This research assesses the performance of over-dispersed Poisson regression model and negative binomial model with count data. It examines the association between price plan features of mobile phone services and the number of people who adopt the plan. Mobile service data is used to estimate the model with a sample of one million customers running from February 2006 to September 2009. Under three main categories, customer type, age, and handset price, we run the model based on price plan features. Estimates are derived from the maximum likelihood estimation (MLE) method. Root mean squared error (RMSE) is used to observe the statistical fits of all the regression models. Then, we construct four estimation and holdout samples, leaving out one, three, six, and twelve months. The estimation constitutes the in-sample (IS) and the holdout represents the out-sample (OS). By estimating the IS, we predict the OS. Root mean squared error of prediction (RMSEP) is checked to see how accurate the prediction is. Results generally suggest that academic year start (AYS), seasonality, duration of months since launch of price plan (DMLP), basic fees, rate with no discount (RND), free call minutes (FCM), free data (FD), free text messaging (FTM), free perk rating (FPR), and handset support all show significant effect. The significance occurs depending on the segment. The RMSE and RMSEP show that the over-dispersed Poisson model outperforms the negative binomial model. Further implications and limitations of the results are discussed. / text

The simulation of mobile networks relies on a reliable movement generation. Random movement patterns are frequently used in simulators. In this report, the performance of the popular setdest movement generator, which is built into the ns2 open source simulator, is investigated using two statistical tests: quadrat count test and the variance to mean ratio (VMR) test. The results show a non-uniform distribution of nodes during the simulation with a bias towards placing the nodes in the center of the simulated area. We propose and implement a di erent method for random movement generation in the ns2 simulator and show that our movement generator improves the randomness of the node distribution during the simulation. The new generator was successfully tested with the ns2 simulator.

Due to more and more aggressive designs in turbomachinery, assuring the structural integrity of its components has become challenging. Also influenced by this trend is blade design, where lighter and slimmer blades, in combination with higher loading, lead to an increased risk of failure, e.g. in the form of blade vibration. Methods have been proposed to reduce vibration amplitudes for subsonic engines, but cannot directly be applied to transonic regimes due to the additional physical phenomena involved. Therefore the present work investigates numerically the influence of two methods for reducing blade vibration amplitudes in transonic turbomachines, namely varying the blade count ratio and clocking. As it is known that clocking affects the efficiency, the concurrent effects on vibration amplitudes and efficiency are analyzed and discussed in detail. For the computational investigations, the proprietary Fortran-based non-linear, viscous 3D-CFD solver VolSol is applied on two transonic compressor cases and one transonic turbine case. In order to reduce calculation time and to generate the different blade count ratios a scaling technique is applied. The first and main part of this work focuses on the influence of the reduction techniques on aerodynamic forcing. Both the change in blade count ratio and clocking position are found to have significant potential for reducing aerodynamic force amplitudes. Manipulation of the phasing of excitation sources is found herein to be a major contributor to the amplitude variation. The lowest stimulus results are achieved for de-phased excitation sources and results in multiple blade force peaks per blade passing. In the case of blade count ratio variation it was found that blockage for high blade count ratios and the change in potential field size have significant impacts on the blade forcing. For the clocking investigation, three additional operating points and blade count ratios are analyzed and prove to have an impact on the force reduction achievable by clocking. The second part of the work evaluates the influence of clocking on the efficiency of a transonic compressor. It is found that the efficiency can be increased, but the magnitude of the change and the optimal wake impingement location depend on the operating point. Moreover it is shown that optimal efficiency and aerodynamic forcing settings are not directly related. In order to approximate the range of changes of both parameters, an ellipse approximation is suggested. / <p>QC 20130911</p> / TURBOPOWER

Infection data were obtained monthly from June, 1999 to September, 2000 at the University ofKentucky dairy. Quarter foremilk samples were collected for bacteriological determination andsomatic cell counts (SCC). The Livestock Stress Index (LSI) estimated heat stress and is calculatedby combination of temperature and humidity. For uninfected quarters the geometric mean SCC was29,000 cells/ml. For infected quarters the geometric mean SCC was 213,000 cells/ml. Coagulasenegativestaphylococci (CNS) infections comprised 61 percent of the total infected quarters with ageometric mean SCC of 155,000 cells/ml. Staphylococcus aureus infected quarters had a geometricmean SCC of 680,000 cells/ml. There were no significant correlations between log SCC and LSIwhen looking at the total sample period. However, evaluating October, 1999 through September,2000, significant correlations were found for LSI and log SCC of uninfected quarters (P andlt; 0.05) and`infected quarters (P andlt; 0.0001). All correlation coefficients were less than 0.12. The results suggest nomarked changes in SCC were observed in uninfected quarters during hot summer weather. Hotsummer weather may have a minor impact on SCC in infected quarters, but the effect is variable.Thus, infection status of the mammary gland, not heat stress, is the major factor determining SCC.

