title: Efficient algorithms for conditional independence inference

authors: Bouckaert, Remco R.

subjects: computer science

abstract: The topic of the paper is computer testing of (probabilistic) conditional independence (CI) implications by an algebraic method of structural imsets. The basic idea is to transform (sets of) CI statements into certain integral vectors and to verify by a computer the corresponding algebraic relation between the vectors, called the independence implication. We interpret the previous methods for computer testing of this implication from the point of view of polyhedral geometry. However, the main contribution of the paper is a new method, based on linear programming (LP). The new method overcomes the limitation of former methods to the number of involved variables. We recall/describe the theoretical basis for all four methods involved in our computational experiments, whose aim was to compare the efficiency of the algorithms. The experiments show that the LP method is clearly the fastest one. As an example of possible application of such algorithms we show that testing inclusion of Bayesian network structures or whether a CI statement is encoded in an acyclic directed graph can be done by the algebraic method.

text: Efficient algorithms for conditional independence inference The topic of the paper is computer testing of (probabilistic) conditional independence (CI) implications by an algebraic method of structural imsets. The basic idea is to transform (sets of) CI statements into certain integral vectors and to verify by a computer the corresponding algebraic relation between the vectors, called the independence implication. We interpret the previous methods for computer testing of this implication from the point of view of polyhedral geometry. However, the main contribution of the paper is a new method, based on linear programming (LP). The new method overcomes the limitation of former methods to the number of involved variables. We recall/describe the theoretical basis for all four methods involved in our computational experiments, whose aim was to compare the efficiency of the algorithms. The experiments show that the LP method is clearly the fastest one. As an example of possible application of such algorithms we show that testing inclusion of Bayesian network structures or whether a CI statement is encoded in an acyclic directed graph can be done by the algebraic method.

year: 2010

title: Re-evaluating risk and exploring educational alternatives

authors: Brown, Mike

subjects: outdoor adventure education

abstract: Risk is positioned as a distinguishing feature of outdoor adventure education (OAE) pedagogy. Risk defines much of what happens in OAE, from participants 'taking' risks to instructors 'managing' risks. The taken-for-granted centrality of risk continues to have currency due to the thrill and allure of adventurous outdoor activities. This paper questions the centrality of some current conceptions of risk in OAE and explores an alternative pedagogical perspective where risk is less central. A sociocultural lens expands possibilities for how OAE is conceptualized, with a focus more on learning than on risk. This alternative approach is well supported by research on teaching and learning, and as such offers an opportunity to broaden instructors' repertoires of practice for the benefit of OAE participants.

text: Re-evaluating risk and exploring educational alternatives Risk is positioned as a distinguishing feature of outdoor adventure education (OAE) pedagogy. Risk defines much of what happens in OAE, from participants 'taking' risks to instructors 'managing' risks. The taken-for-granted centrality of risk continues to have currency due to the thrill and allure of adventurous outdoor activities. This paper questions the centrality of some current conceptions of risk in OAE and explores an alternative pedagogical perspective where risk is less central. A sociocultural lens expands possibilities for how OAE is conceptualized, with a focus more on learning than on risk. This alternative approach is well supported by research on teaching and learning, and as such offers an opportunity to broaden instructors' repertoires of practice for the benefit of OAE participants.

year: 2009

title: Are we really colour-blind? The normalisation of mass female incarceration

authors: Norris, Adele N.

abstract: The sharp rise in female incarceration rates in both the United States and New Zealand has received increased attention. Even more pressing are the racial disparities among imprisoned females. This exploratory case study examines 13 peer-reviewed articles published between 2005 and 2016 to understand the nature of colour-blind ideology in discussions of female imprisonment in New Zealand. Several themes emerged including the homogenisation of female prisoners. Apart from moderately linking vast racial disparities between incarcerated White women and Indigenous women to ill-defined colonial practices, contemporary explanations for the substantial racial disparities receive little attention. This article concludes that the absence of a critical lens toward contemporary forms and experiences of racism undergirding the mass criminalisation of Indigenous people perpetuates a colour blindness that in turn works to normalise mass female incarceration. Even in attempts to be unbiased, the way race/ethnicity, gender, age, and class are discussed in academic research exploring female incarceration seems to reflect the influential nature of controlling images rather than critique them.

text: Are we really colour-blind? The normalisation of mass female incarceration The sharp rise in female incarceration rates in both the United States and New Zealand has received increased attention. Even more pressing are the racial disparities among imprisoned females. This exploratory case study examines 13 peer-reviewed articles published between 2005 and 2016 to understand the nature of colour-blind ideology in discussions of female imprisonment in New Zealand. Several themes emerged including the homogenisation of female prisoners. Apart from moderately linking vast racial disparities between incarcerated White women and Indigenous women to ill-defined colonial practices, contemporary explanations for the substantial racial disparities receive little attention. This article concludes that the absence of a critical lens toward contemporary forms and experiences of racism undergirding the mass criminalisation of Indigenous people perpetuates a colour blindness that in turn works to normalise mass female incarceration. Even in attempts to be unbiased, the way race/ethnicity, gender, age, and class are discussed in academic research exploring female incarceration seems to reflect the influential nature of controlling images rather than critique them.

year: 2017