In Canada, as baby boomers age, there will be an increase in the percentage of seniors within the general population (Statistics Canada, 2006). Seniors often have difficulty in performing certain everyday tasks and have greater risk of having health issues. As such, it becomes increasingly important to understand factors that pose difficulty for this group of people. As people get older, many visual functions such as visual acuity, contrast sensitivity, and glare are known to deteriorate (Haegerstrom-Portnoy, 2005). However, when considering activities that aid mobility such as driving and walking, vision related variables are not the only ones that create difficulty for older individuals. A sensory variable such as attention, in conjunction with vision, has been shown in previous studies to be a good predictor of difficulties encountered by the elderly (McGwin, Owsley, & Ball, 1998; Owsley, McGwin, Sloane, Stalvey, & Wells, 2001). Moreover, inattention and distraction seem to be common causes of automobile accidents as well as falls. The work load imposed on the working memory can impact distractibility and inattention. In mobility related activities such as driving and walking, individuals perceive objects that are increasing in size. Experiments were designed to investigate the factors that affect the perception of targets that are enlarging in size. Size matching of expanding targets to a previously presented static target, was investigated in a group of younger participants with normal vision using central or peripheral vision. The results show that size estimates differ depending on whether the target appears in the central visual field or in the periphery. The participants respond faster to targets that appear in the periphery compared to those in the centre/midline. In the subsequent set of experiments we compared the performance of younger and older participants using a dual task paradigm where individuals had to perform two tasks concurrently, one of which was to match the size of an enlarging target. Attention was modulated in the dual tasks by varying the difficulty of the secondary task. It has been found that older individuals have difficulty processing multiple visual tasks or performing multiple tasks in general (Pashler, 1994a, 1994b, 1998; Verhaeghen et al., 2003). Compared to younger individuals, older individuals were found to have greater performance difficulty in the highly demanding dual tasks. These results are compared to those observed in studies of psychological refractory period effects. The differences between the young and older individuals are discussed with respect to limited capacity and bottle neck models of attention. Furthermore, eye movement measures in the dual tasks seem to provide evidence of difficulty in task switching for the older observers. The thesis also investigated the functional field of view of younger and older individuals. By assessing the functional field of view (FFOV) using a method employed earlier by Coeckelbergh et al., (2004a), significant overall age related differences were found. Multiple characteristics of what might affect the FFOV as measured by the attended field of view (AFOV) were also investigated (e.g., impact of a pop out distracter and divided attention). It was found that differences between the two age groups occurred in all conditions. The presence of irrelevant distracters had a greater impact on the older individuals compared to the younger group, whereas divided attention or the presence of the pop out distracter did not affect either age group. Attention processing seemed to be similar for both the younger and older individuals and, therefore, the differences between the age groups appear to be at a quantitative level rather than a qualitative level.

Since the mid 90s, an increasing number of researchers have adopted a sociocultural theory (SCT) of mind to investigate the social and cognitive functions of language during learner-learner interaction (Lantolf & Thorne, 2007). Researchers from an SCT perspective have identified that first languages (L1s) serve important cognitive functions (Alegría de la Colina & García Mayo, 2009; Storch & Aldosari, 2010). Swain and colleagues (Swain, 1995; Swain & Lapkin, 1995, 1998) have also illustrated that languaging, a form of verbalization, facilitates the completion of complex linguistic tasks which leads to second language (L2) development (Swain, Brooks, & Tocalli-Beller, 2002). Moreover, researchers have found that task type impacts language development (Storch & Aldosari, 2010; Storch & Wigglesworth, 2003; Swain & Lapkin, 2001). Due to the growing number of multilingual learners in the world today (Hammarberg, 2010), researchers need to expand the scope of the research to include the role(s) of native and nonnative languages on third language (L3) development. Thus, the purpose of the current multiple case study was to investigate the specific mediating functions of multilingual learners’ languages during four types of collaborative tasks and to explore the relationship between languaging and L3 development. A 16-week classroom-based study was conducted in a university French as a foreign language classroom in Mexico with four focal participants. The language produced during learner-learner interaction was examined using three types of analysis: (1) each turn was coded for language and for their specific functions; (2) each Language-Related Episode (LRE) was coded for type and for resolution; and (3) accuracy on individual tailor-made posttest items. Findings uncovered a complex picture of task type effects on the specific mediating functions of language as well as complementary functions of L1 and L3 mediation. Results from the analysis of LREs show that task type impacts the occurrence and resolution of LREs. Accuracy scores from the posttests suggest that L1 and L3 mediation promotes L3 development. Findings are in line with the focal participants’ beliefs. The findings that languages serve various social and cognitive functions during task completion are discussed in light of current ideas from an SCT perspective.