This thesis examines ungrammatical article omission, and overuse of the definite article 'the' in indefinite specific context by Japanese learners of English. This is an area of English grammar that has been considered a major problem for L2 learners (e.g. Ionin, Ko & Wexler, 2004; R. Hawkins et al., 2005, 2006; Trenkic, 2007). The thesis extends the analysis of Japanese learners' interlanguage to the overuse of 'a' in indefinite specific mass contexts by these learners. A detailed analysis of DP structures in Japanese and English leads to the conclusion that Japanese learners, through their L1, are equipped with the linguistic features which map onto articles in English, even though Japanese lacks articles. The thesis examines the syntactic role of articles in rendering predicative nouns argumental (e.g. Chierchia, 1998; Longobardi, 1994) and explores the definiteness contrast marked by 'the' as opposed to 'a/ø' with singular count nouns and mass nouns (e.g. J. Hawkins, 1978) at the semantic level. Count/mass distinctions are also examined in detail (e.g. Doetjes, 1997; Jackendoff, 1992) because the 'a' versus 'Ø' contrast clearly relates this distinction. This thesis argues that, despite its lack of articles, the Japanese grammar expresses definiteness and count/mass distinctions through its classifier system. For example, different orderings of the constituents in a classifier phrase induce different interpretations as to definiteness (e.g. Kakegawa, 2004). Further, the thesis shows that some classifiers are incompatible with mass nouns, thus argue that in Japanese, as in English, nouns are associated with the features which underlie the count/mass distinction. Thus, the difficulty that Japanese learners display in mastering the grammar of articles in English is attributed to difficulties in the mapping between their syntactic and semantic underlying knowledge and the surface forms (e.g. Lardiere, 1998) rather than to the need to acquire new features or categories of syntactic or semantic knowledge as the Representational Deficit Hypothesis (R. Hawkins, 2005) claims. This proposal differs from the previous studies that assume that the relevant syntactic category is not present in the learners’ L1 thus not acquirable in the L2 (R. Hawkins et al., 2005; Trenkic, 2007). It also differs from those that suggest that, even when the learners’ L1 does not overtly realize these features (Ionin et al., 2004), the semantic features are available through universal grammar (UG). In order to examine how Japanese learners map syntactic and semantic knowledge onto the surface forms of articles in their English, data were collected via an oral production task and two types of grammaticality judgment tasks. An online judgment task was used to gather evidence for an intuitive type of knowledge of the constraints on article use, while an offline judgment task examined conscious metalinguistic knowledge of articles. Because L2 learners tend to construct and apply various metalinguistic rules as to the use of articles (Goto-Butler, 2002), the examination of both intuitive and conscious knowledge is essential for a comprehensive understanding of the development of the article system in interlanguage grammar. For the mapping of the syntactic knowledge of articles, the omission of articles by Japanese participants is investigated. The investigation focused on singular count nouns because the omission of articles with these nouns is ungrammatical in any context. It was observed that several of the Japanese participants indeed disallowed article omission for these nouns, suggesting that they had acquired the English system of mapping relevant syntactic knowledge onto the surface forms of articles. The thesis also explores the mapping of the semantic knowledge of articles by focusing on the overuse of 'the' in indefinite specific contexts. Previous studies have claimed that the overuse of 'the' is governed by the Article Choice Parameter (Ionin et al., 2004). The findings reported here confirm the tendency to overuse 'the' in indefinite specific (i.e. noteworthy (Ionin et al., 2004)) contexts. However, it was also observed that 'a' was judged acceptable in the same context. The offline grammaticality judgment task revealed that the choice of 'the' in this context may have been affected by metalinguistic knowledge. Thus, the findings are not in agreement with the hypothesis that a parameter governs the overuse of 'the' in indefinite specific contexts. Additionally, the thesis examines the overuse of 'a' in mass contexts. Though small in number, the participants who make inconsistent judgments for the same noun showed a tendency to accept the use of 'a' in specific contexts (i.e. de re specific) and reject it in non-specific contexts. It is argued that the feature [+specific] may be mapped onto 'a' in mass contexts in these learners’ grammar. Based on these findings, the thesis explores how the syntactic module and the semantic module interact with each other in L2 grammar when mapping linguistic knowledge onto surface forms. The thesis also explores the effect of metalinguistic knowledge on L2 learners’ grammaticality judgments in order to demonstrate a more comprehensive picture of article systems in interlanguage grammar.

