title: Eliciting Expert Uncertainty from Decision Making

authors: Falconer, Julia Ruth

subjects: bayesian

abstract: Eliciting expert uncertainty is a complex task with many caveats. Its usefulness in high-level decision-making and Bayesian inference makes it a necessary task that must be completed accurately. This thesis explores uncertainty elicitation in terms of prior elicitation for Bayesian inference and the wider knowledge elicitation  field. It describes methods currently available for prior elicitation and proposes a new typology, highlighting lesser-known methods. Based on the limitations of current methods, a new method for prior elicitation is introduced. This new method allows an analyst to model expert decision-making data to elicit a probability distribution that reflects expert uncertainty. An example of parole board decision-making is used to elicit a prior distribution of a prisoner re-offending upon release from prison. This example shows analysts how to elicit distributions for tabular data; however, more complex data types, such as images and reports, are often used for decision-making. To elicit distributions capturing expert uncertainty from more complex data, this thesis introduces a deep learning approach and uses an example of eliciting cancer risk, in histopathology, to illustrate this approach for the wider knowledge elicitation field.

text: Eliciting Expert Uncertainty from Decision Making Eliciting expert uncertainty is a complex task with many caveats. Its usefulness in high-level decision-making and Bayesian inference makes it a necessary task that must be completed accurately. This thesis explores uncertainty elicitation in terms of prior elicitation for Bayesian inference and the wider knowledge elicitation  field. It describes methods currently available for prior elicitation and proposes a new typology, highlighting lesser-known methods. Based on the limitations of current methods, a new method for prior elicitation is introduced. This new method allows an analyst to model expert decision-making data to elicit a probability distribution that reflects expert uncertainty. An example of parole board decision-making is used to elicit a prior distribution of a prisoner re-offending upon release from prison. This example shows analysts how to elicit distributions for tabular data; however, more complex data types, such as images and reports, are often used for decision-making. To elicit distributions capturing expert uncertainty from more complex data, this thesis introduces a deep learning approach and uses an example of eliciting cancer risk, in histopathology, to illustrate this approach for the wider knowledge elicitation field.

year: 2024

title: A distributed adaptive debugger server

authors: Wong, Derek Antony

abstract: A model and corresponding protocol suitable for debugging distributed embedded systems is developed. Protocol design issues and a formal model of the debugger server are defined with the intent of developing an extensible debug server to aid the development of dynamically retargettable debug clients suitable for application to heterogeneous distributed systems. 

The thesis considers one of the major problems faced in embedded systems, that of dynamic configuration of system components. The namespace model described solves these issues in a way that provides for the development of dynamic “hot insertion, plug and play” systems. This model is applied throughout the design of the protocol toward the development of debug services. 

The model is formally developed using the specification language, VDM-SL. Specifications of the model are given implicitly and then derived to an explicit executable form except for target-dependencies. Informal correctness proofs are carried out where necessary to show that the transformation from implicit to explicit form is valid and that the model and protocols themselves are valid. The specifications have been syntax and type checked using the IFAD VDM Toolbox; a CASE tool based on the 1996 ISO VDM-SL standard that provides an environment for the development and testing of VDM-SL specifications.

text: A distributed adaptive debugger server A model and corresponding protocol suitable for debugging distributed embedded systems is developed. Protocol design issues and a formal model of the debugger server are defined with the intent of developing an extensible debug server to aid the development of dynamically retargettable debug clients suitable for application to heterogeneous distributed systems. 

The thesis considers one of the major problems faced in embedded systems, that of dynamic configuration of system components. The namespace model described solves these issues in a way that provides for the development of dynamic “hot insertion, plug and play” systems. This model is applied throughout the design of the protocol toward the development of debug services. 

The model is formally developed using the specification language, VDM-SL. Specifications of the model are given implicitly and then derived to an explicit executable form except for target-dependencies. Informal correctness proofs are carried out where necessary to show that the transformation from implicit to explicit form is valid and that the model and protocols themselves are valid. The specifications have been syntax and type checked using the IFAD VDM Toolbox; a CASE tool based on the 1996 ISO VDM-SL standard that provides an environment for the development and testing of VDM-SL specifications.

year: 2001

title: Visitors' satisfaction with heritage sites in New Zealand: Causes and complexities, clusters and causes

authors: Trinh, Thi Thu

subjects: Heritage Tourism

abstract: The thesis presents findings from a survey of over 1,000 visitors at three New Zealand heritage sites. These sites were Te Puia, the Rotorua Bathhouse Museum and the Rangiriri Battlefield Interpretation Centre. All three represent a key period in New Zealand’s history from the period of approximately 1840 to 1900, but in the case of Te Puia there is also a continuing contemporary cultural importance. This last site, located in Rotorua, was founded as the Maori Arts and Crafts Institute and was established to perpetuate Maori tradition skills in areas such as carving and weaving. Its location was in part determined by the volcanic nature of the valley, long inhabited by members of Te Arawa tribal people. The site has a strong connection with tourism as Te Arawa have entertained tourists from the mid-nineteenth century in the volcanic area. The site therefore represents a tourism site from the perspective of history, culture and natural heritage. The Bathhouse Museum represents a period of late colonial architecture while the third site, the Rangiriri Battlefield is based on the remnants of the Pa (Maori fortifications) that was the site of a battle between the colonial government forces and the Maori Kingi movement on November 23rd 1840.

