Browsing by Subject "Categorization"
Now showing 1 - 9 of 9
Results Per Page
Sort Options
Item Automated Pattern Recognition for Intonation (PRInt) : an essay on intonational phonology and categorization(2012-12) Bacuez, Nicholas; Montreuil, Jean-Pierre; Blyth, Carl; Bullock, Barbara; Erk, Katrin; Smiljanic, RajkaThis dissertation provides experimental evidence for the validity of an intonational phonology. The widely used Autosegmental-Metrical theory con- tends that the phonological structure of intonation can be expressed with two tonal targets (L/H tones and derivatives) and retrieved from its phonetic im- plementations. However, it has not been specifically demonstrated so far in a systematic way. This dissertation argues that this view on intonational phonol- ogy considers the phonetic forms of intonation as instances of phonologically structured intonational units forming functionally discrete categories (tones and derivatives). The model of Pattern Recognition for Intonation (PRInt) applies the concepts of categorization (vagueness, prototype, degrees of typicality) to in- tonation in order to abstract the phonological structure of intonational cate- gories from the ranking, by degree of typicality, of their variations in phonetic implementation. First, instances belonging to an intonation category are collected. Sec- ond, a pattern recognition module, relying on the 4-layer structure protocol, extracts a feature vector from the phonetic data of each instance: a sequence of structurally organized tones (L/H tones and derivatives). Third, a fuzzy classifier, using two functions (frequency and similar- ity), organizes the data from the feature vectors of all instances by degree of typicality (grade of membership of values in multisets) and generates the phonological structure of the intonation category, the prototypical pattern, ex- tracted from all instances, and that subsumes them all. It also re-creates the phonetic implementations of the phonological structure but with their features ranked by degree of typicality. This allows the model to distinguish phono- logically distinct structures from phonetic variations of the same phonological structure. The model successfully extracted the phonological intonation structure associated to three modalities of closed questions in French: neutral, doubt- ful, and surprised. It found that neutral and doubtful closed questions are phonologically distinct while surprise is a phonetic allocontour of the neutral modality, in line with prior characterizations of these patterns. It demon- strated that a bi-tonal phonological structure of intonation can be retrieved from phonetic variations. A versatile modeling tool, PRInt will be developed to use its acquired knowledge to evaluate the categorical status of novel instances and to extract multiple phonological units from mixed corpora.Item The aviation safety action program : assessment of the threat and error management model for improving the quantity and quality of reported information(2011-05) Harper, Michelle Loren; Helmreich, Robert L.; Gosling, Sam; Markman, Art; Lewis, Marc; Halford, Carl; Tesmer, BruceThe Aviation Safety Action Program (ASAP) is a voluntary, non-jeopardy reporting program supported by commercial airlines. The program provides pilots with a way to report unsafe occurrences, including their own errors, without risk of punitive action on the part of the airlines or the Federal Aviation Administration (FAA). Through a set of on-site visits to airlines with ASAP programs, deficiencies were identified in the way airlines collect ASAP reports from pilots. It was concluded that these deficiencies might be limiting the ability of airlines to identify hazards contributing to reported safety events. The purpose of this research was to determine if the use of an ASAP reporting form based on a human factors model, referred to as the Threat and Error Management (TEM) model, would result in pilots providing a larger quantity and higher quality of information as compared to information provided by pilots using a standard ASAP reporting form. The TEM model provides a framework for a taxonomy that includes factors related to safety events pilots encounter, behaviors and errors they make, and threats associated with the complexities of their operational environment. A comparison of reports collected using the TEM Reporting Form and a standard reporting form demonstrated that narrative descriptions provided by pilots using the TEM Reporting Form included both a larger quantity and higher quality of information. Quantity of information was measured by comparing the average word count of the narrative descriptions. Quality of information was measured by comparing the discriminatory power of the words in the narrative descriptions and the extent to which the narrative descriptions from the two sets of reports contributed to a set of latent concepts. The findings suggest that the TEM Reporting Form can help pilots provide longer descriptions, more relevant information related to safety hazards, and expand on concepts that contribute to reported safety events. The use of the TEM Reporting Form for the collection of ASAP reports should be considered by airlines as a preferred collection method for improving the quantity and quality of information reported by pilots through ASAP programs.Item Break down the walls : how the “folder effect” influences the transfer of learning(2011-05) He, Jingjie; Svinicki, Marilla D., 1946-; Markman, ArthurCategorizing knowledge into different disciplines and units may block knowledge within separate “folders”, which could limit its later retrieval and transfer to new contexts. To test this hypothesis, two experiments had been conducted. In one experiment, participants memorized a list of words with or without cuing which category these words belonged to. One week later, they were asked to recall all the positive adjectives, which required them to retrieve words that came from different categories. In the other experiment, participants read exactly the same story but embedded in two different subject domains or no context. A survey report was presented to test whether people from different contexts would have different transfer effect. The current study replicated previous results that successful transfer was hard to observe in the laboratory settings without explicit prompts. The memory test and transfer task in this study were too difficult and resulted into to the poor performance of the participants. The