Peter Dunn | University of the Sunshine Coast (original) (raw)

Papers by Peter Dunn

International Journal of Mathematical Education in Science and Technology, Oct 7, 2021

This article discusses the development of an interactive online textbook for undergraduate teachi... more This article discusses the development of an interactive online textbook for undergraduate teaching, in response to moving teaching online due to COVID-19. The development took place initially for a university with less than 5% of students studying online in 2019. The online textbook was incorporated into a large, diverse, multidisciplinary and predominantly first-year undergraduate research design and statistics course. Digital tools were embedded into the textbook to facilitate student engagement in lieu of face-to-face contact, including online crosswords for low-level statistical literacy, drop-and-drag activities, screencasts, exercises, animations, and videos. The textbook was prepared in markdown format. This approach allows for instant updating of material and provides focussed URLs that educators can use to point students directly to specific learning outcomes. Despite the textbook being developed in response to restricted teaching conditions, it has provided a cost-effective resource, targeted at teaching research design and basic statistics concepts, interpretation, and communication. Having returned to face-to-face teaching, the text is now fully integrated into the course. Importantly, the online textbook is freely available for other educators to use, either in its existing form, or by forking (on Github) the textbook sources to create a bespoke online textbook for other courses.

Environmental Science and Pollution Research, Sep 1, 2021

Biochar compound fertilisers (BCFs) are an emerging technology that combine biochar with nutrient... more Biochar compound fertilisers (BCFs) are an emerging technology that combine biochar with nutrients, clays and minerals and can be formulated to address specific issues in soil-plant systems. However, knowledge of BCF performance over consecutive crops and without re-application is limited. This study aims to assess the residual effect of organic BCFs soil-plant nutrient cycling 2 years after application and without additional fertiliser inputs. We applied BCFs and biochar with organic fertiliser amendments and established a crop of ginger and a second crop of turmeric (Curcuma longa) without re-application or additional fertilisation. All treatment formulations included bamboo-biochar and organic fertiliser amendments; however, two novel BCFs were formulated to promote agronomic response in an intensive cropping system. We report here on the effect of treatments on soil and plant macronutrient and micronutrient cycling and turmeric growth, biomass and yield at harvest. Both BCFs (enriched (10 t ha−1) and organo-mineral biochar (8.6 t ha−1) increased foliar K (+155% and +120%) and decreased foliar Mg (−20% and −19%) concentration compared with all other treatments, suggesting antagonism between K and Mg. Plants were limited for K, P and B at harvest but not N, Ca or Mg. Foliar K was dependent on the biochar formulation rather than the rate of application. Biochar-clay aggregates increased K retention and cycling in the soil solution 2 years after application. Clay blended BCFs reduced K limitation in turmeric compared to biochar co-applied with organic amendments, suggesting these blends can be used to manage organic K nutrition. All formulations and rates of biochar increased leaf biomass and shoot-to-root ratio. Novel BCFs should be considered as an alternative to co-applying biochar with organic fertiliser amendments to decrease application rates and increase economic feasibility for farmers. Applying BCFs without re-application or supplementary fertiliser did not provide sufficient K or P reserves in the second year for consecutive cropping. Therefore, supplementary fertilisation is recommended to avoid nutrient deficiency and reduced yield for consecutive organic rhizome crops.

STATISTICS EDUCATION RESEARCH JOURNAL

With the GAISE emphasis on prioritising concept development over mathematical calculation in stat... more With the GAISE emphasis on prioritising concept development over mathematical calculation in statistics education, statistical language has increasingly become the focus of research. Yet, there is a dearth of research investigating techniques to teach statistical language. To redress this gap, we introduced a group of statistics tutors to some cooperative learning techniques commonly used to teach language and concepts in other disciplines (Jigsaw and Think-Pair-Share). The twofold aim was to explore the tutors’ uptake of the techniques and how to improve their proficiency in implementing the techniques. The techniques were delivered experientially with tutors through a professional development session followed by implementation of the techniques in their tutorials. A semester-long exploratory case study was conducted using surveys, focus group sessions and shared self-reflection on a digital discussion board. From the tutors’ reported experience and feedback, areas for improvement ...

Research in Mathematics Education in Australasia 2016–2019, 2020

Reviewed in this chapter is the growing depth and variety of research being undertaken in the ter... more Reviewed in this chapter is the growing depth and variety of research being undertaken in the tertiary mathematics field. In particular, the scope of the research and issues being examined have been highlighted in sections:

Journal of Statistics Education, 2013

In this paper, we report a case study that illustrates the importance in interpreting the results... more In this paper, we report a case study that illustrates the importance in interpreting the results from statistical tests, and shows the difference between practical importance and statistical significance. This case study presents three sets of data concerning the performance of two brands of batteries. The data are easy to describe and understand, familiar to students, and allow a range of analyses, from simple to more complex. The data were the basis of a claim made in an advertisement, and this claim is reassessed using the data to show that the company undersold the performance of their batteries from a statistical point-of-view in one of the three tests. However, a challenge is how such a conclusion can be communicated to the public succinctly but correctly.

