This study used multilevel measurement modeling to examine the differential difficulties of math and reading items for Grade 6 students participating in Ontario’s provincial assessment in 2005-2006, in relation to whether they received a setting accommodation, had a learning disability (LD), and spoke a language in addition to English. Both differences in difficulty between groups of students for all items (impact) and for individual items (differential item functioning) were examined. Students’ language backgrounds (whether they spoke a language in addition to English) were not significantly related to item difficulty. Compared to non-accommodated students with LD, math and reading items were relatively difficult for accommodated students with LD. Moreover, the difference in overall impact on math items was larger than on reading items for accommodated and non-accommodated students with LD. Overall, students without LD and who did not receive a setting accommodation outperformed students with LD and/or who received a setting accommodation as well as accommodated students without LD. It is important to note that, because this was an operational test administration, students were assigned to receive accommodations by their schools based on their individual needs. It is, therefore, not possible to separate the effect of the setting accommodation on item difficulty from the effects of other differences between the accommodated and non-accommodated groups. The differences in math and reading item difficulties between accommodated and non-accommodated students with LD may be due in part to factors such as comorbidity of LD and attention deficit hyperactivity disorder (ADHD) or a possible mismatch between the setting accommodation and the areas of disabilities. Moreover, the results of the present study support the underarousal/optimal stimulation hypothesis instead of the premise of the inhibitory control and attention for the use of setting accommodation. After controlling for the impact across all items of setting accommodation and LD, several math and reading items were found to exhibit differential item functioning (DIF). The possible sources of DIF were (1) math items that were not adherent to specific item-writing rules and (2) reading items targeting different types of comprehension. This study also found that the linguistic features of math items (total words, total sentences, average word length, monosyllabic words for math) and reading items (word frequency, average sentence length, and average words per sentence for reading) were associated with math and reading item difficulties for students with different characteristics. The total sentences and average word length in a math item as well as total words in a reading item significantly predicted the achievement gap between groups. Therefore, the linguistic features should be taken into account when assessments are developed and validated for examinees with varied characteristics.

This study used multilevel measurement modeling to examine the differential difficulties of math and reading items for Grade 6 students participating in Ontario’s provincial assessment in 2005-2006, in relation to whether they received a setting accommodation, had a learning disability (LD), and spoke a language in addition to English. Both differences in difficulty between groups of students for all items (impact) and for individual items (differential item functioning) were examined. Students’ language backgrounds (whether they spoke a language in addition to English) were not significantly related to item difficulty. Compared to non-accommodated students with LD, math and reading items were relatively difficult for accommodated students with LD. Moreover, the difference in overall impact on math items was larger than on reading items for accommodated and non-accommodated students with LD. Overall, students without LD and who did not receive a setting accommodation outperformed students with LD and/or who received a setting accommodation as well as accommodated students without LD. It is important to note that, because this was an operational test administration, students were assigned to receive accommodations by their schools based on their individual needs. It is, therefore, not possible to separate the effect of the setting accommodation on item difficulty from the effects of other differences between the accommodated and non-accommodated groups. The differences in math and reading item difficulties between accommodated and non-accommodated students with LD may be due in part to factors such as comorbidity of LD and attention deficit hyperactivity disorder (ADHD) or a possible mismatch between the setting accommodation and the areas of disabilities. Moreover, the results of the present study support the underarousal/optimal stimulation hypothesis instead of the premise of the inhibitory control and attention for the use of setting accommodation. After controlling for the impact across all items of setting accommodation and LD, several math and reading items were found to exhibit differential item functioning (DIF). The possible sources of DIF were (1) math items that were not adherent to specific item-writing rules and (2) reading items targeting different types of comprehension. This study also found that the linguistic features of math items (total words, total sentences, average word length, monosyllabic words for math) and reading items (word frequency, average sentence length, and average words per sentence for reading) were associated with math and reading item difficulties for students with different characteristics. The total sentences and average word length in a math item as well as total words in a reading item significantly predicted the achievement gap between groups. Therefore, the linguistic features should be taken into account when assessments are developed and validated for examinees with varied characteristics.