This thesis examines ungrammatical article omission, and overuse of the definite article 'the' in indefinite specific context by Japanese learners of English. This is an area of English grammar that has been considered a major problem for L2 learners (e.g. Ionin, Ko & Wexler, 2004; R. Hawkins et al., 2005, 2006; Trenkic, 2007). The thesis extends the analysis of Japanese learners' interlanguage to the overuse of 'a' in indefinite specific mass contexts by these learners. A detailed analysis of DP structures in Japanese and English leads to the conclusion that Japanese learners, through their L1, are equipped with the linguistic features which map onto articles in English, even though Japanese lacks articles. The thesis examines the syntactic role of articles in rendering predicative nouns argumental (e.g. Chierchia, 1998; Longobardi, 1994) and explores the definiteness contrast marked by 'the' as opposed to 'a/ø' with singular count nouns and mass nouns (e.g. J. Hawkins, 1978) at the semantic level. Count/mass distinctions are also examined in detail (e.g. Doetjes, 1997; Jackendoff, 1992) because the 'a' versus 'Ø' contrast clearly relates this distinction. This thesis argues that, despite its lack of articles, the Japanese grammar expresses definiteness and count/mass distinctions through its classifier system. For example, different orderings of the constituents in a classifier phrase induce different interpretations as to definiteness (e.g. Kakegawa, 2004). Further, the thesis shows that some classifiers are incompatible with mass nouns, thus argue that in Japanese, as in English, nouns are associated with the features which underlie the count/mass distinction. Thus, the difficulty that Japanese learners display in mastering the grammar of articles in English is attributed to difficulties in the mapping between their syntactic and semantic underlying knowledge and the surface forms (e.g. Lardiere, 1998) rather than to the need to acquire new features or categories of syntactic or semantic knowledge as the Representational Deficit Hypothesis (R. Hawkins, 2005) claims. This proposal differs from the previous studies that assume that the relevant syntactic category is not present in the learners’ L1 thus not acquirable in the L2 (R. Hawkins et al., 2005; Trenkic, 2007). It also differs from those that suggest that, even when the learners’ L1 does not overtly realize these features (Ionin et al., 2004), the semantic features are available through universal grammar (UG). In order to examine how Japanese learners map syntactic and semantic knowledge onto the surface forms of articles in their English, data were collected via an oral production task and two types of grammaticality judgment tasks. An online judgment task was used to gather evidence for an intuitive type of knowledge of the constraints on article use, while an offline judgment task examined conscious metalinguistic knowledge of articles. Because L2 learners tend to construct and apply various metalinguistic rules as to the use of articles (Goto-Butler, 2002), the examination of both intuitive and conscious knowledge is essential for a comprehensive understanding of the development of the article system in interlanguage grammar. For the mapping of the syntactic knowledge of articles, the omission of articles by Japanese participants is investigated. The investigation focused on singular count nouns because the omission of articles with these nouns is ungrammatical in any context. It was observed that several of the Japanese participants indeed disallowed article omission for these nouns, suggesting that they had acquired the English system of mapping relevant syntactic knowledge onto the surface forms of articles. The thesis also explores the mapping of the semantic knowledge of articles by focusing on the overuse of 'the' in indefinite specific contexts. Previous studies have claimed that the overuse of 'the' is governed by the Article Choice Parameter (Ionin et al., 2004). The findings reported here confirm the tendency to overuse 'the' in indefinite specific (i.e. noteworthy (Ionin et al., 2004)) contexts. However, it was also observed that 'a' was judged acceptable in the same context. The offline grammaticality judgment task revealed that the choice of 'the' in this context may have been affected by metalinguistic knowledge. Thus, the findings are not in agreement with the hypothesis that a parameter governs the overuse of 'the' in indefinite specific contexts. Additionally, the thesis examines the overuse of 'a' in mass contexts. Though small in number, the participants who make inconsistent judgments for the same noun showed a tendency to accept the use of 'a' in specific contexts (i.e. de re specific) and reject it in non-specific contexts. It is argued that the feature [+specific] may be mapped onto 'a' in mass contexts in these learners’ grammar. Based on these findings, the thesis explores how the syntactic module and the semantic module interact with each other in L2 grammar when mapping linguistic knowledge onto surface forms. The thesis also explores the effect of metalinguistic knowledge on L2 learners’ grammaticality judgments in order to demonstrate a more comprehensive picture of article systems in interlanguage grammar.

