Associate Professor Emlyn Williams

Dr Emlyn Williams is an accredited statistician with a PhD in Mathematical Statistics from the University of Edinburgh.

Emlyn worked as a statistical consultant with CSIRO for 35 years before joining the SCU in 2006 where he was Director of the Unit until retiring in 2013.  He has wide experience in the application of statistical methods and has published over 140 journal articles and 2 books.

Emlyn's main areas of research interest are in the design and analysis of experiments and the development of mixed models for use in practice.

He has given many short courses in Australia and overseas with a focus on statistical training in conjunction with computer packages. He has served on the Central Council of the International Biometric Society and has been an Associate Editor for both the Australian and New Zealand Journal of Statistics and Biometrics.

In 2019 he received the E.A. Cornish Award from the Australasian Region of the International Biometric Society in recognition of his longtime service to the Biometric Society and to the advancement of Biometry.

He is a Guest Editor for the December 2020 issue of the Journal of Agricultural, Biological and Environmental Statistics entitled “Recent Advances in Design and Analysis of Experiments and Observational Studies in Agriculture”.

Recent Publications

Piepho,H.P., Williams,E.R. and Prus,M. (2024). Assessing the efficiency and heritability of blocked tree breeding trials. Tree Genetics and Genomes 20, 38 https://doi.org/10.1007/s11295-024-01673-7.

Piepho,H.P, Madden,L.V. and Williams,E.R. (2024).  The use of fixed study main effects in arm-based network meta-analysis. Research Synthesis Methods, https://doi.org/10.1002/jrsm.1721.

Piepho,H.P. and Williams,E.R. (2024): Factor-analytic variance-covariance structures for prediction into a target population of environments. Biometrical Journal 66, doi.org/10.1002/bimj.202400008

James,A.T. and Williams,E.R. (2024) Projection matrices and the sweep operator. arxiv:2404.08883

Williams, E.R., Harwood, C.E., and Matheson, A.C. (2024). Experimental design and analysis for tree improvement, 3rd edition. Canberra: CSIRO Publishing. https://www.publish.csiro.au/book/8100/.

Rance, S.J., Cameron, D.M., Williams, E.R., and Gosper, C.R. (2024). Fertilisation with P, N and S requires additional Zn for healthy plantation tree growth on low fertility savanna soils. Soil Research 62, SR23128. DOI: https://doi.org/10.1071/SR23128.

Rance, S.J., Cameron, D.M., Gosper, C.R., and Williams, E.R. (2024). Plantation tree growth responses to P, N, K and minor and trace elements on low fertility savanna soils. Soil Research 61(3), 255 – 266. DOI: https://doi.org/10.1071/SR21259.

Piepho, H.P., Boer, M.P. and Williams, E.R. (2022). Two-dimensional P-spline smoothing for spatial analysis of plant breeding trials. Biometrical Journal.  https://doi.org/10.1002/bimj.202100212

Williams, E.R., Forde, C.G., Imaki, J. and Oelkers, K. (2021). Experimental design in practice. The importance of blocking and treatment structures. Australian & New Zealand Journal of Statistics 63, 455-467.

Piepho, H.P. and Williams, E.R. (2021). Regression models for order-of-addition experiments.  Biometrical Journal 63, 1673-1687.

Piepho, H.P., Williams, E.R. and Michel, V. (2021). Generating row-column field experimental designs with good neighbour balance and even distribution of treatment replications.  J. Agronomy and Crop Sci. https://doi.org/10.1111/jac.12463

Piepho, H.P., Templeman, R.J and Williams, E.R. (2020). Guest Editors’ Introduction to the Special Issue on “Recent advances in Design and Analysis of Experiments and Observational Studies in Agriculture”. J. Agric., Biol. and Environ. Statist. 25, 453-6.

Boer, M.P., Piepho, H.P. and Williams, E.R. (2020). Linear Variance, P-splines and neighbour differences for spatial adjustment in field trials: How are they related? J. Agric., Biol. and Environ. Statist. 25, 676-98.

Bailey, R.A., Cameron, P., Soicher, L.H. and Williams, E.R. (2020). Substitutes for the non-existent square lattice designs for 36 varieties. J. Agric., Biol. and Environ. Statist. 25, 487-99.