This thesis presents content-related and construct-related validity evidence for science sub-tests within Student Selection Test (SST) in Turkey via underlying the content, cognitive processes, item characteristics, factorial structure, and group differences based on high school type. A total number of 126,245 students were present in the research from six type of school in the data of SST 2006. Reliability Analysis, Item Analysis, Principle Component Analysis (PCA) and one-way ANOVA have been carried out to evaluate the content-related and construct-related evidence of validity of SST. SPSS and ITEMAN programs were used to conduct the above-mentioned analyses. According to the results of content analysis, science items in the SST 2006 found to be measuring various cognitive processes under knowledge, understanding and problem solving cognitive domains. Those items loaded under three factors according to PCA findings which were measuring very close dimensions. Moreover, a threat to validity was detected via one-way ANOVA due to significant mean difference across high school types.

The importance of learning mathematics and using it in daily life is obvious. On the other hand, the results from many national and international assessment studies show that the achievement of Turkish students are very far away from the bare minimum performance. However, in the measurement and evaluation procedures of both primary and secondary educational system, there is a lack of identification of this &ldquo / bare minimum&rdquo / or qualitative and clear descriptors for performance levels. A great importance is dedicated to the national exam results expressed in percentage terms of the correct responses, or in total score points in weighted scale scores, but there is still no system of presenting to students their scores with descriptions of these scores in terms of levels of skills that they did or did not reach. Therefore, this study has aimed to identify the knowledge and skills required for different performance levels defined by setting cut points for the results of a 4th grade mathematics achievement test. The test was conducted in 2007-2008 academic year with 269 fourth grade students in eight different private primary schools in Istanbul. Then, in 2008-2009 academic year, a group of ten teachers of mathematics and assessment experts took part in the study for identifying the performance level descriptors for 4th grade mathematics performance. Two different methods of standard setting were used. One of the methods was based on the oneparameter model of Item Response Theory (IRT) and mostly named as Bookmark Method. The method depended on the statistical identification of the cut points on the scale for performance levels such as Below Basic, Basic, Proficient, and Advanced. The other method was a judgmental method which required the participant teachers to classify the item as carrying the characteristics of performance levels, again, as Below Basic, Basic, Proficient, and Advanced. The study revealed that the item mappings from two methods were congruent to each other. There was a hierarchical ordering in terms of skills among the performance levels. Also, the results demonstrated that understanding and computation skills were heavily characteristics of Below Basic and Basic levels, whereas, problem solving skill was reached by the students of Proficient and Advanced levels.

The Rasch model was employed to analyze the psychometric properties of a diagnostic reading assessment and then create five short forms (n = 10, 16, 22, 28, 34 items) with an optimal test information function. The goal was to develop a universal screening measure that second grade teachers can use to identify advanced and at-risk readers to enhance Response-to-Intervention frameworks. These groups were targeted because both will need differentiated instruction in order to improve reading skills. The normative dataset of a national reading test developed with classical test theory methods was used to estimate person and item parameters. The measurement precision and classification accuracy of each short form was evaluated with the second grade students in the normative sample. Compared with full bank scores, all short forms produced highly correlated scores. The degree to which each short form identified exceptional readers was also analyzed. In consideration of classification accuracy and time-efficiency, the findings were most robust for the 10-item form. / text

This paper explores how known machine learning techniques can be applied in unique ways to simplify software and therefore dramatically increase its usability. As software has increased in popularity, its complexity has increased in lockstep, to a point where it has become burdensome. By shifting the focus from the software to the user, great advances can be achieved by way of simplification. The example problem used in this report is well known: suggest local dining choices tailored to a specific person based on known habits and those of similar people. By analyzing past choices and applying likely probabilities, assumptions can be made to reduce user interaction, allowing the user to realize the benefits of the software faster and more frequently. This is accomplished with Java Servlets, Apache Mahout machine learning libraries, and various third party resources to gather dimensions on each recommendation. / text