This thesis examines ungrammatical article omission, and overuse of the definite article 'the' in indefinite specific context by Japanese learners of English. This is an area of English grammar that has been considered a major problem for L2 learners (e.g. Ionin, Ko & Wexler, 2004; R. Hawkins et al., 2005, 2006; Trenkic, 2007). The thesis extends the analysis of Japanese learners' interlanguage to the overuse of 'a' in indefinite specific mass contexts by these learners. A detailed analysis of DP structures in Japanese and English leads to the conclusion that Japanese learners, through their L1, are equipped with the linguistic features which map onto articles in English, even though Japanese lacks articles. The thesis examines the syntactic role of articles in rendering predicative nouns argumental (e.g. Chierchia, 1998; Longobardi, 1994) and explores the definiteness contrast marked by 'the' as opposed to 'a/ø' with singular count nouns and mass nouns (e.g. J. Hawkins, 1978) at the semantic level. Count/mass distinctions are also examined in detail (e.g. Doetjes, 1997; Jackendoff, 1992) because the 'a' versus 'Ø' contrast clearly relates this distinction. This thesis argues that, despite its lack of articles, the Japanese grammar expresses definiteness and count/mass distinctions through its classifier system. For example, different orderings of the constituents in a classifier phrase induce different interpretations as to definiteness (e.g. Kakegawa, 2004). Further, the thesis shows that some classifiers are incompatible with mass nouns, thus argue that in Japanese, as in English, nouns are associated with the features which underlie the count/mass distinction. Thus, the difficulty that Japanese learners display in mastering the grammar of articles in English is attributed to difficulties in the mapping between their syntactic and semantic underlying knowledge and the surface forms (e.g. Lardiere, 1998) rather than to the need to acquire new features or categories of syntactic or semantic knowledge as the Representational Deficit Hypothesis (R. Hawkins, 2005) claims. This proposal differs from the previous studies that assume that the relevant syntactic category is not present in the learners’ L1 thus not acquirable in the L2 (R. Hawkins et al., 2005; Trenkic, 2007). It also differs from those that suggest that, even when the learners’ L1 does not overtly realize these features (Ionin et al., 2004), the semantic features are available through universal grammar (UG). In order to examine how Japanese learners map syntactic and semantic knowledge onto the surface forms of articles in their English, data were collected via an oral production task and two types of grammaticality judgment tasks. An online judgment task was used to gather evidence for an intuitive type of knowledge of the constraints on article use, while an offline judgment task examined conscious metalinguistic knowledge of articles. Because L2 learners tend to construct and apply various metalinguistic rules as to the use of articles (Goto-Butler, 2002), the examination of both intuitive and conscious knowledge is essential for a comprehensive understanding of the development of the article system in interlanguage grammar. For the mapping of the syntactic knowledge of articles, the omission of articles by Japanese participants is investigated. The investigation focused on singular count nouns because the omission of articles with these nouns is ungrammatical in any context. It was observed that several of the Japanese participants indeed disallowed article omission for these nouns, suggesting that they had acquired the English system of mapping relevant syntactic knowledge onto the surface forms of articles. The thesis also explores the mapping of the semantic knowledge of articles by focusing on the overuse of 'the' in indefinite specific contexts. Previous studies have claimed that the overuse of 'the' is governed by the Article Choice Parameter (Ionin et al., 2004). The findings reported here confirm the tendency to overuse 'the' in indefinite specific (i.e. noteworthy (Ionin et al., 2004)) contexts. However, it was also observed that 'a' was judged acceptable in the same context. The offline grammaticality judgment task revealed that the choice of 'the' in this context may have been affected by metalinguistic knowledge. Thus, the findings are not in agreement with the hypothesis that a parameter governs the overuse of 'the' in indefinite specific contexts. Additionally, the thesis examines the overuse of 'a' in mass contexts. Though small in number, the participants who make inconsistent judgments for the same noun showed a tendency to accept the use of 'a' in specific contexts (i.e. de re specific) and reject it in non-specific contexts. It is argued that the feature [+specific] may be mapped onto 'a' in mass contexts in these learners’ grammar. Based on these findings, the thesis explores how the syntactic module and the semantic module interact with each other in L2 grammar when mapping linguistic knowledge onto surface forms. The thesis also explores the effect of metalinguistic knowledge on L2 learners’ grammaticality judgments in order to demonstrate a more comprehensive picture of article systems in interlanguage grammar.

