title: Human-competitive tagging using automatic keyphrase extraction

authors: Medelyan, Olena

subjects: computer science

abstract: This paper connects two research areas: automatic tagging on the web and statistical keyphrase extraction. First, we analyze the quality of tags in a collaboratively created folksonomy using traditional evaluation techniques. Next, we demonstrate how documents can be tagged automatically with a state-of-the-art keyphrase extraction algorithm, and further improve performance in this new domain using a new algorithm, “Maui”, that utilizes semantic information extracted from Wikipedia. Maui outperforms existing approaches and extracts tags that are competitive with those assigned by the best performing human taggers.

text: Human-competitive tagging using automatic keyphrase extraction This paper connects two research areas: automatic tagging on the web and statistical keyphrase extraction. First, we analyze the quality of tags in a collaboratively created folksonomy using traditional evaluation techniques. Next, we demonstrate how documents can be tagged automatically with a state-of-the-art keyphrase extraction algorithm, and further improve performance in this new domain using a new algorithm, “Maui”, that utilizes semantic information extracted from Wikipedia. Maui outperforms existing approaches and extracts tags that are competitive with those assigned by the best performing human taggers.

year: 2009

title: Visual discrimination and object/picture recognition in hens

authors: Railton, Renee Caron Richards

subjects: hens

abstract: Eight experiments were conducted to examine different aspects of hen’s visual behaviour, and to assess whether hens responded to photographs in the same way they do to the real objects that were depicted in the photographs. In Experiment 1, six hens were trained to perform either a conditional discrimination (successive) or forced-choice discrimination (simultaneous) between flickering (25 Hz) and steady lights. A descending method of limits procedure was then used to increase the flicker speed by 5 Hz over blocks of 20 trials until percentages correct decreased below 55%. The critical flicker fusion frequency of hens was found to range between 68.5 and 95.4 Hz (at a luminance of 300 cd/m2). In Experiment 2, hens were trained to discriminate between steady images presented on a TFT screen, and tested for transfer of that discrimination to a CRT monitor at different refresh rates, on which the images were assumed to appear flickering. It was found that hens showed transfer across all refresh rates with coloured stimuli, but that the degree of transfer decreased as refresh rate decreased with stimuli that were discriminable only on shape. In Experiment 3, a similar decrease in accuracy was shown as refresh rate decreased using a range of stimuli. However, hens did not learn to discriminate all stimuli, and thus transfer could not be assessed with some stimuli. Experiment 4, hens were trained with flickering images and showed relatively high transfer to less flickering, or steady, images. In Experiment 5, a procedure was developed to assess whether hens transferred a discrimination of 3D object to 2D photographs of those objects, and vice versa. In Experiment 6, hens were trained to discriminate stimuli of different colours, or of different shapes. The hens learned to discriminate, and transferred this discrimination, with the coloured shapes. The hens also learned to discriminate the same colour (but differently shaped) stimuli, however, further testing showed that an extraneous variables had come to control behaviour. As a result, the equipment was modified for Experiments 7 and 8. In both experiments, only three of the six hens showed discrimination to any degree, and none transferred this discrimination to photographs or objects. It was concluded that hens do not respond to objects depicted in pictures in the same way they do to the real objects. Thus, these experiments show that that animals’ visual systems need to taken into account when visual stimuli are used in research, and researchers first need to establish that animals can see the visual stimuli and that the method of stimulus presentation is species appropriate if images are to be used as representatives of real world stimuli.

text: Visual discrimination and object/picture recognition in hens Eight experiments were conducted to examine different aspects of hen’s visual behaviour, and to assess whether hens responded to photographs in the same way they do to the real objects that were depicted in the photographs. In Experiment 1, six hens were trained to perform either a conditional discrimination (successive) or forced-choice discrimination (simultaneous) between flickering (25 Hz) and steady lights. A descending method of limits procedure was then used to increase the flicker speed by 5 Hz over blocks of 20 trials until percentages correct decreased below 55%. The critical flicker fusion frequency of hens was found to range between 68.5 and 95.4 Hz (at a luminance of 300 cd/m2). In Experiment 2, hens were trained to discriminate between steady images presented on a TFT screen, and tested for transfer of that discrimination to a CRT monitor at different refresh rates, on which the images were assumed to appear flickering. It was found that hens showed transfer across all refresh rates with coloured stimuli, but that the degree of transfer decreased as refresh rate decreased with stimuli that were discriminable only on shape. In Experiment 3, a similar decrease in accuracy was shown as refresh rate decreased using a range of stimuli. However, hens did not learn to discriminate all stimuli, and thus transfer could not be assessed with some stimuli. Experiment 4, hens were trained with flickering images and showed relatively high transfer to less flickering, or steady, images. In Experiment 5, a procedure was developed to assess whether hens transferred a discrimination of 3D object to 2D photographs of those objects, and vice versa. In Experiment 6, hens were trained to discriminate stimuli of different colours, or of different shapes. The hens learned to discriminate, and transferred this discrimination, with the coloured shapes. The hens also learned to discriminate the same colour (but differently shaped) stimuli, however, further testing showed that an extraneous variables had come to control behaviour. As a result, the equipment was modified for Experiments 7 and 8. In both experiments, only three of the six hens showed discrimination to any degree, and none transferred this discrimination to photographs or objects. It was concluded that hens do not respond to objects depicted in pictures in the same way they do to the real objects. Thus, these experiments show that that animals’ visual systems need to taken into account when visual stimuli are used in research, and researchers first need to establish that animals can see the visual stimuli and that the method of stimulus presentation is species appropriate if images are to be used as representatives of real world stimuli.