In Canada, as baby boomers age, there will be an increase in the percentage of seniors within the general population (Statistics Canada, 2006). Seniors often have difficulty in performing certain everyday tasks and have greater risk of having health issues. As such, it becomes increasingly important to understand factors that pose difficulty for this group of people. As people get older, many visual functions such as visual acuity, contrast sensitivity, and glare are known to deteriorate (Haegerstrom-Portnoy, 2005). However, when considering activities that aid mobility such as driving and walking, vision related variables are not the only ones that create difficulty for older individuals. A sensory variable such as attention, in conjunction with vision, has been shown in previous studies to be a good predictor of difficulties encountered by the elderly (McGwin, Owsley, & Ball, 1998; Owsley, McGwin, Sloane, Stalvey, & Wells, 2001). Moreover, inattention and distraction seem to be common causes of automobile accidents as well as falls. The work load imposed on the working memory can impact distractibility and inattention. In mobility related activities such as driving and walking, individuals perceive objects that are increasing in size. Experiments were designed to investigate the factors that affect the perception of targets that are enlarging in size. Size matching of expanding targets to a previously presented static target, was investigated in a group of younger participants with normal vision using central or peripheral vision. The results show that size estimates differ depending on whether the target appears in the central visual field or in the periphery. The participants respond faster to targets that appear in the periphery compared to those in the centre/midline. In the subsequent set of experiments we compared the performance of younger and older participants using a dual task paradigm where individuals had to perform two tasks concurrently, one of which was to match the size of an enlarging target. Attention was modulated in the dual tasks by varying the difficulty of the secondary task. It has been found that older individuals have difficulty processing multiple visual tasks or performing multiple tasks in general (Pashler, 1994a, 1994b, 1998; Verhaeghen et al., 2003). Compared to younger individuals, older individuals were found to have greater performance difficulty in the highly demanding dual tasks. These results are compared to those observed in studies of psychological refractory period effects. The differences between the young and older individuals are discussed with respect to limited capacity and bottle neck models of attention. Furthermore, eye movement measures in the dual tasks seem to provide evidence of difficulty in task switching for the older observers. The thesis also investigated the functional field of view of younger and older individuals. By assessing the functional field of view (FFOV) using a method employed earlier by Coeckelbergh et al., (2004a), significant overall age related differences were found. Multiple characteristics of what might affect the FFOV as measured by the attended field of view (AFOV) were also investigated (e.g., impact of a pop out distracter and divided attention). It was found that differences between the two age groups occurred in all conditions. The presence of irrelevant distracters had a greater impact on the older individuals compared to the younger group, whereas divided attention or the presence of the pop out distracter did not affect either age group. Attention processing seemed to be similar for both the younger and older individuals and, therefore, the differences between the age groups appear to be at a quantitative level rather than a qualitative level.

