title: Using a permutation test for attribute selection in decision trees

authors: Frank, Eibe

subjects: computer science

abstract: Most techniques for attribute selection in decision trees are biased towards attributes with many values, and several ad hoc solutions to this problem have appeared in the machine learning literature. Statistical tests for the existence of an association with a prespecified significance level provide a well-founded basis for addressing the problem. However, many statistical tests are computed from a chi-squared distribution, which is only a valid approximation to the actural distribution in the large-sample case-and this patently does not hold near the leaves of a decision tree. An exception is the class of permutation tests. We describe how permutation tests can be applied to this problem. We choose one such test for further exploration, and give a novel two-stage method for applying it to select attributes in a decision tree. Results on practical datasets compare favourably with other methods that also adopt a pre-pruning strategy.

text: Using a permutation test for attribute selection in decision trees Most techniques for attribute selection in decision trees are biased towards attributes with many values, and several ad hoc solutions to this problem have appeared in the machine learning literature. Statistical tests for the existence of an association with a prespecified significance level provide a well-founded basis for addressing the problem. However, many statistical tests are computed from a chi-squared distribution, which is only a valid approximation to the actural distribution in the large-sample case-and this patently does not hold near the leaves of a decision tree. An exception is the class of permutation tests. We describe how permutation tests can be applied to this problem. We choose one such test for further exploration, and give a novel two-stage method for applying it to select attributes in a decision tree. Results on practical datasets compare favourably with other methods that also adopt a pre-pruning strategy.

year: 1998

title: Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing

authors: Membery, Brent

subjects: Tattoos

abstract: This study aimed to examine the reasons why individuals in Aotearoa New Zealand tattoo their bodies and analyse the mechanism by which tattoo acts as a method of coping, self-healing and self-transformation for these individuals. Further this study aimed to investigate how tattoo allows individuals to re-write and transform their meaning of traumatic and/or stressful events into stories of empowerment, strength and survival. While tattoo has been explored for meaning and function in Aotearoa New Zealand, there was seen to be no empirically grounded research looking into how tattoo might serve as a therapeutic tool. 
	The study examined 427 survey respondents and eight interviewees across Aotearoa New Zealand. The participants ranged in age from 18 to 65-years-old and varied across multiple ethnicities. 
	This study combined quantitative and qualitative data collection methods in a two-phase project. Data collection phase one involved 427 participants respond to an online survey. This establised a baseline for cross-comparison of attitudes, backgrounds and life experiences. Data collection phase two involved eight semi-structured interviews to explore individual experiences and uncover the relationship between their tattoos and how it had helped them to cope/heal in some way. To analyse these interviews, thematic analysis was combined with phenomenological analysis.   
	The findings from this study suggest that there are multiple reasons (expression of self, aesthetic aspects, identity, passage of rights, remembrance/tributes and personal healing among others) why individuals chose to engage in the art form of tattooing. Findings also suggest that tattoo, directly relating to the mind/body continuum of stress/trauma can serve as a mechanism to enable individuals to re-script stressful/traumatic events, reinforce identity and self-acceptance, acknowledge past difficulties and turn them into positives and increase inner motivations and positive thinking which was seen to initiate healing and recovery. This suggests that tattoo serves as a powerful mechanism to aid in personal transformation, but also challenge previous meanings associated with the art form of tattoo.

text: Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing This study aimed to examine the reasons why individuals in Aotearoa New Zealand tattoo their bodies and analyse the mechanism by which tattoo acts as a method of coping, self-healing and self-transformation for these individuals. Further this study aimed to investigate how tattoo allows individuals to re-write and transform their meaning of traumatic and/or stressful events into stories of empowerment, strength and survival. While tattoo has been explored for meaning and function in Aotearoa New Zealand, there was seen to be no empirically grounded research looking into how tattoo might serve as a therapeutic tool. 
	The study examined 427 survey respondents and eight interviewees across Aotearoa New Zealand. The participants ranged in age from 18 to 65-years-old and varied across multiple ethnicities. 
	This study combined quantitative and qualitative data collection methods in a two-phase project. Data collection phase one involved 427 participants respond to an online survey. This establised a baseline for cross-comparison of attitudes, backgrounds and life experiences. Data collection phase two involved eight semi-structured interviews to explore individual experiences and uncover the relationship between their tattoos and how it had helped them to cope/heal in some way. To analyse these interviews, thematic analysis was combined with phenomenological analysis.   
	The findings from this study suggest that there are multiple reasons (expression of self, aesthetic aspects, identity, passage of rights, remembrance/tributes and personal healing among others) why individuals chose to engage in the art form of tattooing. Findings also suggest that tattoo, directly relating to the mind/body continuum of stress/trauma can serve as a mechanism to enable individuals to re-script stressful/traumatic events, reinforce identity and self-acceptance, acknowledge past difficulties and turn them into positives and increase inner motivations and positive thinking which was seen to initiate healing and recovery. This suggests that tattoo serves as a powerful mechanism to aid in personal transformation, but also challenge previous meanings associated with the art form of tattoo.