International Journal of Mathematical Education in Science and Technology, 2021

Journal of Soils and Sediments, 2021

Biochar can improve soil nutrient retention and alleviate salinity; however, use is not widesprea... more Biochar can improve soil nutrient retention and alleviate salinity; however, use is not widespread due to cost. Biochar is usually co-applied with a full-rate of supplementary fertiliser before planting. This study investigated co-application of bamboo biochar with organic fertiliser and amendments on nutrient cycling, plant growth, yield and commercial value of ginger. Four treatments were applied including no amendment, organic amendments and organic amendments co-applied with biochar at two applications rates of 10 t ha−1 and 30 t ha−1. Plant growth, biomass, foliar nutrient and water-extractable soil nutrients were examined. Co-applied high rate biochar increased available soil potassium (K) concentration (+ 89%) over 22 weeks and led to increased foliar K concentration (+ 25%) at harvest and after 30 weeks compared with organic amendments alone. Biochar high rate decreased soil sodium concentration (− 22%) over 22 weeks. Biochar high rate increased root mass fraction and plant height but decreased the number of stems, and therefore, did not increase aboveground biomass compared with all other treatments. In contrast, ginger rhizome yield, grade and commercial value were not affected by biochar treatments. Added biochar provided additional net K that improved foliar concentration late in the growing season following dissolution. The additional K supply then stimulated root growth and biomass re-allocation despite daily irrigation throughout the growing season. Therefore, we suggest biochar as a useful amendment to prevent nutrient loss and alleviate salinity for organic crops.

STATISTICS EDUCATION RESEARCH JOURNAL, 2016

Learning statistics requires learning the language of statistics. Statistics draws upon words fro... more Learning statistics requires learning the language of statistics. Statistics draws upon words from general English, mathematical English, discipline-specific English and words used primarily in statistics. This leads to many linguistic challenges in teaching statistics and the way in which the language is used in statistics creates an extra layer of challenge. This paper identifies several challenges in teaching statistics related to language. Some implications for the effective learning and teaching of statistics are raised and methods to help students overcome these linguistic challenges are suggested. First published May 2016 at Statistics Education Research Journal Archives

Remote Sensing, 2021

Hyperspectral image (HSI) analysis has the potential to estimate organic compounds in plants and ... more Hyperspectral image (HSI) analysis has the potential to estimate organic compounds in plants and foods. Curcumin is an important compound used to treat a range of medical conditions. Therefore, a method to rapidly determine rhizomes with high curcumin content on-farm would be of significant advantage for farmers. Curcumin content of rhizomes varies within, and between varieties but current chemical analysis methods are expensive and time consuming. This study compared curcumin in three turmeric (Curcuma longa) varieties and examined the potential for laboratory-based HSI to rapidly predict curcumin using the visible–near infrared (400–1000 nm) spectrum. Hyperspectral images (n = 152) of the fresh rhizome outer-skin and flesh were captured, using three local varieties (yellow, orange, and red). Distribution of curcuminoids and total curcumin was analysed. Partial least squares regression (PLSR) models were developed to predict total curcumin concentrations. Total curcumin and the pro...

Teaching Mathematics and its Applications: An International Journal of the IMA, 2019

Mathematics teachers are often keen to find ways of connecting mathematics with the real world. O... more Mathematics teachers are often keen to find ways of connecting mathematics with the real world. One way to do so is to teach mathematical modelling using real data. Mathematical models have two components: a model structure and parameters within that structure. Real data can be used in one of two ways for each component: (a) to validate what theory or context suggests or (b) to estimate from the data. It is crucial to understand the following: the implications of using data in these different ways, the differences between them, the implications for teaching and how this can influence students’ perceptions of the real-world relevance of mathematics. Inappropriately validating or estimating with data may unintentionally promote poor practice and (paradoxically) reinforce in students the incorrect idea that mathematics has no relevance to the real world. We recommend that teachers approach mathematical modelling through mathematizing the context. We suggest a framework to support teach...

The American Statistician, 2017

The six recommendations made by the Guidelines for Assessment and Instruction in Statistics Educa... more The six recommendations made by the Guidelines for Assessment and Instruction in Statistics Education (GAISE) committee were first communicated in 2005 and more formally in 2010. In this paper, 25 introductory statistics textbooks are examined to assess how well these textbooks have incorporated the three GAISE recommendations most relevant to implementation in textbooks (statistical literacy and thinking; use of real data; stress concepts over procedures). The implementation of another recommendation (using technology) is described but not

Journal of Statistical Software, 1999

Generalized linear models unite a wide variety of statistical models in a common theoretical fram... more Generalized linear models unite a wide variety of statistical models in a common theoretical framework. This paper discusses glmlab|software that enables such models to be tted in the popular mathematical package matlab. It provides a graphical user interface to the powerful matlab computational engine to produce a program that is easy to use but with many features, including o sets, prior weights and user-de ned distributions and link functions. matlab's graphical capacities are also utilized in providing a number of simple residual diagnostic plots.

