title: Effect of footwear on Y-Balance Test performance & risk categorisation

authors: Beaven, Christopher Martyn

abstract: Introduction: The Y-Balance Test (YBT) assesses dynamic balance and screens for injury risk. However, there are inconsistent recommendations regarding footwear use during testing. Methods: Forty-two volunteers (26 females, 16 males) performed the YBT with their habitual athletic footwear and barefoot on both legs. In a single-legged stance, participants reached with the contralateral limb in the anterior, posteromedial, and posterolateral directions three times. Leg- length normalised composite scores (%) and anterior-reach differences (cm) were extracted and used to identify high-risk participants (i.e., anterior-reach difference ≥4 cm or composite score ≤94%). Results: Anterior, posteromedial, and anterior-reach difference measures were similar between conditions (P>0.05). Posterolateral (2.8±7.6 cm, P=0.001) and composite scores (93.4 vs 94.8%, P=0.018) were greater barefoot. The proportion of individuals at high-risk based on anterior- reach difference (odds ratio: 1.6, McNear test P =0.58) and composite scores (odds ratio: 2.2, P=0.21) was similar between conditions, although risk categorisation was inconsistent in 31 and 19% of cases, respectively. Discussion: Footwear altered the composite score such that the group average exceeded the high-risk threshold. While testing in athletic footwear may be more valid, researchers should be aware that risk categorisation is affected. Take home message: Care should be taken when comparing studies with different protocols.

text: Effect of footwear on Y-Balance Test performance & risk categorisation Introduction: The Y-Balance Test (YBT) assesses dynamic balance and screens for injury risk. However, there are inconsistent recommendations regarding footwear use during testing. Methods: Forty-two volunteers (26 females, 16 males) performed the YBT with their habitual athletic footwear and barefoot on both legs. In a single-legged stance, participants reached with the contralateral limb in the anterior, posteromedial, and posterolateral directions three times. Leg- length normalised composite scores (%) and anterior-reach differences (cm) were extracted and used to identify high-risk participants (i.e., anterior-reach difference ≥4 cm or composite score ≤94%). Results: Anterior, posteromedial, and anterior-reach difference measures were similar between conditions (P>0.05). Posterolateral (2.8±7.6 cm, P=0.001) and composite scores (93.4 vs 94.8%, P=0.018) were greater barefoot. The proportion of individuals at high-risk based on anterior- reach difference (odds ratio: 1.6, McNear test P =0.58) and composite scores (odds ratio: 2.2, P=0.21) was similar between conditions, although risk categorisation was inconsistent in 31 and 19% of cases, respectively. Discussion: Footwear altered the composite score such that the group average exceeded the high-risk threshold. While testing in athletic footwear may be more valid, researchers should be aware that risk categorisation is affected. Take home message: Care should be taken when comparing studies with different protocols.

year: 2018

title: A diversity-aware model for majority vote ensemble accuracy

authors: Lim, Nick Jin Sean

subjects: Science & Technology

abstract: Ensemble classifiers are a successful and popular approach for classification, and are frequently found to have better generalization performance than single models in practice. Although it is widely recognized that ‘diversity’ between ensemble members is important in achieving these performance gains, for classification ensembles it is not widely understood which diversity measures are most predictive of ensemble performance, nor how large an ensemble should be for a particular application. In this paper, we explore the predictive power of several common diversity measures and show – with extensive experiments – that contrary to earlier work that finds no clear link between these diversity measures (in isolation) and ensemble accuracy instead by using the ρ diversity measure of Sneath and Sokal as an estimator for the dispersion parameter of a Polya-Eggenberger distribution we can predict, independently of the choice of base classifier family, the accuracy of a majority vote classifier ensemble ridiculously well. We discuss our model and some implications of our findings – such as diversity-aware (non-greedy) pruning of a majority-voting ensemble.

text: A diversity-aware model for majority vote ensemble accuracy Ensemble classifiers are a successful and popular approach for classification, and are frequently found to have better generalization performance than single models in practice. Although it is widely recognized that ‘diversity’ between ensemble members is important in achieving these performance gains, for classification ensembles it is not widely understood which diversity measures are most predictive of ensemble performance, nor how large an ensemble should be for a particular application. In this paper, we explore the predictive power of several common diversity measures and show – with extensive experiments – that contrary to earlier work that finds no clear link between these diversity measures (in isolation) and ensemble accuracy instead by using the ρ diversity measure of Sneath and Sokal as an estimator for the dispersion parameter of a Polya-Eggenberger distribution we can predict, independently of the choice of base classifier family, the accuracy of a majority vote classifier ensemble ridiculously well. We discuss our model and some implications of our findings – such as diversity-aware (non-greedy) pruning of a majority-voting ensemble.

year: 2020

title: Challenges to psychology in Aotearoa

authors: Awatere-Huata, Donna

subjects: Maori

abstract: Maori people are putting up with a lot right now. If governments can transfer $20 billion in the past ten years for hand outs and write offs to Pakeha people who have endured little, then they can do a lot better than the $150 million they’ve transferred to our people that have endured so much for 150 years.  The big issue is still the Treaty, and the need to re-negotiate this nation’s management. The challenge is to design a political system that is based on Maori ways of doing things rather than Pakeha ways of doing things. To achieve this requires relinquishing colonial patterns of thinking and the certainty that pakeha people and their ways are superior to Maori. For psychologists the issue is their role in maintaining Pakeha economic and political power. It may well be that psychologists provide lousy value for money from the Maori point of view, but provide excellent value for money from the government’s point of view.

text: Challenges to psychology in Aotearoa Maori people are putting up with a lot right now. If governments can transfer $20 billion in the past ten years for hand outs and write offs to Pakeha people who have endured little, then they can do a lot better than the $150 million they’ve transferred to our people that have endured so much for 150 years.  The big issue is still the Treaty, and the need to re-negotiate this nation’s management. The challenge is to design a political system that is based on Maori ways of doing things rather than Pakeha ways of doing things. To achieve this requires relinquishing colonial patterns of thinking and the certainty that pakeha people and their ways are superior to Maori. For psychologists the issue is their role in maintaining Pakeha economic and political power. It may well be that psychologists provide lousy value for money from the Maori point of view, but provide excellent value for money from the government’s point of view.

year: 1993