title: Naive Bayes for text classification with unbalanced classes

authors: Frank, Eibe

subjects: Science & Technology

abstract: Multinomial naive Bayes (MNB) is a popular method for document classification due to its computational efficiency and relatively good predictive performance. It has recently been established that predictive performance can be improved further by appropriate data transformations [1,2]. In this paper, we present another transformation that is designed to combat a potential problem with the application of MNB to unbalanced datasets. We propose an appropriate correction by adjusting attribute priors. This correction can be implemented as another data normalization step, and we show that it can significantly improve the area under the ROC curve. We also show that the modified version of MNB is very closely related to the simple centroid-based classifier and compare the two methods empirically.

text: Naive Bayes for text classification with unbalanced classes Multinomial naive Bayes (MNB) is a popular method for document classification due to its computational efficiency and relatively good predictive performance. It has recently been established that predictive performance can be improved further by appropriate data transformations [1,2]. In this paper, we present another transformation that is designed to combat a potential problem with the application of MNB to unbalanced datasets. We propose an appropriate correction by adjusting attribute priors. This correction can be implemented as another data normalization step, and we show that it can significantly improve the area under the ROC curve. We also show that the modified version of MNB is very closely related to the simple centroid-based classifier and compare the two methods empirically.

year: 2006-01-01

title: Youth sport in Trinidad and Tobago: Extending the possibilities and pathways for post-secondary school participation

authors: Lawrence-Ince, Karen

subjects: youth

abstract: Sport in Trinidad and Tobago (T&T) emerged out of centuries of occupation by different colonisers becoming more entrenched through the influences of the British. Continued but intermittent successes at the international level have led to increasing attention being directed to youth sport development within recent times. Whilst this has been unfolding at the national level, schools have been utilising resources within their command to keep youth involved in sport.  
This study primarily focused on youth sport practices in the senior comprehensive schools (SCS), a school type that was created and continuously reconfigured to meet the changing demands of education. In spite of a series of transitions, sport arose and persisted within these institutions carrying greater and greater significance as time elapsed. Whereas the SCS contributed to youth sport engagement at schools, community sport clubs and their respective National Governing Bodies (NGBs) working within the framework of a new service company, The Sport Company of Trinidad and Tobago (SPORTT), which operated under the aegis of the Ministry of Sport (MOS), provided additional opportunities for sport engagement. Efforts at these two levels however, appeared not to have produced maximum or prolonged benefits. Attrition rates in youth sport engagement at both school and community levels appeared to be sufficiently high, especially after students completed secondary schooling.   
The study therefore reports on research that investigated sport provision for youth in T&T, and specifically addressed coherence in provision across school, club, community and representative contexts. It followed the qualitative tradition and utilised an interpretative approach that bore a critical edge. Data was generated from investigations in three regional SCS school sites, and from participants in their homes and work places. Data collection involved conducting interviews with sport students past and present, as well as teachers, principals and professionals in the field of physical education and sport, and the collection of documents from the different sites. Analysis utilised a thematic approach within an iterative process.  
Findings revealed notable tensions and fragmentation in provision, particularly relating to (i) NGBs’ continued focus on elite development to the detriment of mass participation and capacity building; (ii) a relative lack of support in the community (with the exception of cricket); and (iii) pedagogical experiences and opportunities for young people within and beyond school characterised by disconnections. Discussion focuses on insights arising from an engagement with data and literature on education and sport policy, youth sport practices and physical education and sport pedagogy internationally. Recommendations arising from the research draw attention to actions needed to achieve coherence in sport provision for young people with a view to maximising pathways for sustained participation at all levels.

