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: Contextual complexities shaping primary teachers' pedagogical practices with digital technologies: An interpretive phenomenological study in the Maldivian ESL context

authors: Mohamed, Zahra

subjects: Pedagogical practices

abstract: Literature on digital technology (DT) integration has revealed a range of complexities around DT use for teaching and learning. Previous research suggests that frequent DT use does not necessarily lead to the pedagogically purposeful use of DTs for student learning. However, the literature overlooks the impact the various contextual and subject content factors may have when exploring teachers’ technological pedagogical practices. This thesis examines teachers’ practices with DTs in relation to the subject content and multilevel context within which teachers’ practices are situated. My study’s context is that of primary education in Maldivian urban and rural schools, with a specific focus on how teachers use DTs in teaching English as a second language (ESL). I also examine the influence of national, school, classroom, and teacher-level factors at play on the participant primary teacher group. The research questions guiding my study are:
1. What impacts do DT use have on ESL pedagogical practices of primary teachers in two Maldivian schools?
2. What contextual factors affect teaching and learning English with and through DTs in two Maldivian schools, and do they differ across schools?
3. What interplay of factors influence Maldivian primary teachers’ DT use in their English lessons?
Adopting an interpretive phenomenological research design meant I could capture the lived experience of nine (four urban and five rural) primary teachers in two Maldivian schools over 8 months. Data collected through lesson observations, postobservation conversations, lesson plans, semistructured interviews, mini surveys and field notes helped in understanding their practices, beliefs, and attitudes about using DTs in ESL lessons. Additionally, other data collected from mini surveys and postobservation conversations with students of the participant teachers, plus interview data and school documents that principals and IT staff provided, helped my understanding of the multilevel contextual factors that influenced teachers’ DT use for teaching and learning.
The findings indicate that an important reason for using DTs was as an attention grabber, perhaps as a set induction, video explanations, form-focused instruction (FFI), and exam-format listening. These findings were examined in relation to the SAMR model to ascertain the pedagogical level of DT use teachers usually applied. The findings also point to the national, school, and classroom factors affecting primary teachers’ practices with DTs in ESL lessons, and these are addressed fully in the Discussion and Conclusion chapters. At the national level, the two factors that have a potential influence on teachers’ DTs use include the development and promulgation of a national educational ICT policy and teacher education, the focus of which needs to move from developing teachers’ technological knowledge to pedagogical applications of tools. While technology leadership and DT-based professional learning and development were factors at the school level, access to DTs and technical support were classroom-level factors that significantly influenced participant teachers’ decisions around DT use. Apart from these external factors, internal or teacher-level factors such as teachers’ knowledge, beliefs, attitudes, and existing pedagogical practices shaped their practices with DTs when teaching English.
This study has contributed to the literature by identifying primary teachers’ ESL pedagogical practices with DTs. For one thing, it fills a significant gap in TPACK research which often considers TPACK to be subject-independent. My research, therefore, contributes by showing the connection between technology, pedagogy, and subject-specific content (English language). Another contribution is the use of classroom observation data to capture teachers’ DT use, as DT integration literature predominantly uses self-reported data. My research also contributes to a TPACK-in-Context framework (Figure 2.4) adapted from the TPACK framework (Mishra & Koehler, 2006) to provide a contextually situated understanding of primary teachers’ DT use in ESL lessons. Additionally, the NVivo-enhanced Spiral QDA process (Figure 3.7) I adapted from Seidel’s (1998) qualitative data analysis (QDA) model contributes to understanding the nonlinear, recursive, and iterative nature of the qualitative data analysis process. Finally, my illustration of the complex interplay of factors affecting the pedagogical use of DTs (Figure 5.2) contributes to the understanding of the relationships between TPACK (Mishra & Koehler, 2006), TAM (Davis, 1989), and SAMR (Puentedura, 2012), three dominant models/frameworks in DT literature.

