Learning analytics as a tool for exploring student learning patterns

Learning analytics can provide a statistical insight into the learning behaviours of students through the utilisation of datasets retrieved from online learning systems (OLS). These datasets are often large and contain mixed data types, potentially making both collation and analysis of the data complex. This research uses demographic, assessment and OLS data from a large undergrad- uate service course in statistics, taught at an Australian university. It provides an exemplar of how the application of learning analytics might be performed, using the R statistical package to implement multivariate statistical analyses. The research focuses on both the collection and preparation of educational data for analysis, and the application of both basic and multivariate statistical methodologies (cluster analysis and principal components analysis) to identify relationships between di�erent sources of data. It was found that the data collation process is time- and resource-intensive, but valuable as the integra- tion of di�erent data sources allows a deeper insight into the nature of student interaction within a course. Both cluster analysis and principal components analysis were found to provide useful interpretations of the data. The ma- jor relationships identi�ed include: external (online) students achieve higher grades than on-campus students; external students access OLS resources more frequently than on-campus students; students obtain lower grades in the invig- ilated examination than the open assignments; and students who do not access the OLS resources tend to perform poorer on course assessments. Suggestions for potential interventions with the aim of improving the academic perfor- mance of students based on these trends included making early contact with students who are not accessing course resources, and introducing an additional invigilated assessment item to the course assessment structure

Sowing summer grain crops early in late winter or spring: Effects on root growth, water use, and yield

CONTEXT. Drought and extreme heat at flowering are common stresses limiting the yield of summer crops. Adaptation to these stresses could be increased by sowing summer crops early in late winter or spring, to avoid the overlap with critical crop stages around flowering. Though little is known about the effects of cold weather on root growth, water use and final grain yield in sorghum. OBJECTIVE. To research the effects of cold conditions in early sowing sorghum on crop and root growth and function (i.e., water use), and final grain yield. METHODS. Two years of field experiments were conducted in the Darling and Eastern Downs region of Qld, Australia. Each trial consisted of three times of sowing (late winter, spring, and summer), two levels of irrigation (i.e., rainfed and supplementary irrigated), four plant population densities (3, 6, 9 and 12 pl m⁻²), and six commercial sorghum hybrids. Roots and shoots were sampled at the flag leaf stage on three times of sowing, two levels of irrigation, and three replications, for a single hybrid and a single plant population density (9pl m⁻²). Crop water use and functional root traits were derived from consecutive electromagnetic induction (EMI) surveys around flowering. At maturity crop biomass, yield and yield components were determined across all treatments. RESULTS. The combinations of seasons, times of sowing and levels of irrigation created large variations in growth conditions that affected the growth and production of the crops. Early sowing increased yield by transferring water use from vegetative to reproductive stages increasing water use efficiency (kg mm⁻¹ available water). The larger yields in the early and spring sown crops were associated to larger grain numbers, particularly in tillers. Cold temperatures in the early sowing times tended to produce smaller crops with smaller rooting systems, smaller root-to-shoot ratios, and larger average root diameters. Total root length and root length density increased with increasing pre-flowering mean air temperatures up to 20°C. Linear relationships were observed between an EMI derived index of root activity and the empirically determined values of root length density (cm cm⁻³) at flowering. CONCLUSIONS. Sowing sorghum, a summer crop, early in late winter or spring transferred water use from vegetative stages to flowering and post-flowering stages increasing crop water use efficiency. The higher grain numbers in early sown crops were related to higher grain numbers in tillers. Root length and root length density were reduced by pre-flowering mean temperatures lower than 20°C, indicating a need to increase cold tolerance for early sowing. The EMI derived index of root activity has potential in the development of high throughput root phenotyping applications

Wheat photosystem II heat tolerance: evidence for genotype‐by‐environment interactions

High temperature stress inhibits photosynthesis and threatens wheat production. One measure of photosynthetic heat tolerance is Tcrit – the critical temperature at which incipient damage to photosystem II (PSII) occurs. This trait could be improved in wheat by exploiting genetic variation and genotype-by-environment interactions (GEI). Flag leaf Tcrit of 54 wheat genotypes was evaluated in 12 thermal environments over 3 years in Australia, and analysed using linear mixed models to assess GEI effects. Nine of the 12 environments had significant genetic effects and highly variable broad-sense heritability (H2 ranged from 0.15 to 0.75). Tcrit GEI was variable, with 55.6% of the genetic variance across environments accounted for by the factor analytic model. Mean daily growth temperature in the month preceding anthesis was the most influential environmental driver of Tcrit GEI, suggesting biochemical, physiological and structural adjustments to temperature requiring different durations to manifest. These changes help protect or repair PSII upon exposure to heat stress, and may improve carbon assimilation under high temperature. To support breeding efforts to improve wheat performance under high temperature, we identified genotypes superior to commercial cultivars commonly grown by farmers, and demonstrated potential for developing genotypes with greater photosynthetic heat tolerance

Adapting to heat stress by sowing summer grain crops early in late winter: Sorghum root growth, water use, and yield

CONTEXT Drought and extreme heat at flowering are common stresses limiting the yield of summer crops, which are likely to intensify and become more frequent as projected under climate change.OBJECTIVE This study explores the idea that adaptation to these stresses could be increased by sowing summer crops early in late winter or spring, to avoid the overlap with critical crop stages around flowering. Here we report on the impacts of early sowing i.e., in late winter and spring on sorghum crop and root growth and function (i.e., water use), and final grain yield.METHODS Two seasons of on-farm genotype (G) by environment (E) by management (M) sorghum experimentation were conducted in the Darling Downs region of Queensland, Australia. Each trial consisted of a factorial combination of three times of sowing (TOS, referred to as late winter, spring, and summer), two levels of irrigation, four plant populations, and six commercial genotypes. Treatments were replicated three times. Crop roots and shoot were sampled at the flag leaf stage for each TOS. Crop water use across the growing season was monitored using time-lapse electromagnetic induction (EMI) surveys. EMI was also used to calculate a root activity factor. Final grain yield and yield components were determined at maturity.RESULTS Results showed that TOS, irrigation levels, and their interactions significantly influenced crop root and shoot traits, water use, and yield, though results were not always consistent across seasons. In the first season which was dry and had large temperature contrasts between TOS, crop growth in the early sown crops was primarily limited by temperature. In contrast, the second season was much warmer and crop growth was instead primarily limited by water availability. Cold air and soil temperatures in the early sowing dates i.e., late winter and spring during the first season, lead to smaller crops with smaller rooting systems and root-to-shoot ratios, and roots having a larger average root diameter. In general terms, root length and root length density responded positively to increasing pre-flowering mean air temperatures ranging between 16 and 20°C, while root average diameters were larger below 19 °C or above 21°C. Early sowing advanced flowering and therefore decreased the risk of extreme heat during the critical stages around flowering and affected water use before and after flowering. The root activity factor was directly related to the crop root length density. The early sown crops increased yield by transferring water use from vegetative to reproductive stages. The larger yield of the early sown crop was associated with larger grain numbers, particularly for the tillers, and a larger water use efficiency. As expected, irrigated and summer-sown crops exhibited lowest water use efficiency. The early-sown crops left more water in the soil profile at maturity, particularly under irrigated conditions and with small plant populations.CONCLUSIONS We conclude that early sown sorghum is a potential option to increase crop adaptation to hotter and drier environments. Here we propose that in the race to increase crop adaptation to heat stresses, plant breeding efforts should consider cold tolerance traits during crop germination, emergence, and early vegetative stages so that sorghum sowing windows could be significantly advanced.Competing Interest StatementThe authors have declared no competing interest