident Analysis and Prevention, 37 (5): 807-815 (journal website) Description of this work in the Guardian

P.J. Hewson (2005), "Epidemiology of child pedestrian casualty rates: Can we assume spatial independence", Accident Analysis and Prevention, 37(4): 651-659 (journal website)

P.J.Hewson (2005), "Cycle helmets and road casualties in the UK",Traffic Injury Prevention 6(2): 127 - 134

P.J. Hewson (2004), "Deprived Children or Deprived Neighbourhoods? A public health approach to the investigation of links between deprivation and injury risk with specific reference to child road safety in Devon County, UK", BMC Public Health 4:15 (journal website)

Applied papers from consultancy work

N. Manghat, Robin Van Lingen, Paul Hewson, Farhan Syed, Nirmal Kakani, Ian Cox, Carl Roobottom, Gareth Morgan-Hughes (2008) "Usefulness of 64-Detector Row Computed Tomography for Evaluation of Intracoronary Stents in Symptomatic Patients WIth Suspected In-Stent Restenosis" American Journal of Cardiology 101(11):1567-73 (journal website)

A.W. Bühler, T.W. Heffernan and P.J. Hewson (2006) "The Soccer Club - Sponsor Relationship: Identifying the Critical Variables for Success", International Journal of Sports Marketing and Sponsorship, 8(4) (Forthcoming)

K. Jethwa, N. Galappathie and P. Hewson (2007) "The effects of a crisis resolution and home based treatment team upon inpatient admissions: A service evaluation report" Psychiatric Bulletin 31:170-172 (journal website)

Papers from Pedagogic Work

P.J.Hewson (2007) "Evidence Based Practice in Road Casualty Reduction" Injury Prevention 13(5) 291-292 (Journal website)

Conference presentations

P.J.Hewson (2007) "Evidence Based Practice in Road Casualty Reduction"  The First Injury Prevention Conference for UK and Ireland, Bristol 2007 (Conference Website
P.J.Hewson (2006) "Smoothed Models for Multivariate Count and Proportion data: an application concerning cycle helmets" , RSS Annual Conference, Belfast, September 2006
P.J.Hewson and T.C.Bailey (2006), "Modelling multivariate cancer rates with a latent structure mixture model", International Biometric Society Conference, Montreal, July 2006
A.E. Bühler, T.W. Heffernan and P.J. Hewson (2006) ‘The impact of trust and commitment on satisfaction in the professional soccer club – sponsor relationship’, EMAC conference 2006, May 2006

P.J.Hewson and K.Yu (2006), "Quantile regression for binary performance indicators", Statistical Methods in the analysis of Performance Indicators (SMAP2006), Cassino, Italy, April 2006
P.J.Hewson and T.C.Bailey (2005), "Classification of multivariate health performance outcomes", poster presented at Royal Statistical Society International Conference, Cardiff, July 2005

P.J.Hewson (2005), "The use of bivariate generalised additive models to investigate the effectiveness of cycle helmets" presented at International Biometic Society Multi-Regional Conference, Leicester, April 2005

P. Hewson and T.C. Bailey (2003), "Use of repeated measures in performance indicator modelling", poster presented at RSS meeting on Performance Surveillance and Modelling January 2003

P.Hewson and T.C.Bailey (2002), "Use of multivariate Generalised Linear Mixed Models (GLMMs) for simultaneous investigation of multiple performance indicators", presented at RSS International Conference, Plymouth, September 2002

T. Ashton, P.Hewson, R.Maini (1995),"Platelet thrombogenic response to polyester can be passivated by fluoropolymer surface treatment", poster presented at the 12th European Society of Biomaterials Conference, Porto 1995

I.Sommer, P.Hewson, P.G.E. Kennedy (1990), "HSV-1 Infection of Optic Nerve Cells in vitro", poster presented at the VIIIth International Congress of Virology, Berlin 1990

Reports & invited lectures

Invited Presentations

J.P.Phillips and P.J.Hewson (2008) "Evidence based practice: origins, beacon legacy and KTP" Institute of Highways Incorporated Engineers South West Meeting February 2008

P.J.Hewson (2008) "Evidence Based Practice" Urban Design Group, London, January 2008

P.J.Hewson (2007) "R-books - integrating R into an e-book" UseR! 2007 Conference, Iowa State University Presentation (conference website)
P.J.Hewson (2007) "Spatial Multivariate Multilevel model for QoF indicators" Primary Care Study Group, Royal Statistical Society, London March 2007 (slides, 4.7Mb)
P.J.Hewson (2006) "Evidence led policy" Parliamentary Advisory Council for Transport Safety Conference, Royal Society of Arts, London, October 2006 (PACTs website including slides)
P.J.Hewson(2006) "Bivariate GAMs and the population level effectiveness of cycle helmets", Insitute of Child Health, Feb 2006
P.J.Hewson(2005) "Latent variable models for simultaneous investigation of multivariate cancer rates", Universita degli Studi di Bologna, Oct 2005

P.J.Hewson (2005), "Multilevel models for environmental applications", Societa Italiana di Statistica, University of Messina September 2005 Intermediate Conference, Statistica e ambiente - Invited Papers, pg. 197-210 ISBN 88-7178-531-2

P.J.Hewson (2005), "Multilevel models for environmental applications", RSS Local Group Meeting (South West) June 2005

P.J.Hewson (2004), "20mph; Do we make robust enough assessments of collision data and how else do we measure success?", presented at one-day conference at Aston University September 2004: "20mph is plenty: is there enough evidence?"

P.J.Hewson (2004), "Are we getting better? A discussion of what modelling can reveal about trends in vulnerable road user casualties", presented at RoSPA 69th Road Safety Congress, Cardiff, March 2004.

P.J.Hewson (2003), "Speed Statistics", presented at Institute of Highways and Transportation regional meeting, 6th March 2003

P.J.Hewson (2002), "Speed Statistics", presented at Institute of Road Safety Officers regional meeting: "Getting Off Speed", 30th October 2002

Reports and articles in non-peer reviewed publications

P.J.Hewson (2008) "Evidence Based Practice" Urban Design 105(Winter):29-32 (By Invitation)

P.J.Hewson (2005), "Mantled in Mist, the importance of evidence in the speed camera debate", Traffic Engineering and Control, January 2005

P.J. Hewson (2004), "Separating signals from noise: assessing road safety performance indicators",

Traffic Engineering and Control, 45(6): 210-213

P.J. Hewson (2002), "An exploratory data analysis of motorcycle Fatal and Serious Collisions in Devon 1996 - 2001" Devon County Council, ISBN 1-85522-894-7

P.J. Hewson (2002), "A model approach", PSBS News 2:12-13

Other academic activities

Additional information

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Multivariate Statistics with R (work in Progress)

A course I taught at the African Institute of Mathematical Sciences

My entry on academia.edu (has some teaching materials posted)

My "engaging researcher" profile

CRAN task view: Multivariate Statistics

University of Plymouth Statistics Group


Linked-In profile


The Wild Wild