Rance, S.J., Cameron, D.M., Gosper, C.R. and Williams, E.R. (2020). Multiple soil element and pH interactions constrain plant performance on tropical soils with a long history of fire. Soil Res.58, 335-45.

Hardner, C., Costa e Silva, J., Williams, E., Meyers, N. and McConchie, C. (2019). Breeding new cultivars for the Australian Macadamia Industry. HortScience 54(4): 621-628.

Williams, E.R and Piepho, H.P. (2019) Error variance bias in neighbour balance and evenness of distribution designs.  Australian & New Zealand Journal of Statistics 61(4): 466-73.

Piepho, H.P, Madden, L.V. & Williams, E.R. (2018). Contribution to the discussion of “When should meta-analysis avoid hidden normality assumptions?” Using general purpose GLMM software for meta-analysis. Biometrical Journal, 60, 1059-61.

Piepho, H.P., Michel, V. and Williams, E.R. (2018). Neighbour balance and evenness of distribution of treatment replications in row-column designs.  Biometrical Journal, 60, 1173-89.

Sabastian, G.E., Kanowski, P., Williams, E.R. and Roshetko, J.M. (2018). Tree diameter performance in relation to site quality in smallholder timber production systems in Gunungkidul, Indonesia. Agroforestry Systems 92, 103-15.

Williams, E.R. and Piepho, H.P. (2018). An evaluation of error variance bias in spatial designs. J. Agric., Biol. and Environ. Statist. 23, 1-8.

Piepho, H.P, Madden, L.V., Roger, J., Payne, R.P. and Williams, E.R. (2018). Estimating the variance for heterogeneity in arm-based network meta-analysis. Pharmaceutical Statistics 17, 264-77.

Williams, E.R. (2017). Alpha-Designs. Wiley StatsRef: Statistics Reference Online.

Piepho, H.P. and Williams, E.R. (2016). Augmented row-column designs for a small number of checks. Agronomy Journal, 108, 2256-62.

Freeman, G.H. and Williams, E.R. (2016). Row and column designs. Wiley StatsRef: Statistics Reference Online.

Piepho, H.P., Williams, E. R. and Michel, V. (2016). Nonresolvable Row-Column Designs with an Even Distribution of Treatment Replications. Journal of Agric., Biol. and Environ. Statist., 21, 227-242.

Piepho, H.P., Williams, E.R. and Michel, V. (2015). Beyond Latin squares: A brief tour of row-column designs.  Agron. J. 107, 2263-2270.

Mӧhring, J., Williams, E.R. and Piepho, H.P. (2015). Inter-block information: to recover or not to recover it? Theor. and Appl. Genet. 128, 1541-54.

Kennedy, A., Spiers, J.P., Crowley, V., Williams, E.R. and Lithander, F.E. (2015). Postprandial adiponectin and gelatinase response to a high-fat versus an isoenergetic low-fat meal in lean, healthy men. Nutrition 31, 863-70.

Williams, E.R. and Piepho, H.P. (2015). Optimality and contrasts in block designs with unequal treatment replication. Austral. & N.Z. J. Statist. 57, 203-9.

Piepho, H.P., Mӧhring, J., Pflugfelder, M., Hermann, W. and Williams, E.R. (2015). Problems in parameter estimation for power and AR(1) models of spatial correlation in designed field experiments. Comm. Biom. and Crop Sci., 10, 3-16.

Piepho, H.P., Madden, L.V. and Williams, E.R. (2015). Multiplicative interaction in network meta-analysis. Statistics in Medicine, 34, 582-94.

Williams, E.R. and Piepho, H.P. (2014). An evaluation of super-valid restricted randomization. J. Agric., Biol. and Environ. Statist., 19 , 470-478.

Williams, E. R., John, J.A. and Whitaker, D. (2014). Construction of more flexible and efficient p-rep designs. Australian and New Zealand Journal of Statistics, 56, 89-96.

Chen, Y., Williams, E.R. and Kirk, M. (2014). Risk factors for acute respiratory infection in the Australian community. PLoS ONE 9 : e101440.