initial hypothesis had been neither supported nor rejected. To test the hypothesis, future studies could reduce the time interval between study and test, and modified the transfer task to lower the difficulty of the experiment.Item Declarative category learning system(2010-05) Davis, Tyler Harrison; Love, Bradley C.; Maddox, W T.; Neubauer, Raymond; Preston, Alison R.; Schnyer, David M.Categorization is a fundamental process that underlies much of cognition. People form categories that allow them to generalize to and make inferences about novel objects and events. Current accounts of category learning suggest that there are two systems for learning categories, an explicit rule-based system that depends on frontal-striatal loops and working memory, and a procedural system that learns implicitly and depends on the tail of the caudate nucleus and occipital regions. In the present thesis, I propose that an additional declarative category learning system exists that is recruited to learn categories that are associated with multiple conjunctive and explicit, but not strictly rule-based, representations. The basis of the declarative category learning system is then tested in several behavioral and physiological recording experiments. The first issue that is examined in relation to the declarative category learning system is how subjects’ ability to encode stimuli affects their ability to form new flexible conjunctive representations. I provide evidence consistent with the idea that there are two ways to encode stimuli in category learning, either as a conjunction of individual parts or as holistic images. Forming part-based representations is found to be especially critical for forming new conjunctive representations for exceptions in brief single session experiments. A second question is how emotional processes interact with the declarative category learning system. Numerous lines of evidence suggest that emotional processes strongly affect learning and behavior. In a study using skin conductance, I find that anticipatory emotions (i.e., emotions present before a behavioral response) show a pattern consistent with orienting attention to behaviorally significant or potentially novel events. A final fMRI project ties together hypotheses about anticipatory emotions and encoding to their neural basis and provides a test of the predicted mapping of the declarative category learning system to the brain. By relating quantitative predictions from SUSTAIN, a model that shares relationships to the medial temporal lobes (MTL) and declarative category learning system, to fMRI data, I find clusters in an MTL-midbrain-PFC network that show patterns of activation consistent with recognizing exception items and updating these representations in response to error or surprise.Item Graded structure of defect categories in automated defect classification(Texas Tech University, 1996-05) Wong, Wan SangDefect review and classification are time consuming, monotonous, fatiguing, and very subjective tasks. Large amount of variability has been observed from different operators, same operator for the same wafer, from wafer to wafer, or from day to day depending on the type of defects observed. This research hypothesizes the problem as due mainly to the graded structure of semiconductor defect categories. Every category exhibits a graded structure. Graded structure refers to degree of membership representation from the most typical to atypical members of a category to those nonmembers that are least similar to the category members. Two levels of categorization and therefore two levels of graded structures occur in knowledge-based defect classification which can adversely affect the performance of the system. The first level of graded structure occurs in the design of defect knowledge base when the defect expert describes defect categories in terms of defects' visual features using linguistic variables. Feature values which are acquired subjectively and represented in natural language are most subjected to the limitation associated with graded structure. Graded structure level two occurs in the actual defect classification where feature similarities between the actual defect and the categorical defects are compared. The focus of this research is minimization of the effect of graded structure in automated defect classification for patterned semiconductor wafers. This research provides insights into the use of standardization and feature combination as a way to minimize the effect of graded structure on categorization. Level one graded structure can be minimized by standardizing defect features, e.g. by representing them as fuzzy sets. The level two graded structure can be minimized by combining human-based and computationally-derived defect features in categorization. Human generated object features are directly visible and recognizable to a human observer while computationally-derived features are not directly perceptible by humans.Item Men, masculinity, and heterosexual exclusivity : a study of the perception and construction of human sexual orientation(2013-08) Gordon, Aqualus Mondrell; Ainslie, Ricardo C.In this dissertation I investigate how individuals group others into sexual orientation (SO) categories based on a target's known sexual behaviors and romantic interests. I hypothesize that individuals known to have any non-heterosexual sexual or romantic interests are more likely to be perceived as "gay" (and not "straight") even when there is clear evidence of heterosexual interests and behaviors as well. This phenomenon has been termed "heterosexual exclusivity" in this work. In the process, I examine relevant writings and research on SO, including works related to SO in history, the conceptualization and measurement of SO, determinants of and influences on SO, the essentialism and social constructionism debate with regard to SO, innate bisexuality, and bisexual erasure. Additionally, I give specific focus to how and why men are affected by, as well as perpetuate heterosexual exclusivity. In doing so, I examine writings and research on the role and construction of masculinity as well as homophobia and the overlap of the two. I hypothesize that adherence to traditional masculinity and increased homophobia are predictive of increased heterosexual exclusivity in men. I also hypothesize that men are more likely to be the primary agents and targets of heterosexual [exclusivity]. The results supported most of these hypotheses.Item Reevaluating the determinants