Despite the importance of anxiety measuring tools, there is no published data on the factor analytic structure of the Multidimensional Anxiety Scale for Children (MASC) in South African adolescents. The present study was an attempt to examine the factor structure of the MASC in South African adolescents, the factor structure equivalence for boys and girls and the correlation between MASC scores and scores on the Child Trauma Questionnaire (CTQ), Child PTSD Checklist Score, and the Beck Depression Inventory (BDI) to establish whether the MASC distinguishes between anxiety and other constructs. Available literature indicates that the MASC is invariant across gender and age and it shows excellent internal reliability and test-retest reliability (March Parker, Sullivan, Stallings & Comers, 1997). The MASC appears to measure separate dimensions of anxiety, which in turn makes it ideally suited to discriminate patterns of anxiety in children with anxiety disorders (Rynn et al., 2005). The MASC also correlates well with other measures of anxiety (Revised Children's Manifest Anxiety Scale [RCMAS] and Screen of Child Anxiety Related Emotional Disorders [SCARED]), less so with measures of depression (Children's Depression Inventory [CDI:]) and not at all with measures of disruptive behaviour (March et al., 1997; Muris, Merckelbach, Ollendick & King, 2002). Several studies across the world have confirmed the four-factor structure of the MASC and found its subscales to be reliable in several studies across the world (Olason, Sighvatsson & Smari, 2004; Rynn et al., 2005). A sample of 1078 grade 10 adolescents was selected to participate in this study. The adolescents were from nine different schools, representative of the socio-economic status and ethnic diversity of the region in the Cape Town metropole (South Africa). Principal Components Confirmatory Factor Analysis was conducted on MASC scores using a varimax rotation. Item bias analysis were used to determine gender equivalence and Pearson's correlation statistics were used to explore the correlation of MASC scores to CTQ, BDI, and Child PTSD Checklist scores. The results of the study confirm the MASC four-factor structure and its subscales were found to be reliable. The MASC performed the best out of four scales measuring anxiety or depression. Analysis showed that the four-factor structure applies equally well for males and females. Younger adolescents scored higher than older adolescents on the MASC total scale and no differences on the MASC total scale were found when comparisons of race were made. Item bias analysis showed no statistically or practically significant eta-squared (IJ') value, indicating no gender bias. In general, results in this sample show that the characteristics of the MASC are similar to the original factor structure found by March et al. (1997). The MASC appears to measure separate dimensions of anxiety, which in turn should make it ideally suited to discriminate patterns of anxiety in subgroups of children with anxiety disorders. It can be concluded that the MASC shows to be a valid and reliable measure of anxiety for South African adolescents. It can be recommended that the MASC is a clinically useful and reliable self-report scale for assessing anxiety in children and adolescents. / Thesis (M.A. (Clinical Psychology))--North-West University, Potchefstroom Campus, 2007.

In an ever-changing world, people are constantly faced with the challenge of simultaneously managing multiple roles in their work as well as their home-sphere. It therefore becomes increasingly important to maintain a balance in these two life spheres. Unfortunately, a gap exists between the positive and negative side of work-home balance as most research focuses on the negative side. Recently, a much needed instrument was develop in the Netherlands, namely the Survey Work-Home Interaction - Nijmegen (SWING), which measures both the direction of influence (work→home and vice versa) and the quality of influence (negative vs. positive). The objectives of this study were to validate the Survey Work-Home Interaction - Nijmegen (SWING) for workers of the earthmoving equipment industry in a South African context, to determine its construct equivalence and bias for different language groups, and to determine differences regarding work-home interaction between different demographic groups. A cross-sectional survey design was used. Random samples (n = 330) were taken of workers in the earthmoving equipment industry across South Africa. The SWING and a biographical questionnaire were administered. Item bias analyses, exploratory factor analysis, Cronbach alpha coefficients, MANOVAs, ANOVAs and T-tests were used to analyse the data. Exploratory factor analysis showed that the SWING consists of four factors, namely Negative Work-Home Interference, Negative Home-Work Interference, Positive Work-Home Interference and Positive Home-Work Interference. All four factors showed acceptable internal consistencies. No evidence was found for uniform or non-uniform bias of the items of the SWING for different language groups. Exploratory factor analysis with target rotations confirmed the construct equivalence of the work-home interface construct. There were also no differences regarding work-home interaction between different demographic groups, except for a practically significant difference (medium effect) between males and females with respect to negative Work-Home Interaction levels. Recommendations were made for further research. / Thesis (M.Com. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2005.