Briceno, V., Harris-Pascal, D., Nicotra, A. B., Williams, E. R. and Ball, M. C. (2014). Variation in snow cover drives differences in frost resistance in seedlings of the alpine herb Aciphylla glacialis. Environmental and Experimental Botany, 106,174-181.

Sabastian, G., Kanowski, P., Race, D., Williams, E. and Roshetko, J.M. (2014). Household and farm attributes affecting adoption of smallholder timber management practices by tree growers in Gunungkidul region, Indonesia. Agroforestry Systems, 88, 257-268.

Mӧhring, J., Williams, E.R. and Piepho, H.P. (2014). Efficiency of augmented p-rep designs in multi-environmental trials. Theoretical and Applied Genetics, 127, 1049-1060.

Williams, E.R. and Piepho, H.P. (2013). A comparison of spatial designs for field variety trials. Australian & New Zealand Journal of Statistics, 53, 253-258.

Piepho, H.P., Mӧhring, J. and Williams, E.R. (2013). Why Randomize Agricultural Experiments? Journal of Agronomy and Crop Science, 199, 374-383.

Piepho, H.P., Williams, E.R. and Ogutu, J.O. (2013). A two-stage approach to recovery of inter-block information and shrinkage of block effect estimates. Communications in Biometry and Crop Science, 8, 10-22.

Hoyle, G., Vern, S., Steadman, K., Gook, R., Mcauliffe, J., Williams, E. and Nicotra, A. (2013). Soil warming increases diversity but decreases germination from an alpine soil seed bank. Global Change Biology, 16, 1549-1561.

Piepho, H.P., Williams, E.R. and Madden, L.V. (2012). The use of two-way linear mixed models in multi-treatment meta-analysis. Biometrics, 68, 1269-1277.

Williams, E.R. (2011). Computer-Assisted Statistics Textbooks - Experiments in Agriculture and Biology by Doug Stirling. Australian and New Zealand Journal of Statistics, 53, 483-494.

Forde, C.G., Cox, A., Williams, E.R. and Boss, P.K. (2011). Associations between the Sensory Attributes and Volatile Composition of Cabernet Sauvignon Wines and the Volatile Composition of the Grapes Used for Their Production. Journal of Agriculture and Food Chemistry, 59, 2573-2583.

Williams, E.R., Piepho, H.P. and Whitaker, D. (2011). Augmented p-rep designs. Biometrical Journal, 53, 19-27.

Piepho, H.P. and Williams, E.R. (2010). Linear variance models for plant breeding trials.  Plant Breeding 129, 1-8.

Piepho, H.P., Richter, C. and Williams, E.R. (2008). Nearest neighbour adjustment and linear variance models in plant breeding trials. Biom. J. 50, 164-89.

Bailey, R.A. and Williams, E.R. (2007). Optimal nested row-column designs with specified components.  Biometrika 94, 459-68.

Williams, E.R. and John, J.A. (2007).  Construction of crossover designs with correlated errors.  Austral. & N.Z. J. Statist. 49, 61-8.

Williams, E.R., Gunn, B.V.W., Solomon, D.J. and Doran, J.C. (2007).  Germination testing of stored E. camaldulensis seed.  Seed Science and Technology 35, 1-8.

Forde, C.G., Williams, E.R. and O'Riordan, J. (2007). Use of multi-stratum design and analysis in a sensory trial.  Food Quality and Preference 18, 614-8.

Nguyen, N.K. and Williams, E.R. (2006).  Experimental designs for 2-colour cDNA microarray experiments.  Applied Stochastic Models in Business and Industry 22, 631-8.

Doran, J.C., Williams, E.R., Baker, G.R. and Southwell, I.A.  (2006). Genetic gains in oil yields after nine years of breeding Melaleuca alternifolia (Myrtaceae).  Austral. J. Exp. Agric. 46, 1521-7.

Piepho, H.P. and Williams, E.R. (2006).  A comparison of experimental designs for selection in breeding trials with nested treatment structure. Theor. Appl. Genet. 113, 1505-13.

Piepho, H.P., Williams, E.R. and Fleck, M.  (2006). A note on the analysis of designed experiments with complex treatment structure.  HortScience 41, 446-52.

Williams, E.R., John, J.A. and Whitaker, D. (2006). Construction of resolvable spatial row-column designs. Biometrics 62, 103-8.