text: Contextual complexities shaping primary teachers' pedagogical practices with digital technologies: An interpretive phenomenological study in the Maldivian ESL context Literature on digital technology (DT) integration has revealed a range of complexities around DT use for teaching and learning. Previous research suggests that frequent DT use does not necessarily lead to the pedagogically purposeful use of DTs for student learning. However, the literature overlooks the impact the various contextual and subject content factors may have when exploring teachers’ technological pedagogical practices. This thesis examines teachers’ practices with DTs in relation to the subject content and multilevel context within which teachers’ practices are situated. My study’s context is that of primary education in Maldivian urban and rural schools, with a specific focus on how teachers use DTs in teaching English as a second language (ESL). I also examine the influence of national, school, classroom, and teacher-level factors at play on the participant primary teacher group. The research questions guiding my study are:
1. What impacts do DT use have on ESL pedagogical practices of primary teachers in two Maldivian schools?
2. What contextual factors affect teaching and learning English with and through DTs in two Maldivian schools, and do they differ across schools?
3. What interplay of factors influence Maldivian primary teachers’ DT use in their English lessons?
Adopting an interpretive phenomenological research design meant I could capture the lived experience of nine (four urban and five rural) primary teachers in two Maldivian schools over 8 months. Data collected through lesson observations, postobservation conversations, lesson plans, semistructured interviews, mini surveys and field notes helped in understanding their practices, beliefs, and attitudes about using DTs in ESL lessons. Additionally, other data collected from mini surveys and postobservation conversations with students of the participant teachers, plus interview data and school documents that principals and IT staff provided, helped my understanding of the multilevel contextual factors that influenced teachers’ DT use for teaching and learning.
The findings indicate that an important reason for using DTs was as an attention grabber, perhaps as a set induction, video explanations, form-focused instruction (FFI), and exam-format listening. These findings were examined in relation to the SAMR model to ascertain the pedagogical level of DT use teachers usually applied. The findings also point to the national, school, and classroom factors affecting primary teachers’ practices with DTs in ESL lessons, and these are addressed fully in the Discussion and Conclusion chapters. At the national level, the two factors that have a potential influence on teachers’ DTs use include the development and promulgation of a national educational ICT policy and teacher education, the focus of which needs to move from developing teachers’ technological knowledge to pedagogical applications of tools. While technology leadership and DT-based professional learning and development were factors at the school level, access to DTs and technical support were classroom-level factors that significantly influenced participant teachers’ decisions around DT use. Apart from these external factors, internal or teacher-level factors such as teachers’ knowledge, beliefs, attitudes, and existing pedagogical practices shaped their practices with DTs when teaching English.
This study has contributed to the literature by identifying primary teachers’ ESL pedagogical practices with DTs. For one thing, it fills a significant gap in TPACK research which often considers TPACK to be subject-independent. My research, therefore, contributes by showing the connection between technology, pedagogy, and subject-specific content (English language). Another contribution is the use of classroom observation data to capture teachers’ DT use, as DT integration literature predominantly uses self-reported data. My research also contributes to a TPACK-in-Context framework (Figure 2.4) adapted from the TPACK framework (Mishra & Koehler, 2006) to provide a contextually situated understanding of primary teachers’ DT use in ESL lessons. Additionally, the NVivo-enhanced Spiral QDA process (Figure 3.7) I adapted from Seidel’s (1998) qualitative data analysis (QDA) model contributes to understanding the nonlinear, recursive, and iterative nature of the qualitative data analysis process. Finally, my illustration of the complex interplay of factors affecting the pedagogical use of DTs (Figure 5.2) contributes to the understanding of the relationships between TPACK (Mishra & Koehler, 2006), TAM (Davis, 1989), and SAMR (Puentedura, 2012), three dominant models/frameworks in DT literature.

year: 2023

title: Association of Single Nucleotide Polymorphisms in Surfactant Protein A and D with Otitis Media.

authors: Barnett, Catherine Margaret Eleanor

subjects: otitis media

abstract: Otitis Media is one of the most common childhood diseases. Recurrent acute otitis media RAOM is characterized by repeated episodes of inflammation of the middle ear in conjunction with middle ear fluid, and often with an inflamed or bulging eardrum. Defective clearance by the Eustachian tube results in mucus build-up and is characteristic of otitis media with effusion (OME). Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, respiratory syncytial virus, and rhinovirus are the most common contributors to otitis media pathogenesis. In New Zealand, OME has been implicated with conductive hearing loss in childhood and has been shown to significantly impact on speech and language development. New Zealand Māori and Polynesian children have displayed significantly higher hearing test failure rates than European-Caucasian children.

The collectins, Surfactant Protein (SP)-A and -D are encoded by three genes (SP-A1, SP-A2, and SP-D) and are host defense proteins present in the middle ear and Eustachian tube. Single nucleotide polymorphisms (SNPs) in SP-A1 and SP-A2 have been associated with increased or decreased susceptibility to otitis media, meningococcal disease, and range of respiratory diseases. Using allele-specific primers and real-time PCR with SYBR  Green I melting curve analysis, four groups of individuals were genotyped for eleven SP-A1, SP-A2, and SP-D SNPs: European-Caucasian individuals with RAOM/OME; New Zealand Māori/Polynesian individuals with RAOM/OME; individuals with meningococcal disease; and a control group. The computer program, Haploview, was employed to perform χ2 analyses and identify statistically significant associations of alleles/haplotypes with RAOM/OME or meningococcal disease.