The development and application of inventory models for deteriorating items is one of the main concerns of the experts in the domain, since the number and variety of deteriorating products are dramatically increasing. One of the major gaps in the deteriorating inventories literature is that researchers have not paid enough attention to two important features in their models: i) Considering stochastic conditions; especially stochastic lead time is almost overlooked since makes the mathematical challenges complicated, ii) designing innovative inventory policies by taking into account the environmental issues and particularly the CO2 emission as a new objective in a multi-objective framework that is quite new. In this thesis, we study replenishment policy for deteriorating products under stochastic conditions in form of three different problem areas. In the first one, we develop a continuous (r,Q) inventory model for a retailer that offers a deteriorating product by considering infinite planning horizon, stochastic lead time, constant demand rate and backordered shortages. For modeling the deterioration process, a non-linear holding cost is defined. Taking into consideration the stochastic lead time as well as a non-linear holding cost makes the mathematical model more complex. We therefore customize the proposed model for a uniform distribution function that could be tractable to solve optimally by an exact approach. In second problem, we study the strategy of pooling lead time risks by splitting replenishment orders among multiple suppliers simultaneously for a retailer that sells a deteriorating product. Finally, in the last problem, we consider inventory and transportation costs, as well as the environmental impacts in a centralized supply chain by taking into account uncertain demand and partial backordered shortages. In order to deal with demand uncertainty, a two stage stochastic programming approach is taken. Then, by considering transportation vehicles capacity, we develop a mixed integer mathematical model. In this way, the best transportation vehicles and replenishment policy are determined by finding a balance between financial and environmental criteria. A numerical example from the real world is also presented to show the applicability and effectiveness of the proposed model.

Darbo objektas yra lietuvių kalbos samplaikos, apibrėžiamos kaip dvižodžiai ar ilgesni iš kaitomų ir nekaitomų žodžių sudaryti stabilieji junginiai, sudarantys vientisos reikšmės leksinį vienetą, kuris dažniausiai vartojamas nesavarankiškos (tarnybinės) kalbos dalies funkcija. Disertacijos tyrimo tikslas – ištirti lietuvių kalbos samplaikų, kaip leksinio vieneto, pasižyminčio formos ir turinio stabilumu, autonomiškumą. Darbo šaltiniai: neanotuotas Dabartinės lietuvių kalbos tekstynas, morfologiškai anotuotas lietuvių kalbos tekstynas ir lygiagretusis vokiečių–lietuvių kalbų tekstynas. Darbo metodai: aprašomasis metodas, tekstynų lingvistikos metodas, statistiniai metodai, gretinamasis metodas. Ginamieji teiginiai: 1. Remiantis išplėstąja frazeologijos samprata, samplaikos yra sustabarėjusių kalbos vienetų tipas, laikomas frazeologijos objektu nuo tada, kai tekstynų analize įrodytas šių junginių dažnumas ir vartojimo pastovumas. 2. Samplaikų stabilumas yra nevienodas. Samplaikų dėmenų traukos įverčio ir morfologinės paradigmos nuokrypio tyrimas rodo, kad samplaikų stabilumo laipsnį lemia samplaikų sandara. 3. Samplaikų kontekstui būdingas stabilumas arba kintamumas. Stabilesnių samplaikų kontekstas kintamas, todėl jos yra autonomiškesnės. Mažesniu stabilumu pasižyminčios samplaikos, kurių kontekstas labiau apibrėžtas, yra ne tokios autonomiškos. 4. Autonomiškesnės samplaikos labiau linkusios būti vertimo vienetais nei mažiau autonomiškos. Kuo samplaika autonomiškesnė, tuo... [toliau žr. visą tekstą] / The object of the study is multi-word lexemes (samplaikos in Lithuanian), defined as combinations composed of two or more inflective or non-inflective parts of speech, grammatically and semantically perceived as one unit. The goal of the dissertation is to investigate the autonomy of multi-word lexemes in the Lithuanian language. Two monolingual corpora (the non-annotated Corpus of the Contemporary Lithuanian Language and the morphologically annotated Lithuanian language corpus) and the parallel German-Lithuanian corpus have been used for the extraction and the analysis of data. Several research methods have been applied: descriptive, corpus-based, statistical, and contrastive. The statements to be defended are as follows: 1. According to the broad conception of phraseology, multi-word lexemes are a subtype of multi-word units. They are considered to be an object of phraseology, since their frequency and fixedness have been confirmed by corpus analysis. 2. There are variations in the degree of fixedness of multi-word lexemes. The analysis of collocation strength between the elements of multi-word lexemes and of deviations in morphological paradigm indicates that the degree of fixedness of multi-word lexemes is largely determined by their composition. 3. The context of multi-word lexemes is characterized by stability or variability. The context of more stable multi-word lexemes is variable, which determines their greater autonomy. Less stable multi-word lexemes that occur in... [to full text]