title: Probability calibration trees

authors: Leathart, Tim

subjects: computer science

abstract: Obtaining accurate and well calibrated probability estimates from classifiers is useful in many applications, for example, when minimising the expected cost of classifications. Existing methods of calibrating probability estimates are applied globally, ignoring the potential for improvements by applying a more fine-grained model. We propose probability calibration trees, a modification of logistic model trees that identifies regions of the input space in which different probability calibration models are learned to improve performance. We compare probability calibration trees to two widely used calibration methods—isotonic regression and Platt scaling—and show that our method results in lower root mean squared error on average than both methods, for estimates produced by a variety of base learners.

text: Probability calibration trees Obtaining accurate and well calibrated probability estimates from classifiers is useful in many applications, for example, when minimising the expected cost of classifications. Existing methods of calibrating probability estimates are applied globally, ignoring the potential for improvements by applying a more fine-grained model. We propose probability calibration trees, a modification of logistic model trees that identifies regions of the input space in which different probability calibration models are learned to improve performance. We compare probability calibration trees to two widely used calibration methods—isotonic regression and Platt scaling—and show that our method results in lower root mean squared error on average than both methods, for estimates produced by a variety of base learners.

year: 2017

title: Collegiality under pressure: the effects of family demands and flexible work arrangements in the Netherlands

authors: ten Brummelhuis, Lieke L.

subjects: collegiality

abstract: Collegial relationships at work have become more important now that organizations increasingly use team-based work processes. Collegiality is also facing new challenges, however: more employees are meeting heavy demands beyond the workplace and making more frequent use of flexible work arrangements. This study seeks to explain the effect of employees' family demands on collegiality and evaluates whether the use of flexible work arrangements improves or impedes collegial behaviour. Moreover, we aim to investigate collegial behaviour as an exchange process between co-workers, and therefore also take family demands and the use of flexible work arrangements by co-workers into account as predictors of employee collegiality. Based on a sample of 1114 employees from 30 organizations, the results show that when used by the employee and co-workers, flexitime decreases collegiality. Collegiality is decreased when the employee has young children, but increased when co-workers have older children. The implications of these findings for HR practices are discussed.

text: Collegiality under pressure: the effects of family demands and flexible work arrangements in the Netherlands Collegial relationships at work have become more important now that organizations increasingly use team-based work processes. Collegiality is also facing new challenges, however: more employees are meeting heavy demands beyond the workplace and making more frequent use of flexible work arrangements. This study seeks to explain the effect of employees' family demands on collegiality and evaluates whether the use of flexible work arrangements improves or impedes collegial behaviour. Moreover, we aim to investigate collegial behaviour as an exchange process between co-workers, and therefore also take family demands and the use of flexible work arrangements by co-workers into account as predictors of employee collegiality. Based on a sample of 1114 employees from 30 organizations, the results show that when used by the employee and co-workers, flexitime decreases collegiality. Collegiality is decreased when the employee has young children, but increased when co-workers have older children. The implications of these findings for HR practices are discussed.

year: 2010-12

title: Different coloured tears: Dual cultural identity and Tangihanga

authors: Edge, Kiri

subjects: bereavement

abstract: Although whānau/family that are configured by both Pākehā and Māori identities number significantly within New Zealand, there has been little or no attention paid to the ways in which these identities influence the bereavement processes that will inevitably impact upon the lives of these whānau/family. The present study explored the experiences of an individual, whose whānau/family included two life ways: Māori and Pākehā. Of specific focus was the ways in which these identities influenced his bereavement subsequent to the death of his beloved wife, who was of Māori descent. One elderly male Pākehā participant was interviewed, using an open ended narrative approach. The interview was semi-structured around five broad themes, but the focus was upon the participant’s experiences and his preference in expressing these. The data analysis utilised a thematic process which allowed the participant’s experiences to determine the emergent themes. The results depicted the diversity of issues that may be raised for dual cultural whānau/family within bereavement processes. Two central themes are discussed in relation to intercultural conflict and the eventual resolution that was created. Decision-making processes, cultural and language differences played significant roles within the conflict and exclusion experienced by the participant. Communication and compromise provided resolution to the prior conflicts experienced. This created positive and unexpected outcomes which resulted in increased understandings and the strengthening of links between the participant, his whānau/family and his wife’s marae.

text: Different coloured tears: Dual cultural identity and Tangihanga Although whānau/family that are configured by both Pākehā and Māori identities number significantly within New Zealand, there has been little or no attention paid to the ways in which these identities influence the bereavement processes that will inevitably impact upon the lives of these whānau/family. The present study explored the experiences of an individual, whose whānau/family included two life ways: Māori and Pākehā. Of specific focus was the ways in which these identities influenced his bereavement subsequent to the death of his beloved wife, who was of Māori descent. One elderly male Pākehā participant was interviewed, using an open ended narrative approach. The interview was semi-structured around five broad themes, but the focus was upon the participant’s experiences and his preference in expressing these. The data analysis utilised a thematic process which allowed the participant’s experiences to determine the emergent themes. The results depicted the diversity of issues that may be raised for dual cultural whānau/family within bereavement processes. Two central themes are discussed in relation to intercultural conflict and the eventual resolution that was created. Decision-making processes, cultural and language differences played significant roles within the conflict and exclusion experienced by the participant. Communication and compromise provided resolution to the prior conflicts experienced. This created positive and unexpected outcomes which resulted in increased understandings and the strengthening of links between the participant, his whānau/family and his wife’s marae.

year: 2011