title: Is the Landing Error Scoring System Reliable and Valid? A Systematic Review

authors: Hanzlíková, Ivana

subjects: Science & Technology

abstract: Context: The Landing Error Scoring System (LESS) is a clinical tool often used in research and practice to identify athletes presenting high injury-risk biomechanical patterns during a jump-landing task. Objective: To systematically review the literature addressing the psychometric properties of the LESS. Data Sources: Three electronic databases (PubMed, Web of Science, and Scopus) were searched on March 28, 2018, using the term “Landing Error Scoring System.” Study Selection: All studies using the LESS as main outcome measure and addressing its reliability, validity against motion capture system, and predictive validity were included. Original English-language studies published in peer-reviewed journals were reviewed. Studies using modified versions of the LESS were excluded. Study Design: Systematic literature review. Level of Evidence: Level 4. Data Extraction: Study design, population, LESS testing procedures, LESS scores, statistical analysis, and main results were extracted from studies using a standardized template. Results: Ten studies met inclusion criteria and were appraised using Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies. The overall LESS score demonstrated good-to-excellent intrarater (intraclass correlation coefficient [ICC], 0.82-0.99), interrater (ICC, 0.83-0.92), and intersession reliability (ICC, 0.81). The validity of the overall LESS score against 3-dimensional jump-landing biomechanics was good when individuals were divided into 4 quartiles based on LESS scores. The validity of individual LESS items versus 3-dimensional motion capture data was moderate-to-excellent for most of the items addressing key risk factors for anterior cruciate ligament (ACL) injury. The predictive value of the LESS for ACL and other noncontact lower-extremity injuries remains uncertain based on the current scientific evidence. Conclusion: The LESS is a reliable screening tool. However, further work is needed to improve the LESS validity against motion capture system and confirm its predictive validity for ACL and other noncontact lower-extremity injuries.

text: Is the Landing Error Scoring System Reliable and Valid? A Systematic Review Context: The Landing Error Scoring System (LESS) is a clinical tool often used in research and practice to identify athletes presenting high injury-risk biomechanical patterns during a jump-landing task. Objective: To systematically review the literature addressing the psychometric properties of the LESS. Data Sources: Three electronic databases (PubMed, Web of Science, and Scopus) were searched on March 28, 2018, using the term “Landing Error Scoring System.” Study Selection: All studies using the LESS as main outcome measure and addressing its reliability, validity against motion capture system, and predictive validity were included. Original English-language studies published in peer-reviewed journals were reviewed. Studies using modified versions of the LESS were excluded. Study Design: Systematic literature review. Level of Evidence: Level 4. Data Extraction: Study design, population, LESS testing procedures, LESS scores, statistical analysis, and main results were extracted from studies using a standardized template. Results: Ten studies met inclusion criteria and were appraised using Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies. The overall LESS score demonstrated good-to-excellent intrarater (intraclass correlation coefficient [ICC], 0.82-0.99), interrater (ICC, 0.83-0.92), and intersession reliability (ICC, 0.81). The validity of the overall LESS score against 3-dimensional jump-landing biomechanics was good when individuals were divided into 4 quartiles based on LESS scores. The validity of individual LESS items versus 3-dimensional motion capture data was moderate-to-excellent for most of the items addressing key risk factors for anterior cruciate ligament (ACL) injury. The predictive value of the LESS for ACL and other noncontact lower-extremity injuries remains uncertain based on the current scientific evidence. Conclusion: The LESS is a reliable screening tool. However, further work is needed to improve the LESS validity against motion capture system and confirm its predictive validity for ACL and other noncontact lower-extremity injuries.

year: 2020-01-21

title: Better Self-training for Image Classification Through Self-supervision

authors: Sahito, Attaullah

subjects: Science & Technology

abstract: Self-training is a simple semi-supervised learning approach: Unlabelled examples that attract high-confidence predictions are labelled with their predictions and added to the training set, with this process being repeated multiple times. Recently, self-supervision—learning without manual supervision by solving an automatically-generated pretext task—has gained prominence in deep learning. This paper investigates three different ways of incorporating self-supervision into self-training to improve accuracy in image classification: self-supervision as pretraining only, self-supervision performed exclusively in the first iteration of self-training, and self-supervision added to every iteration of self-training. Empirical results on the SVHN, CIFAR-10, and PlantVillage datasets, using both training from scratch, and Imagenet-pretrained weights, show that applying self-supervision only in the first iteration of self-training can greatly improve accuracy, for a modest increase in computation time.