year: 2015

title: Indigenous knowledges in health policy in Aotearoa New Zealand and Saskatchewan Canada: A comparative study

authors: Green, Jane Alison

subjects: Indigenous

abstract: For more than two decades, components of Māori knowledges in the form of Māori words and concepts have been part of health policy in Aotearoa New Zealand. Health policy that engages Māori words and concepts resonates with Māori community values and aspirations and is thought to contribute to the revitalisation of Māori knowledges. Absent from the literature is an examination of this phenomenon; specifically, the socio-political factors that facilitate and limit the engagement of Māori knowledges with health policy. Of the four settler states, only in Aotearoa New Zealand are the knowledges of the Indigenous peoples engaged with health policy. In Saskatchewan, Canada, the First Nations and Métis peoples have engaged their knowledges with federal and provincially funded health programmes and services but not health policy. This study adopts a two-country comparative policy framework to investigate and theorise the historical and contemporary socio-political factors associated with the engagement of Indigenous knowledges in health policy in Aotearoa New Zealand and Saskatchewan, Canada. An adaption is made to the Kaupapa Māori approach so that the complexities of a two-country case study approach are addressed and engagement in health policy as a strategy for knowledge revitalisation is theorised. The study also takes a path less travelled which is to investigate the impact that engagement with health policy has upon the intangible or the ontological aspects of Māori knowledges. Māori describe their knowledges as comprised of tangible and intangible elements, both of which are important. Another adaption is made to the Kaupapa Māori theoretical approach which is to add speculative inquiry. The study argues that speculative inquiry in the form of contemplative, analytical, relational and viscerally aware practices are commonplace in Māori communities. Adding speculative inquiry to an already rich theoretical body that is Kaupapa Māori research provides an opening for other Kaupapa Māori researchers to expand non-empirical inquiry. The study concludes that government policies have had a decimating effect upon Māori, First Nations and Métis knowledges. Moreover, recent reports from commissions and inquiries indicate these knowledges and associated languages continue to decline for a number of reasons, including the impact of contemporary government policies. Health policy, this study asserts, is an uncertain site from which to revitalise Māori, First Nations and Métis knowledges.

text: Indigenous knowledges in health policy in Aotearoa New Zealand and Saskatchewan Canada: A comparative study For more than two decades, components of Māori knowledges in the form of Māori words and concepts have been part of health policy in Aotearoa New Zealand. Health policy that engages Māori words and concepts resonates with Māori community values and aspirations and is thought to contribute to the revitalisation of Māori knowledges. Absent from the literature is an examination of this phenomenon; specifically, the socio-political factors that facilitate and limit the engagement of Māori knowledges with health policy. Of the four settler states, only in Aotearoa New Zealand are the knowledges of the Indigenous peoples engaged with health policy. In Saskatchewan, Canada, the First Nations and Métis peoples have engaged their knowledges with federal and provincially funded health programmes and services but not health policy. This study adopts a two-country comparative policy framework to investigate and theorise the historical and contemporary socio-political factors associated with the engagement of Indigenous knowledges in health policy in Aotearoa New Zealand and Saskatchewan, Canada. An adaption is made to the Kaupapa Māori approach so that the complexities of a two-country case study approach are addressed and engagement in health policy as a strategy for knowledge revitalisation is theorised. The study also takes a path less travelled which is to investigate the impact that engagement with health policy has upon the intangible or the ontological aspects of Māori knowledges. Māori describe their knowledges as comprised of tangible and intangible elements, both of which are important. Another adaption is made to the Kaupapa Māori theoretical approach which is to add speculative inquiry. The study argues that speculative inquiry in the form of contemplative, analytical, relational and viscerally aware practices are commonplace in Māori communities. Adding speculative inquiry to an already rich theoretical body that is Kaupapa Māori research provides an opening for other Kaupapa Māori researchers to expand non-empirical inquiry. The study concludes that government policies have had a decimating effect upon Māori, First Nations and Métis knowledges. Moreover, recent reports from commissions and inquiries indicate these knowledges and associated languages continue to decline for a number of reasons, including the impact of contemporary government policies. Health policy, this study asserts, is an uncertain site from which to revitalise Māori, First Nations and Métis knowledges.

year: 2018