The motive for the research was to provide a profile of visitors for the respective sites and their management, and then to assess to what degree socio-demographics might be explanatory variables in determining future visitation. The core theories being employed revolved around concepts of levels of interest in heritage and historic sites, the intellectual search for knowledge, and the degree to which people became involved in the activity of heritage site visitation. The work was driven by the finding that only about 11 per cent of visits to cultural tourism sites were ‘purposeful’ tourists as defined by McKercher and Du Cros (2002). Being purposeful implies having specific degrees of interest, of becoming involved and possibly seeking meanings that implied senses of identity. That is, self-awareness accrued from having a better understanding of the past as a means of knowing about the present. This conceptualisation implies use of the theories of involvement, benefits and self-awareness, and the managerial aspects of interpretation.  Normally such an approach has been seen by many researchers as a determinant of satisfaction, but in this thesis satisfaction is not seen as simply an end to a process. Rather, this thesis argues that to be satisfied entails not only cognitive and affective components, but also the conative. That conative component can include making recommendations to others, making visits to other heritage sites, or joining organisations associated with heritage sites such as the New Zealand Historic Place Trust. These form key themes in the literature review.

Unfortunately, while these premises emerged from the literature review and informed the hypotheses that are later described in the thesis, they were not wholly supported by the data. It is suggested that one reason for this, from a statistical perspective, was that measures used were subject to multi-collinearity and auto-correlation – put simply, many of the variables are not independent from each other. For example, it is suggested that satisfaction is actually enhanced by subsequently being able to make recommendations to friends and others; that the act of making a recommendation enhances one’s own self in both the eyes of that friend or through an enhanced self- perception of being helpful, and thus auto-correlation may exist between these variables.

This realisation thus leads, in the conclusions of Chapter Eight, to new suggestions for potential future researchers concerning ways of looking at the nature of involvement that draw on distinctions between situational and enduring involvement. Finally, it also needs to be noted that tourists are not lay historians, but are the makers of their holidays, and hence the debate is contextualised within the act of being on holiday, which itself is a period of escape and relaxation for many. Hence the relationships being examined in this thesis are complex, interactive and yet rewarding to untangle.

text: Visitors' satisfaction with heritage sites in New Zealand: Causes and complexities, clusters and causes The thesis presents findings from a survey of over 1,000 visitors at three New Zealand heritage sites. These sites were Te Puia, the Rotorua Bathhouse Museum and the Rangiriri Battlefield Interpretation Centre. All three represent a key period in New Zealand’s history from the period of approximately 1840 to 1900, but in the case of Te Puia there is also a continuing contemporary cultural importance. This last site, located in Rotorua, was founded as the Maori Arts and Crafts Institute and was established to perpetuate Maori tradition skills in areas such as carving and weaving. Its location was in part determined by the volcanic nature of the valley, long inhabited by members of Te Arawa tribal people. The site has a strong connection with tourism as Te Arawa have entertained tourists from the mid-nineteenth century in the volcanic area. The site therefore represents a tourism site from the perspective of history, culture and natural heritage. The Bathhouse Museum represents a period of late colonial architecture while the third site, the Rangiriri Battlefield is based on the remnants of the Pa (Maori fortifications) that was the site of a battle between the colonial government forces and the Maori Kingi movement on November 23rd 1840.

The motive for the research was to provide a profile of visitors for the respective sites and their management, and then to assess to what degree socio-demographics might be explanatory variables in determining future visitation. The core theories being employed revolved around concepts of levels of interest in heritage and historic sites, the intellectual search for knowledge, and the degree to which people became involved in the activity of heritage site visitation. The work was driven by the finding that only about 11 per cent of visits to cultural tourism sites were ‘purposeful’ tourists as defined by McKercher and Du Cros (2002). Being purposeful implies having specific degrees of interest, of becoming involved and possibly seeking meanings that implied senses of identity. That is, self-awareness accrued from having a better understanding of the past as a means of knowing about the present. This conceptualisation implies use of the theories of involvement, benefits and self-awareness, and the managerial aspects of interpretation.  Normally such an approach has been seen by many researchers as a determinant of satisfaction, but in this thesis satisfaction is not seen as simply an end to a process. Rather, this thesis argues that to be satisfied entails not only cognitive and affective components, but also the conative. That conative component can include making recommendations to others, making visits to other heritage sites, or joining organisations associated with heritage sites such as the New Zealand Historic Place Trust. These form key themes in the literature review.

Unfortunately, while these premises emerged from the literature review and informed the hypotheses that are later described in the thesis, they were not wholly supported by the data. It is suggested that one reason for this, from a statistical perspective, was that measures used were subject to multi-collinearity and auto-correlation – put simply, many of the variables are not independent from each other. For example, it is suggested that satisfaction is actually enhanced by subsequently being able to make recommendations to friends and others; that the act of making a recommendation enhances one’s own self in both the eyes of that friend or through an enhanced self- perception of being helpful, and thus auto-correlation may exist between these variables.

This realisation thus leads, in the conclusions of Chapter Eight, to new suggestions for potential future researchers concerning ways of looking at the nature of involvement that draw on distinctions between situational and enduring involvement. Finally, it also needs to be noted that tourists are not lay historians, but are the makers of their holidays, and hence the debate is contextualised within the act of being on holiday, which itself is a period of escape and relaxation for many. Hence the relationships being examined in this thesis are complex, interactive and yet rewarding to untangle.

year: 2013