International Journal of Climatology, 2014

Theoretical probability distributions of seasonal rainfall totals have potential applications in ... more Theoretical probability distributions of seasonal rainfall totals have potential applications in fitting models and generating synthetic data. One of the major challenges in fitting distributions for seasonal rainfall from countries like Australia is that the data differ significantly for various seasons across stations. The wet stations may possess strictly positive rainfall amounts only, whereas dry stations may observe seasons with no rainfall. Furthermore the data ranges from approximately symmetric to highly skewed. We explore fitting distributions from the Tweedie family of distributions to model seasonal rainfall. The Tweedie family of distributions includes continuous-symmetric (normal), continuous-skewed (gamma) and mixture-type (Poisson-gamma, P-G) distributions. This study analysed seasonal rainfall totals from 989 Australian stations with data for about 100 years. For various seasons, within the Tweedie family the P-G distributions were optimal for about 50% of stations, the gamma distributions were near-optimal for approximately 40% and the normal distributions were near-optimal elsewhere. Most of the stations where the gamma distributions are near-optimal are concentrated on the Australian coastline. The quantile-quantile (QQ) plots indicate that the models fit well to the seasonal rainfall totals of selected stations. Almost everywhere, various statistics of observed seasonal rainfall are within the empirical 95% confidence intervals of the respective statistics of simulated data using the Tweedie models. The model performs better in modelling extremely high rainfall events (95th percentiles) than the extremely low (5th percentiles) rainfall events. In addition, the P-G distribution within the Tweedie family models the probability of no rainfall and, for about 97% of stations, the observed probability of no rainfall is within the 95% confidence interval of the simulated probability of no rainfall. The ability of the Tweedie models to simulate the extreme rainfall amounts and the probability of no rainfall can be useful in drought monitoring and in water resources planning and management.

Precision Agriculture, 2006

Statistical tools are discussed for the analysis of data collected from tractor guidance systems.... more Statistical tools are discussed for the analysis of data collected from tractor guidance systems. The importance of both accuracy and precision is discussed, and statistical tools for analysis are considered which incorporate important features of the data. In particular, accuracy is modelled using a generalized least squares model incorporating autocorrelation, and precision using a gamma generalized linear model. The methods are applied to data collected during an experiment conducted with a Trimble receiver used with a Beeline tractor guidance system. Three different scenarios are considered, then compared: a tractor simulating ploughing a field; the tractor pulling a plough with the receivers on the tractor; the tractor pulling a plough with the Trimble receiver on the plough. The change in the precision and accuracy between the scenarios is discussed. Data was collected over repeated swaths for each scenario. After discussing specific statistical techniques for analysis of this type of data, the collected data are analysed; major conclusions are: the data collected from the Trimble receiver showed evidence of autocorrelation in the offsets; the implement recorded a variance about three times that recorded by the tractor.

Language Testing, 2011

This study investigated factors that could affect inter-examiner reliability in the pronunciation... more This study investigated factors that could affect inter-examiner reliability in the pronunciation assessment component of speaking tests. We hypothesized that the rating of pronunciation is susceptible to variation in assessment due to the amount of exposure examiners have to nonnative English accents. An inter-rater variability analysis was conducted on the English pronunciation ratings of three test candidate interlanguages: Chinese, Korean, and Indian English. Pronunciation was rated by 99 International English Language Testing System (IELTS) examiners across five geographically dispersed test centres. The examiners had either prolonged exposure, or no, or little exposure to the interlanguage of the candidates. A significant proportion of examiners rated pronunciation higher when they had prolonged exposure, and lower when they had no, or little, exposure to the candidates’ interlanguage. The location of the test centre also had a significant effect on the pronunciation rating, i...

Journal of Computational and Graphical Statistics, 1996

PuDlic reporting burden for this collection of information is estimated to average 1 hour per res... more PuDlic reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, qathering and maintaining the data needed and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of (his collection of information including suggestions for reducing this burden, to

International Journal of Climatology, 2011

Rainfall models are used to understand the effect of various climatological variables on rainfall... more Rainfall models are used to understand the effect of various climatological variables on rainfall amounts. The models also have potential uses in predicting and simulating rainfall. We use Tweedie generalized linear models to model monthly rainfall amounts and occurrence simultaneously with a set of predictors (sine term, cosine term, NINO 3.4, SOI and SOI phase). Models are fitted to the monthly rainfall data of 220 Australian stations with 4 stations as case studies. First, models with only sine and cosine terms (the base model) are fitted to model the cyclic pattern of rainfall data, and then one of the climatological variables is added each time in addition to the base model. On the basis of the BIC, the model with NINO 3.4 is preferred for most of the studied stations. Stations for which the model using the SOI is preferred appear in small clusters. Adding the climatological variables to the base model improves the fit of the model and makes substantial changes in the predicted...

International Journal of Climatology, 2004

Many statistical models exist for modelling precipitation. One difficulty is that two issues need... more Many statistical models exist for modelling precipitation. One difficulty is that two issues need to be addressed: the probability of precipitation occurring, and then the quantity of precipitation recorded. This paper considers a family of distributions for modelling the quantity of precipitation, including those observations in which exactly no precipitation is recorded. Two examples are then discussed showing the distributions model the precipitation patterns well. Copyright