text: Youth sport in Trinidad and Tobago: Extending the possibilities and pathways for post-secondary school participation Sport in Trinidad and Tobago (T&T) emerged out of centuries of occupation by different colonisers becoming more entrenched through the influences of the British. Continued but intermittent successes at the international level have led to increasing attention being directed to youth sport development within recent times. Whilst this has been unfolding at the national level, schools have been utilising resources within their command to keep youth involved in sport.  
This study primarily focused on youth sport practices in the senior comprehensive schools (SCS), a school type that was created and continuously reconfigured to meet the changing demands of education. In spite of a series of transitions, sport arose and persisted within these institutions carrying greater and greater significance as time elapsed. Whereas the SCS contributed to youth sport engagement at schools, community sport clubs and their respective National Governing Bodies (NGBs) working within the framework of a new service company, The Sport Company of Trinidad and Tobago (SPORTT), which operated under the aegis of the Ministry of Sport (MOS), provided additional opportunities for sport engagement. Efforts at these two levels however, appeared not to have produced maximum or prolonged benefits. Attrition rates in youth sport engagement at both school and community levels appeared to be sufficiently high, especially after students completed secondary schooling.   
The study therefore reports on research that investigated sport provision for youth in T&T, and specifically addressed coherence in provision across school, club, community and representative contexts. It followed the qualitative tradition and utilised an interpretative approach that bore a critical edge. Data was generated from investigations in three regional SCS school sites, and from participants in their homes and work places. Data collection involved conducting interviews with sport students past and present, as well as teachers, principals and professionals in the field of physical education and sport, and the collection of documents from the different sites. Analysis utilised a thematic approach within an iterative process.  
Findings revealed notable tensions and fragmentation in provision, particularly relating to (i) NGBs’ continued focus on elite development to the detriment of mass participation and capacity building; (ii) a relative lack of support in the community (with the exception of cricket); and (iii) pedagogical experiences and opportunities for young people within and beyond school characterised by disconnections. Discussion focuses on insights arising from an engagement with data and literature on education and sport policy, youth sport practices and physical education and sport pedagogy internationally. Recommendations arising from the research draw attention to actions needed to achieve coherence in sport provision for young people with a view to maximising pathways for sustained participation at all levels.

year: 2016

title: Ki te kapu o takau ringa - In the Hollow of my Hand: Wānanga based Photographic Approaches to Place Representation

authors: Hill, Rodrigo

abstract: Ka matakitaki iho au ki te riu o Waikato
 Ano nei hei kapo kau ake maaku; 
Ki te kapu o taku ringa, 
“I look down on the valley of Waikato, 
As though to hold it  
In the hollow of my hand.
 The words above are from Māori King Tawhiao’s maioha (song poem), a representation of his love for his homelands of the Waikato and the region known today as the King Country. Now imagine a large-scale photograph: a close-up of cupped hands, holding an object carefully. The phrase above informs Professor Tom Roa and Dr. Rodrigo Hill’s current research project titled ‘Te Nehenehenui - The Ancient Enduring Beauty in the Great Forest of the King Country’. With this project still in its early stages the research team will present early and ongoing creative practice developments, discussions and ideas about photography practice, wānanga, and place representation. The project promotes the use of wānanga (forums and meetings of focus groups through which knowledge - mātauranga - is discussed and passed on) and other reflective practices, engaging with and led by mana whenua (guardians of the land) providing a thread which will guide the construction of the photographic images. The research fuses wānanga, that is Mātauranga Māori (Māori Knowledge), and photography practice in novel ways, aiming to move away and challenge core photographic conventions and Eurocentric modes of place representation. Roa and Hill understand wānanga as a fluid practice of engagement which can be with mana whenua or with the taiao - the environment - either by itself or with the mana whenua. This is the essence of Kaupapa Māori Research.

text: Ki te kapu o takau ringa - In the Hollow of my Hand: Wānanga based Photographic Approaches to Place Representation Ka matakitaki iho au ki te riu o Waikato
 Ano nei hei kapo kau ake maaku; 
Ki te kapu o taku ringa, 
“I look down on the valley of Waikato, 
As though to hold it  
In the hollow of my hand.
 The words above are from Māori King Tawhiao’s maioha (song poem), a representation of his love for his homelands of the Waikato and the region known today as the King Country. Now imagine a large-scale photograph: a close-up of cupped hands, holding an object carefully. The phrase above informs Professor Tom Roa and Dr. Rodrigo Hill’s current research project titled ‘Te Nehenehenui - The Ancient Enduring Beauty in the Great Forest of the King Country’. With this project still in its early stages the research team will present early and ongoing creative practice developments, discussions and ideas about photography practice, wānanga, and place representation. The project promotes the use of wānanga (forums and meetings of focus groups through which knowledge - mātauranga - is discussed and passed on) and other reflective practices, engaging with and led by mana whenua (guardians of the land) providing a thread which will guide the construction of the photographic images. The research fuses wānanga, that is Mātauranga Māori (Māori Knowledge), and photography practice in novel ways, aiming to move away and challenge core photographic conventions and Eurocentric modes of place representation. Roa and Hill understand wānanga as a fluid practice of engagement which can be with mana whenua or with the taiao - the environment - either by itself or with the mana whenua. This is the essence of Kaupapa Māori Research.

year: 2023-10-25