year: 2011

title: Housing, mental health, and homelessness: Exploring lived experiences of homelessness to identify barriers to sustainable housing for vulnerable populations

authors: Cresswell, Caitlin Grace

subjects: Homelessness

abstract: Homelessness has become a much talked about topic in Aotearoa New Zealand in 2018 and the preceding years. This thesis explores the experiences of five people who have mental illness and have lived experience of homelessness in Aotearoa New Zealand, and two staff members who work closely with people who experience both mental illness and homelessness. The theoretical frameworks that inform this thesis are narrative research, social constructionism and humanistic psychology. Particular attention was paid to using theoretical frameworks and interview methods that suited Māori (the indigenous population of Aotearoa New Zealand) due to the inequities experienced by Māori in mental health and homelessness, and the majority of participants identifying as New Zealand Māori. Participants’ narratives were gathered using semi- structured interviews. This study argues the importance of a humanistic perspective being used for research on homelessness. In contrast to traditional psychology, humanistic psychology emphasises respecting individual participants’ voice and narratives about their personal experiences of homelessness while considering the environment that influence these narratives. The participants’ narratives reflected their desire to be viewed as more than their life circumstances and illness through the sharing of their life stories. While there has been growing public awareness about mental illness, stigma still exists about mental illness which influences social narratives and how people who have mental illness understand their experiences. I argue that people who are vulnerable to homelessness, like those who experience mental illness, should have better protection from homelessness. To achieve this, I argue that structural barriers to finding, gaining and sustaining housing need to be addressed,
iii
including the design of welfare and housing services. Additionally, there needs to be recognition that the solutions to homelessness are complex and require a whole of system approach to effectively address and prevent homelessness. Recognising the complex nature of homelessness and it’s solutions will help bring a focus to establishing predominantly preventative solutions while also providing emergency housing for people in need.

text: Housing, mental health, and homelessness: Exploring lived experiences of homelessness to identify barriers to sustainable housing for vulnerable populations Homelessness has become a much talked about topic in Aotearoa New Zealand in 2018 and the preceding years. This thesis explores the experiences of five people who have mental illness and have lived experience of homelessness in Aotearoa New Zealand, and two staff members who work closely with people who experience both mental illness and homelessness. The theoretical frameworks that inform this thesis are narrative research, social constructionism and humanistic psychology. Particular attention was paid to using theoretical frameworks and interview methods that suited Māori (the indigenous population of Aotearoa New Zealand) due to the inequities experienced by Māori in mental health and homelessness, and the majority of participants identifying as New Zealand Māori. Participants’ narratives were gathered using semi- structured interviews. This study argues the importance of a humanistic perspective being used for research on homelessness. In contrast to traditional psychology, humanistic psychology emphasises respecting individual participants’ voice and narratives about their personal experiences of homelessness while considering the environment that influence these narratives. The participants’ narratives reflected their desire to be viewed as more than their life circumstances and illness through the sharing of their life stories. While there has been growing public awareness about mental illness, stigma still exists about mental illness which influences social narratives and how people who have mental illness understand their experiences. I argue that people who are vulnerable to homelessness, like those who experience mental illness, should have better protection from homelessness. To achieve this, I argue that structural barriers to finding, gaining and sustaining housing need to be addressed,
iii
including the design of welfare and housing services. Additionally, there needs to be recognition that the solutions to homelessness are complex and require a whole of system approach to effectively address and prevent homelessness. Recognising the complex nature of homelessness and it’s solutions will help bring a focus to establishing predominantly preventative solutions while also providing emergency housing for people in need.

year: 2018