The present study examined the structural construct validity of the LoTi Digital-Age Survey, a measure of teacher instructional practices with technology in the classroom. Teacher responses (N = 2840) from across the United States were used to assess factor structure of the instrument using both exploratory and confirmatory analyses. Parallel analysis suggests retaining a five-factor solution compared to the MAP test that suggests retaining a three-factor solution. Both analyses (EFA and CFA) indicate that changes need to be made to the current factor structure of the survey. The last two factors were composed of items that did not cover or accurately measure the content of the latent trait. Problematic items, such as items with crossloadings, were discussed. Suggestions were provided to improve the factor structure, items, and scale of the survey.

No description available.

The primary goal of this study was to develop a new procedure for estimating decision consistency and accuracy indices using the bifactor and testlet response theory (TRT) models. This study is the first to investigate decision consistency and accuracy from a multidimensional perspective, and the results have shown that the bifactor model at least behaved in way that met the author's expectations and represents a potential useful procedure. The TRT model, on the other hand, did not meet the author's expectations and generally showed poor model performance. The multidimensional decision consistency and accuracy indices proposed in this study appear to provide good performance, at least for the bifactor model, in the case of a substantial testlet effect. For practitioners examining a test containing testlets for decision consistency and accuracy, a recommended first step is to check for dimensionality. If the testlets show a significant degree of multidimensionality, then the usage of the multidimensional indices proposed can be recommended as the simulation study showed an improved level of performance over unidimensional IRT models. However, if there is a not a significant degree of multidimensionality then the unidimensional IRT models and indices would perform as well, or even better, than the multidimensional models. Another goal of this study was to compare methods for numerical integration used in the calculation of decision consistency and accuracy indices. This study investigated a new method (M method) that sampled ability estimates through a Monte-Carlo approach. In summary, the M method seems to be just as accurate as the other commonly used methods for numerical integration. However, it has some practical advantages over the D and P methods. As previously mentioned, it is not as nearly as computationally intensive as the D method. Also, the P method requires large sample sizes. In addition, the P method has conceptual disadvantage in that the conditioning variable, in theory, should be the true theta, not an estimated theta. The M method avoids both of these issues and seems to provide equally accurate estimates of decision consistency and accuracy indices, which makes it a strong option particularly in multidimensional cases.

Since the popularisation of media streaming, a number of video streaming services are continually buying new video content to mine the potential profit. As such, newly added content has to be handled appropriately to be recommended to suitable users. In this dissertation, the new item cold-start problem is addressed by exploring the potential of various deep learning features to provide video recommendations. The deep learning features investigated include features that capture the visual-appearance, as well as audio and motion information from video content. Different fusion methods are also explored to evaluate how well these feature modalities can be combined to fully exploit the complementary information captured by them. Experiments on a real-world video dataset for movie recommendations show that deep learning features outperform hand crafted features. In particular, it is found that recommendations generated with deep learning audio features and action-centric deep learning features are superior to Mel-frequency cepstral coefficients (MFCC) and state-of-the-art improved dense trajectory (iDT) features. It was also found that the combination of various deep learning features with textual metadata and hand-crafted features provide significant improvement in recommendations, as compared to combining only deep learning and hand-crafted features. / Dissertation (MEng (Computer Engineering))--University of Pretoria, 2021. / The MultiChoice Research Chair of Machine Learning at the University of Pretoria / UP Postgraduate Masters Research bursary / Electrical, Electronic and Computer Engineering / MEng (Computer Engineering) / Unrestricted

No description available.

The diploma thesis focuses on impact of construction position and its impact on price of off-road transport. One of the main aims of the thesis is to assess influence of location of construction on its price and cost. Furthermore, the work aims at creating optimal procedure for processing information obtained from the budget. The diploma thesis is divided into two parts. In the theoretical part are described themes related to the given topic and in the practical part the obtained data are analyzed and subsequently processed

The content of this thesis is the application of selected statistical methods that will be used for inventory management selected companies. The practical part deals with the analysis and description of the application that will evaluate how the policy is guided by the supply company.

This work deals with an assessment and economic return on investment project. The theoretical part describes price formats, methods of drawing up an object budget, a payback period, costs and revenues matters and ways of financing construction projects. The practical part of this work focuses on acquiring costs and revenues emerged during the construction implementation and the use of the building. Costs incurred during the implementation will be obtained by means of itemized and general construction budget. Having obtained these values, there will be carried out a profit and loss account, from which a payback period will then be calculated.

With the novel data collection tools and diverse item types, computer-based assessments allow to easily obtain more information about an examinee’s response process such as response time (RT) data. This information has been utilized to increase the measurement precision about the latent ability in the response accuracy models. Van der Linden’s (2007) hierarchical speed-accuracy model has been widely used as a joint modelling framework to harness the information from RT and the response accuracy, simultaneously. The strict assumption of conditional independence between response and RT given latent ability and speed is commonly imposed in the joint modelling framework. Recently multiple studies (e.g., Bolsinova & Maris, 2016; Bolsinova, De Boeck, & Tijmstra, 2017a; Meng, Tao, & Chang, 2015) have found violations of the conditional independence assumption and proposed models to accommodate this violation by modelling conditional dependence of responses and RTs within a framework of Item Response Theory (IRT). Despite the widespread usage of Cognitive Diagnostic Models as formative assessment tools, the conditional joint modelling of responses and RTs has not yet been explored in this framework. Therefore, this research proposes a conditional joint response and RT model in CDM with an extended reparametrized higher-order deterministic input, noisy ‘and’ gate (DINA) model for the response accuracy. The conditional dependence is modelled by incorporating item-specific effects of residual RT (Bolsinova et al., 2017a) on the slope and intercept of the accuracy model. The effects of ignoring the conditional dependence on parameter recovery is explored with a simulation study, and empirical data analysis is conducted to demonstrate the application of the proposed model. Overall, modelling the conditional dependence, when applicable, has increased the correct attribute classification rates and resulted in more accurate item response parameter estimates.

The problem under investigation in this research is the development of a general approach that will establish a students knowledge level so that the student's learning can be optimized by beginning it at the most effective point. In preparation for this study, an active test with an acceptable CT3 homogeneity index was found. Two computer programs, RightOrder and MathTest, were written in Visual Basic. The latter administers the test, producing a file or responses that serves as input for the former, which performs the calculations and matrix manipulation necessary to determine the CT3 of a set of test items and construct a difficulty strata scale. The test was administered twice to the same population, the first time in the original item order. In the second administration, one item from each successive level of difficulty, beginning with the easiest, was given until the respondent answered incorrectly. Then all the remaining items were presented in order of difficulty, beginning with the easiest. The three hypothesis of this study are (a) the difficulty strata scale generated from the computerized retest, using a z-score to be determined as critical value, is congruent with that derived from the analysis done on the data of the first application of the computerized test, (b) the time spent to establish the knowledge level is shorter than the time spent taking the full test, and (c) the test, reordered according to ordering theory principles, is an accurate method of establishing a student's knowledge level.