In the European-Caucasian population, two SP-A1 alleles, one SP-A2 allele, and four haplotypes (CGAGC, 1A3, 1A9, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). Conversely, haplotypes 6A2 and 1A2 were found to be protective against susceptibility to RAOM/OME (P lt; 0.05). In New Zealand Māori and Polynesian individuals, two SP-A1 alleles, three SP-A2 alleles, one SP-D allele, and four haplotypes (6A8, 6A10, 1A3, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). An additional four haplotypes (6A2, 1A0, 1A2, and TA) were determined to be protective against susceptibility to RAOM/OME (P lt; 0.05). However, protective SPA1/SPA2/SPD haplotype 6A2-1A0-TA was significantly under-represented in the New Zealand Māori and Polynesian population (P lt; 0.05). A single allele and haplotype were associated with increased risk of meningococcal disease (P lt; 0.05).

The findings of this study confirm that specific genetic variants of SP-A and SP-D are associated with either increased or decreased risk of developing RAOM and/or OME. Furthermore, it was demonstrated that New Zealand Māori and Polynesian individuals appear to exhibit more haplotypes susceptible to RAOM/OME. This may provide a partial explanation for the higher RAOM/OME-related failure rates of hearing tests in New Zealand Māori and Polynesian children. However, there are numerous socio-economic and environmental factors that also contribute to otitis media pathogenesis which were not considered in this study. The effects of the SP-A1, SP-A2, and SP-D alleles and haplotypes on the bacterial/viral binding efficiencies of SP-A and SP-D need to be investigated by further research, using a large population, to confirm the association with susceptibility or resistance with RAOM/OME.

text: Association of Single Nucleotide Polymorphisms in Surfactant Protein A and D with Otitis Media. Otitis Media is one of the most common childhood diseases. Recurrent acute otitis media RAOM is characterized by repeated episodes of inflammation of the middle ear in conjunction with middle ear fluid, and often with an inflamed or bulging eardrum. Defective clearance by the Eustachian tube results in mucus build-up and is characteristic of otitis media with effusion (OME). Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, respiratory syncytial virus, and rhinovirus are the most common contributors to otitis media pathogenesis. In New Zealand, OME has been implicated with conductive hearing loss in childhood and has been shown to significantly impact on speech and language development. New Zealand Māori and Polynesian children have displayed significantly higher hearing test failure rates than European-Caucasian children.

The collectins, Surfactant Protein (SP)-A and -D are encoded by three genes (SP-A1, SP-A2, and SP-D) and are host defense proteins present in the middle ear and Eustachian tube. Single nucleotide polymorphisms (SNPs) in SP-A1 and SP-A2 have been associated with increased or decreased susceptibility to otitis media, meningococcal disease, and range of respiratory diseases. Using allele-specific primers and real-time PCR with SYBR  Green I melting curve analysis, four groups of individuals were genotyped for eleven SP-A1, SP-A2, and SP-D SNPs: European-Caucasian individuals with RAOM/OME; New Zealand Māori/Polynesian individuals with RAOM/OME; individuals with meningococcal disease; and a control group. The computer program, Haploview, was employed to perform χ2 analyses and identify statistically significant associations of alleles/haplotypes with RAOM/OME or meningococcal disease.

In the European-Caucasian population, two SP-A1 alleles, one SP-A2 allele, and four haplotypes (CGAGC, 1A3, 1A9, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). Conversely, haplotypes 6A2 and 1A2 were found to be protective against susceptibility to RAOM/OME (P lt; 0.05). In New Zealand Māori and Polynesian individuals, two SP-A1 alleles, three SP-A2 alleles, one SP-D allele, and four haplotypes (6A8, 6A10, 1A3, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). An additional four haplotypes (6A2, 1A0, 1A2, and TA) were determined to be protective against susceptibility to RAOM/OME (P lt; 0.05). However, protective SPA1/SPA2/SPD haplotype 6A2-1A0-TA was significantly under-represented in the New Zealand Māori and Polynesian population (P lt; 0.05). A single allele and haplotype were associated with increased risk of meningococcal disease (P lt; 0.05).

The findings of this study confirm that specific genetic variants of SP-A and SP-D are associated with either increased or decreased risk of developing RAOM and/or OME. Furthermore, it was demonstrated that New Zealand Māori and Polynesian individuals appear to exhibit more haplotypes susceptible to RAOM/OME. This may provide a partial explanation for the higher RAOM/OME-related failure rates of hearing tests in New Zealand Māori and Polynesian children. However, there are numerous socio-economic and environmental factors that also contribute to otitis media pathogenesis which were not considered in this study. The effects of the SP-A1, SP-A2, and SP-D alleles and haplotypes on the bacterial/viral binding efficiencies of SP-A and SP-D need to be investigated by further research, using a large population, to confirm the association with susceptibility or resistance with RAOM/OME.

year: 2007