Research shows that policing is mostly sedentary but physically and mentally demanding tasks occur and that policing includes factors like police inherent stress which may impair the health of police officers. Research has also found that physical exercise can play an important part for coping with these negative elements associated with policing. The overall purpose of this study is to contribute knowledge about the importance of physical exercise for policemen. The study is based on five semi-structured interviews with police officer’s working with emergency response. The result shows that physical exercise had importance for the tasks performed during emergency responses, the police officer’s health as well as short- and longterm mental factors like reduced stress. The result also showed that the demands of policing had impacts on the officer’s exercise and it also demonstrated that the policemen didn’t exercise during work hours mostly due to regulations and organizational barriers.

In this thesis, we define a new problem area for assembly lines. In the literature, there are various studies on assembly line balancing, but none of them consider multi-manned tasks, task to which at least two operators have to be assigned. Two mathematical models and one constraint programming model are developed for both Type-I and Type-II ALB problems. The objective of Type-I problem is to minimize the number of stations whereas the objective of Type-II problem is to minimize the cycle time. In addition to this, valid inequalities are introduced to make models more efficient. Moreover, heuristic algorithms for both types are developed for large-sized problems. All formulations are applied to a real case study and then experimental analysis are conducted for all formulations to see the effects of problem parameters on performance measures. Exact models are compared each other and performance of heuristic algorithms are compared against the lower bounds.

This study mainly aimed at investigating the academic writing needs and writing self-efficacy beliefs of graduate students studying at an English-medium university, Ankara. Furthermore, such areas that have a crucial role in determining writing needs as the frequency of writing tasks, usefulness of written sources, perceived importance of academic writing, and role of Turkish while writing were explored. In this study, quantitative data via &ldquo / Academic Writing Needs Assessment Survey for Graduate Students&rdquo / were collected from 213 graduate students enrolled at Graduate School of Social Sciences. Descriptive statistics, exploratory factor analysis, and multiple regression analyses were employed to analyze the data. The results of descriptive statistics indicated that the graduate students need a wider vocabulary repertoire in order to cope with the challenges of academic writing and they are mostly assigned longer research papers. In addition, using journal articles published in the area of specialization during writing was the most common method and more than half of the graduate students stated that when stuck with finding the right word, they first look for a Turkish word first. The exploratory factor analysis produced two factors and the regression analyses were carried out. The results yielded that the predictors accounted for 24% of the variance in productivity-related academic writing needs, and 22% of the variance in accuracy-related academic writing needs. For the productivity-related academic writing needs, writing self-efficacy and academic status made a significant contribution and for the accuracy-related academic writing needs, writing self-efficacy and English proficiency exam score were significant.

Including domain rules and generalities (principles) in instructions for procedural tasks is believed to help learners understand the task domain (or the system), and in turn make them better able to complete tasks. However, equivocal results of prior research indicate that principles are not always beneficial. The goal of the current research was to delineate the characteristics of the conditions under which principles are useful. In two studies I investigated the impact of the timing of principle use, the method used to study the principles, and the specificity of the procedural instructions accompanying the principles. The first study showed that the timing of principle use (studying the principles before, during, or after completing training tasks) did not affect declarative (knowledge of the system) or procedural learning (troubleshooting task performance). Therefore, the commonly advocated idea that principles should be provided before task engagement was not supported. Neither was the hypothesis that using principles while solving tasks would enhance procedural learning. When learners summarized the principles, they demonstrated better declarative learning compared to when they just read the principles. Better declarative learning was associated with better procedural learning, but the relationship between understanding and using a system is likely not as direct as often assumed. In the second study declarative and procedural learning were enhanced when the principles were accompanied by general rather than detailed procedural instructions. General procedural instructions appeared to encourage task engagement and the effective use of principles although this effect was reduced if leaners were required to summarize the principles rather than simply read them. Together the results of the two studies reveal how the learning situation and instructional materials can be constructed to create conditions where principles enhance learning and subsequent performance.

Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 160 pages. / Thesis (PH.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This study describes in-class and home literacy events that occur when students work in groups to create web pages as evidence of learning the academic content that was presented within a fourth grade classroom. The constructivist approach to learning was the underpinning idea examined as well as its connection to technology and group work. Data were collected in a variety of ways to obtain a picture, as comprehensive as possible, of the oral, listening, viewing, and written on-task communication and interactions that occurred. As the in-class and home literacy events emerged, the competencies and strategies that students used while interacting with traditional text were uncovered. These events encompass the strategies that the students used after they encountered the text and had to modify it for one reason or another. / ABSTRACT: These literacy events illustrate how the Internet supports reading and writing in the elementary classroom when it is utilized as a tool for promoting instruction. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Students’ struggle with learning mathematics is often cast in a negative light. Mathematics educators and researchers, however, suggest that struggling to make sense of mathematics is a necessary component of learning mathematics with understanding. In order to investigate the possible connection between struggle and learning, this study examined students’ productive struggle as students worked on tasks of higher cognitive demand in middle school mathematics classrooms. Students’ productive struggle refers to students’ “effort to make sense of mathematics, to figure something out that is not immediately apparent” (Hiebert & Grouws, 2007, p. 287) as opposed to students’ effort made in despair or frustration. As an exploratory case study using embedded multiple cases, the study examined 186 episodes of student‐teacher interactions in order to identify the kinds and nature of student struggles that occurred in a naturalistic classroom setting as students engaged in mathematical tasks focused on proportional reasoning. The study identified the kinds of teacher responses used in the interaction with the students and the types of resolutions that occurred. The participants were 327 6th and 7th grade students and their six mathematics teachers from three middle schools located in mid‐size Texas cities. Findings from the study identified four basic types of student struggles: get started, carry out a process, give a mathematical explanation, and express misconception and errors. Four kinds of teacher responses to these struggles were identified as situated along a continuum: telling, directed guidance, probing guidance, and affordance. The outcomes of the student‐teacher interactions that resolved the students’ struggles were categorized as: productive, productive at a lower level, or unproductive. These categories were based on how the interactions maintained the cognitive level of the implemented task, addressed the externalized student struggle, and built on student thinking. Findings provide evidence that there are aspects of student‐teacher interactions that appear to be productive for student learning of mathematics. The struggle‐response framework developed in the study can be used to further examine the phenomenon of student struggle from initiation, interaction, to its resolution, and measure learning outcomes of students who experience struggle to make sense of mathematics. / text

Increasingly, predictive models are used to support routine business de- cisions and are integral to the strategic competitive business strategies for a wide range of industries. Most often, data-driven predictive models are in- duced from training data obtained through the businesss routine operations. However, recent research on policies for intelligent information acquisitions suggests that proactive acquisition of information can improve models at a lower cost. Most active information acquisition policies are accuracy centric; they aim to identify acquisitions of training data that are particularly benefi- cial for improving the predictive accuracy of a given model. In practice, however, inferences from a predictive model are often used along with inferences from other predictive models as well as constant factors to inform arbitrarily complex decisions. In this dissertation, I discuss how these settings motivate a new kind of collaborative information acquisition (CIA) policies that exploit knowledge of the decision to allow multiple predictive models to collaboratively prioritize the prospective information acquisitions, so as to best improve the decisions they inform jointly. I present a framework for CIA policies and two specific CIA policies: CIA for binary decisions (CIA-BD), and CIA for top-ranked opportu- nities in terms of expected revenue (CIA-TR). Extensive empirical evaluations of the policies on real-world data suggest that the notion of CIA policies is indeed a valuable one. In particular, I demonstrate that these two new poli- cies lead to superior decision-making performances as compared to those of alternative policies that are either decision-centric or do not allow multiple models to collaboratively prioritize acquisitions. The performance exhibited by the CIA policies suggest that these policies are able to effectively exploit knowledge of the decisions to avoid greedy improvements in accuracy of any individual model informing the decisions; instead, they promote improvements in any one or all of the models when such improvements are likely to benefit the decisions. / text