text: Better Self-training for Image Classification Through Self-supervision Self-training is a simple semi-supervised learning approach: Unlabelled examples that attract high-confidence predictions are labelled with their predictions and added to the training set, with this process being repeated multiple times. Recently, self-supervision—learning without manual supervision by solving an automatically-generated pretext task—has gained prominence in deep learning. This paper investigates three different ways of incorporating self-supervision into self-training to improve accuracy in image classification: self-supervision as pretraining only, self-supervision performed exclusively in the first iteration of self-training, and self-supervision added to every iteration of self-training. Empirical results on the SVHN, CIFAR-10, and PlantVillage datasets, using both training from scratch, and Imagenet-pretrained weights, show that applying self-supervision only in the first iteration of self-training can greatly improve accuracy, for a modest increase in computation time.

year: 2022-01-01

title: The Price of Mauri: Exploring the validity of Welfare Economics when seeking to measure Mātauranga Māori

authors: Awatere, Shaun

subjects: welfare economics

abstract: Since the 1980s New Zealand has pursued neo-classical or market-based policies with a particular fervour. Market-based options are seen by resource management decision makers as essential frameworks for efficiently allocating resources, an approach that continues to support the view of the inherent dominance of Western knowledge. This is particularly concerning, given that Māori (the indigenous people of New Zealand), have an important role to play in New Zealand resource management and perceive their own knowledge systems have been marginalised. The primary goal of this thesis is to explore the validity of welfare economics when seeking to measure quantitatively Mātauranga Māori or Māori views of the environment through the contingent valuation method. A contingent valuation study is carried out using three separate samples drawn from the general Māori population in Auckland city, a hāpu/sub-tribe indigenous to the Auckland isthmus, and drivers of motor vehicles in Auckland city. Data collection modes include a postal survey and face-to-face interviews. This thesis challenges the validity of political-legal ethnicity constructs to measure Mātauranga Māori. The search for a central tendency will lead to biased, misleading and inaccurate results. The thesis also challenges the validity of contingent valuation to produce true economic measures and to measure and identify Mātauranga Māori. Despite advances in analytical techniques, economic efficiency measures are always deficient, given the difficulty of capturing and anticipating all impacts and valuing them appropriately. Mātauranga Māori is derived from a Māori epistemology and should be considered or analysed with primary reference to this body of knowledge. Economic analysis is only one important cog in the machinery of resource management policy. Given that an economist's contribution to local and regional resource management is most valuable when focusing on the  economic efficiency  of the proposed resource allocation, it is appropriate that other perspectives such as Mātauranga Māori be considered.

text: The Price of Mauri: Exploring the validity of Welfare Economics when seeking to measure Mātauranga Māori Since the 1980s New Zealand has pursued neo-classical or market-based policies with a particular fervour. Market-based options are seen by resource management decision makers as essential frameworks for efficiently allocating resources, an approach that continues to support the view of the inherent dominance of Western knowledge. This is particularly concerning, given that Māori (the indigenous people of New Zealand), have an important role to play in New Zealand resource management and perceive their own knowledge systems have been marginalised. The primary goal of this thesis is to explore the validity of welfare economics when seeking to measure quantitatively Mātauranga Māori or Māori views of the environment through the contingent valuation method. A contingent valuation study is carried out using three separate samples drawn from the general Māori population in Auckland city, a hāpu/sub-tribe indigenous to the Auckland isthmus, and drivers of motor vehicles in Auckland city. Data collection modes include a postal survey and face-to-face interviews. This thesis challenges the validity of political-legal ethnicity constructs to measure Mātauranga Māori. The search for a central tendency will lead to biased, misleading and inaccurate results. The thesis also challenges the validity of contingent valuation to produce true economic measures and to measure and identify Mātauranga Māori. Despite advances in analytical techniques, economic efficiency measures are always deficient, given the difficulty of capturing and anticipating all impacts and valuing them appropriately. Mātauranga Māori is derived from a Māori epistemology and should be considered or analysed with primary reference to this body of knowledge. Economic analysis is only one important cog in the machinery of resource management policy. Given that an economist's contribution to local and regional resource management is most valuable when focusing on the  economic efficiency  of the proposed resource allocation, it is appropriate that other perspectives such as Mātauranga Māori be considered.

year: 2008