This thesis examines ungrammatical article omission, and overuse of the definite article 'the' in indefinite specific context by Japanese learners of English. This is an area of English grammar that has been considered a major problem for L2 learners (e.g. Ionin, Ko & Wexler, 2004; R. Hawkins et al., 2005, 2006; Trenkic, 2007). The thesis extends the analysis of Japanese learners' interlanguage to the overuse of 'a' in indefinite specific mass contexts by these learners. A detailed analysis of DP structures in Japanese and English leads to the conclusion that Japanese learners, through their L1, are equipped with the linguistic features which map onto articles in English, even though Japanese lacks articles. The thesis examines the syntactic role of articles in rendering predicative nouns argumental (e.g. Chierchia, 1998; Longobardi, 1994) and explores the definiteness contrast marked by 'the' as opposed to 'a/ø' with singular count nouns and mass nouns (e.g. J. Hawkins, 1978) at the semantic level. Count/mass distinctions are also examined in detail (e.g. Doetjes, 1997; Jackendoff, 1992) because the 'a' versus 'Ø' contrast clearly relates this distinction. This thesis argues that, despite its lack of articles, the Japanese grammar expresses definiteness and count/mass distinctions through its classifier system. For example, different orderings of the constituents in a classifier phrase induce different interpretations as to definiteness (e.g. Kakegawa, 2004). Further, the thesis shows that some classifiers are incompatible with mass nouns, thus argue that in Japanese, as in English, nouns are associated with the features which underlie the count/mass distinction. Thus, the difficulty that Japanese learners display in mastering the grammar of articles in English is attributed to difficulties in the mapping between their syntactic and semantic underlying knowledge and the surface forms (e.g. Lardiere, 1998) rather than to the need to acquire new features or categories of syntactic or semantic knowledge as the Representational Deficit Hypothesis (R. Hawkins, 2005) claims. This proposal differs from the previous studies that assume that the relevant syntactic category is not present in the learners’ L1 thus not acquirable in the L2 (R. Hawkins et al., 2005; Trenkic, 2007). It also differs from those that suggest that, even when the learners’ L1 does not overtly realize these features (Ionin et al., 2004), the semantic features are available through universal grammar (UG). In order to examine how Japanese learners map syntactic and semantic knowledge onto the surface forms of articles in their English, data were collected via an oral production task and two types of grammaticality judgment tasks. An online judgment task was used to gather evidence for an intuitive type of knowledge of the constraints on article use, while an offline judgment task examined conscious metalinguistic knowledge of articles. Because L2 learners tend to construct and apply various metalinguistic rules as to the use of articles (Goto-Butler, 2002), the examination of both intuitive and conscious knowledge is essential for a comprehensive understanding of the development of the article system in interlanguage grammar. For the mapping of the syntactic knowledge of articles, the omission of articles by Japanese participants is investigated. The investigation focused on singular count nouns because the omission of articles with these nouns is ungrammatical in any context. It was observed that several of the Japanese participants indeed disallowed article omission for these nouns, suggesting that they had acquired the English system of mapping relevant syntactic knowledge onto the surface forms of articles. The thesis also explores the mapping of the semantic knowledge of articles by focusing on the overuse of 'the' in indefinite specific contexts. Previous studies have claimed that the overuse of 'the' is governed by the Article Choice Parameter (Ionin et al., 2004). The findings reported here confirm the tendency to overuse 'the' in indefinite specific (i.e. noteworthy (Ionin et al., 2004)) contexts. However, it was also observed that 'a' was judged acceptable in the same context. The offline grammaticality judgment task revealed that the choice of 'the' in this context may have been affected by metalinguistic knowledge. Thus, the findings are not in agreement with the hypothesis that a parameter governs the overuse of 'the' in indefinite specific contexts. Additionally, the thesis examines the overuse of 'a' in mass contexts. Though small in number, the participants who make inconsistent judgments for the same noun showed a tendency to accept the use of 'a' in specific contexts (i.e. de re specific) and reject it in non-specific contexts. It is argued that the feature [+specific] may be mapped onto 'a' in mass contexts in these learners’ grammar. Based on these findings, the thesis explores how the syntactic module and the semantic module interact with each other in L2 grammar when mapping linguistic knowledge onto surface forms. The thesis also explores the effect of metalinguistic knowledge on L2 learners’ grammaticality judgments in order to demonstrate a more comprehensive picture of article systems in interlanguage grammar.