of category-based induction(2010-05) Rein, Jonathan Raymond, 1983-; Markman, Arthur B.; Griffin, Zenzi; Legare, Cristine; Loewenstein, Jeffrey; Maddox, ToddWhat makes one more or less likely to project a novel property from an item to that item’s broader category? Research on category-based induction has documented a consistent typicality effect: typical exemplars promote stronger inferences than atypical exemplars. This work has been largely confined to categories whose central tendencies are the most typical members of the category. Experiments 1 and 2, using natural and artificial categories, showed that central tendencies have greatest induction strength even for categories that are best represented by ideal exemplars. Experiments 3-7 investigate the role of familiarity in induction. Experiments 3 and 4 directly contrast statistical averageness against familiarity through category learning procedures. Experiment 5 creates this contrast through frequency differences across stimuli. Experiments 6 and 7 investigate how the familiarity advantage found in Experiments 3-5 can be modified through fluency manipulations, independent of actual experience. Taken together, these studies suggest that category-based induction is driven largely by a familiarity heuristic.Item Role-governed categorization(2009-12) Goldwater, Micah Balser; Markman, Arthur B.; Echols, Catharine H.; Griffin, Zenzi; Loewenstein, Jeffrey; Schnyer, DavidTheories of categorization typically assume that categories are represented by some set of features that describe the properties of category members. However this view of category representation is incomplete. This dissertation lays out a framework for category representation, following Markman and Stilwell (2001), that creates a taxonomy of categories based on different components of relational structures. Relational categories are categories of entire relational systems while, role-governed categories, are represented as the roles in these systems. Lastly, thematic-relation categories group entities together that play complementary roles within a system. Four experiments are presented in support of this framework. They contrast thematic-relation categorization with role-governed categorization. Thematic-relation categorization entails categorizing objects together that play different roles within a domain, while role-governed categorization entails categorizing two entities that play the same role across domains. When the two are put in direct conflict, people prefer to form a thematic-relation category because within-domain connections are easier to find than across-domain connections. The purpose of the four experiments is to examine ways to boost the preference for role-governed categorization, thus revealing underlying processes. Here, role-governed categorization is facilitated in two ways. Experiment 1 re-frames the question of category formation as novel word extension. Natural role-governed categories have labels while thematic-relation categories do not. This pattern is reflected in the measured behavior as novel labels are extended across members of role-governed categories more readily than across members of thematic-relation categories. By claiming relational structures are critical to category representation, the framework described in this dissertation predicts that role-governed categorization and analogical reasoning share underlying mechanisms. Experiments 2-4 examine how making an analogy between the members of role-governed categories facilitates forming such categories. When making an analogy, people align the relational representations of a pair of domains, putting entities into correspondence by role, ignoring featural dissimilarities. When analogical comparison is induced, the rate of role-governed categorization is shown to double as compared to a baseline with no such analogical processes. The thesis concludes by outlining several future lines of research generated by unifying the fields of analogy and concept learning.Item The role of conceptual structure and background knowledge in category learning(Texas Tech University, 1998-12) Johnson, Matthew CarlTwo experiments were conducted in order to determine whether background information acquired by reading from text differentially influences category learning relative to when no background information is provided. Experiment 1 was a control study that compared short and long versions of text containing information that describe the characteristics of different plant features (e.g., roots, stems, leaves, and flowers) and how each is able to adapt to the characteristics of desert and mountain environments. Seventy-two participants sorted eight drawings of plants into two categories (desert and mountain plants) and read either a short list or a longer, more elaborate text describing the characteristics of plant features. Then after reading, they answered comprehension questions over the text until they mastered the information, and then they re-sorted the plants again. The results indicated that learners applied what they had read when resorting as evidenced by fewer errors relative to initial sort patterns. Experiment 2 compared the learning of linearly separable and non-linearly separable concepts for groups of participants that either received no background information (no text), read background information from a text to a high level of mastery (comprehensive text), or read at their own discretion prior to learning (available text). After participants completed one error free run through the eight training stimuli, they classified old training items and eight new transfer items. The results indicate that requiring participants to fully comprehend the text (the comprehensive text group) facilitated learning of the linearly separable concepts, but not non-linearly separable concepts. This finding is consistent with the assumption that learning is enhanced when the items to be learned do not violate background knowledge, as was the case for the comprehensive text group who learned the linearly separable concepts. In addition, transfer performance for the available and comprehensive text groups was driven more on what they had read relative to how similar the items were to past examples. However, exemplar similarity was predominantly used by all groups after learning non-linearly separable concepts. These findings were interpreted as supporting a mixed representational model that accounts for both exemplar similarity and background knowledge.