This thesis examines ungrammatical article omission, and overuse of the definite article 'the' in indefinite specific context by Japanese learners of English. This is an area of English grammar that has been considered a major problem for L2 learners (e.g. Ionin, Ko & Wexler, 2004; R. Hawkins et al., 2005, 2006; Trenkic, 2007). The thesis extends the analysis of Japanese learners' interlanguage to the overuse of 'a' in indefinite specific mass contexts by these learners. A detailed analysis of DP structures in Japanese and English leads to the conclusion that Japanese learners, through their L1, are equipped with the linguistic features which map onto articles in English, even though Japanese lacks articles. The thesis examines the syntactic role of articles in rendering predicative nouns argumental (e.g. Chierchia, 1998; Longobardi, 1994) and explores the definiteness contrast marked by 'the' as opposed to 'a/ø' with singular count nouns and mass nouns (e.g. J. Hawkins, 1978) at the semantic level. Count/mass distinctions are also examined in detail (e.g. Doetjes, 1997; Jackendoff, 1992) because the 'a' versus 'Ø' contrast clearly relates this distinction. This thesis argues that, despite its lack of articles, the Japanese grammar expresses definiteness and count/mass distinctions through its classifier system. For example, different orderings of the constituents in a classifier phrase induce different interpretations as to definiteness (e.g. Kakegawa, 2004). Further, the thesis shows that some classifiers are incompatible with mass nouns, thus argue that in Japanese, as in English, nouns are associated with the features which underlie the count/mass distinction. Thus, the difficulty that Japanese learners display in mastering the grammar of articles in English is attributed to difficulties in the mapping between their syntactic and semantic underlying knowledge and the surface forms (e.g. Lardiere, 1998) rather than to the need to acquire new features or categories of syntactic or semantic knowledge as the Representational Deficit Hypothesis (R. Hawkins, 2005) claims. This proposal differs from the previous studies that assume that the relevant syntactic category is not present in the learners’ L1 thus not acquirable in the L2 (R. Hawkins et al., 2005; Trenkic, 2007). It also differs from those that suggest that, even when the learners’ L1 does not overtly realize these features (Ionin et al., 2004), the semantic features are available through universal grammar (UG). In order to examine how Japanese learners map syntactic and semantic knowledge onto the surface forms of articles in their English, data were collected via an oral production task and two types of grammaticality judgment tasks. An online judgment task was used to gather evidence for an intuitive type of knowledge of the constraints on article use, while an offline judgment task examined conscious metalinguistic knowledge of articles. Because L2 learners tend to construct and apply various metalinguistic rules as to the use of articles (Goto-Butler, 2002), the examination of both intuitive and conscious knowledge is essential for a comprehensive understanding of the development of the article system in interlanguage grammar. For the mapping of the syntactic knowledge of articles, the omission of articles by Japanese participants is investigated. The investigation focused on singular count nouns because the omission of articles with these nouns is ungrammatical in any context. It was observed that several of the Japanese participants indeed disallowed article omission for these nouns, suggesting that they had acquired the English system of mapping relevant syntactic knowledge onto the surface forms of articles. The thesis also explores the mapping of the semantic knowledge of articles by focusing on the overuse of 'the' in indefinite specific contexts. Previous studies have claimed that the overuse of 'the' is governed by the Article Choice Parameter (Ionin et al., 2004). The findings reported here confirm the tendency to overuse 'the' in indefinite specific (i.e. noteworthy (Ionin et al., 2004)) contexts. However, it was also observed that 'a' was judged acceptable in the same context. The offline grammaticality judgment task revealed that the choice of 'the' in this context may have been affected by metalinguistic knowledge. Thus, the findings are not in agreement with the hypothesis that a parameter governs the overuse of 'the' in indefinite specific contexts. Additionally, the thesis examines the overuse of 'a' in mass contexts. Though small in number, the participants who make inconsistent judgments for the same noun showed a tendency to accept the use of 'a' in specific contexts (i.e. de re specific) and reject it in non-specific contexts. It is argued that the feature [+specific] may be mapped onto 'a' in mass contexts in these learners’ grammar. Based on these findings, the thesis explores how the syntactic module and the semantic module interact with each other in L2 grammar when mapping linguistic knowledge onto surface forms. The thesis also explores the effect of metalinguistic knowledge on L2 learners’ grammaticality judgments in order to demonstrate a more comprehensive picture of article systems in interlanguage grammar.

Thesis (Ph.D.) -- University of Texas at Arlington, 2009.