Practical production testing of ISDN circuit boards

Classical Test Theory (CTT), also known as the true score theory, refers to the analysis of test results based on test scores. The statistics produced under CTT include measures of item difficulty, item discrimination, measurement error and test reliability. The term “Classical” is used in contrast to “Modern” test theory which usually refers to item response theory (IRT). The fact that CTT was developed before IRT does not mean that CTT is outdated or replaced by IRT. Both CTT and IRT provide useful statistics to help us analyse test data. Generally, CTT and IRT provide complementary results. For many item analyses, CTT may be sufficient to provide the information we need. There are, however, theoretical differences between CTT and IRT, and many researchers prefer IRT because of enhanced measurement properties under IRT. IRT also provides a framework that facilitates test equating, computer adaptive testing and test score interpretation. While this book devotes a large part to IRT, we stress that CTT is an important part of the methodologies for educational and psychological measurement. In particular, the exposition of the concept of reliability in CTT sets the basis for evaluating measuring instruments. A good understanding of CTT lays the foundations for measurement principles. There are other approaches to measurement such as generalizability theory and structural equation modelling, but these are not the focus of attention in this book.

Since most accelerator control system circuit boards reside in a commercial bus architecture, such as CAMAC or VMEbus, a computerized test station is needed for exercising the boards. This test station is needed for the development of newly designed prototypes, for commissioning newly manufactured boards, for diagnosing boards which have failed in service, and for long term testing of boards with intermittent failure problems. WindoWorks was created to address these needs. It is a flexible program which runs on a PC compatible computer and uses a PC to bus crate interface. WindoWorks was designed to give the user a flexible way to test circuit boards. Each test is incapsulated into a window. By bringing up several different windows the user can run several different tests simultaneously. The windows are sizable, and moveable. They have data entry boxes so that the test can be customized to the users preference. The windows can be used in conjunction with each other in order to create supertests. There are several windows which are generic. They can be used to test basic functions on any VME (or CAMAC) board. There are other windows which have been created to test specific boards. New windows for testing specific boards can be easily created by a Pascal programmer using the WindoWorks framework. >

The paper shows the possibility of Hierarchical Systems (HS) technology use in the tasks of Printed Circuit Boards (PCB) geometric design and interconnections (conductive pathways) quality testing. It gives formal description of the PCB construction and both the design and testing processes. Presented HS technology allows easy correction of interconnections topology of PCB, the mechanism of information aggregation permits reduction of computer memory, availability of coordinator allows performing decision making tasks on its layers. Possibility of HS technology realization using standard computer program and technical means is shown in the work as well.Keywordshierarchical systemscircuit boarddesign and testing

Comparison of two psychometric scaling methods for ratings of acute musculoskeletal pain

The study is aimed at describing: (1) characteristics of the items of the national examination try-out test of the accounting subject matter in the 2015/2016 academic year on classical test theory and modern test theory; and (2) classification of students’ masteries in the learning of accounting. The study is explorative research. Analyses are conducted using the classical and modern test theories for item characteristics and descriptive quantitative for students’ masteries in accounting using the test set for the national examination try-out in the 2015/2016 academic year. A total of 414 students do the Package A test. Results show that (1) based on the classical test analyses, a number of 11 items (27.5%) belong to the “easy” category, 22 items (55%) “medium” category, and 7 items (17.5%) “difficult” category allowing a total of 19 (47.5%) to be categorized as good items; meanwhile, on the modern-theory analyses, a total of 34 items (85%) belong to the “good” category. (2) Around 38% of the students have competencies of the medium and low categories. Most students have difficulty in answering questions of the higher-order thinking levels.

Owing to the slow circuit board level maintenance and fault location of wireless communications equipment, and technically demanding problems, the multi-state circuit board testing environment was establish to study the circuit board interface type, input and output signals, power supply and others. Based on the diagnostic strategies of multi-signal flow model optimization design, this paper designed multi-state detection system including automatic testing and manual testing, realizing the rapid detection and failure analysis, processing and positioning of general and special circuit boards.

This article introduces the Klasika software developed to run item and test analysis using the Classical Test Theory approach. Classical Test Theory is one of the specialized competencies and skills that undergraduate students of psychology must possess. Classical Test Theory becomes a mandatory course for all schools or departments of psychology in Indonesia. This article also provides a theoretical foundation of Classical Test Theory's essential concepts and statistical methods, specifically related to items and test statistics. The item analysis and test reliability procedures using Klasika, starting from the data preparation untill data interpretation, are explained with an empirical illustration. Finally, the analysis results using Klasika are compared with the results from Quest software to test the accuracy of the estimation results.

This study is about relations between classical test theory (CTT) and item response theory (IRT). It is shown that CTT is based on the assumption that measures are exchangeable, whereas IRT is based on conditional independence. Thus, IRT is presented as an extension of CTT, and concepts from both theories are related to one another. Furthermore, it is demonstrated that IRT can be used to provide CTT statistics in situations where CTT fails. Reliability, for instance, can be determined even though a test was not administered to the intended population.

Clinical psychologists are advised to assess clinical and statistical significance when assessing change in individual patients. Individual change assessment can be conducted using either the methodologies of classical test theory (CTT) or item response theory (IRT). Researchers have been optimistic about the possible advantages of using IRT rather than CTT in change assessment. However, little empirical evidence is available to support the alleged superiority of IRT in the context of individual change assessment. In this study, the authors compared the CTT and IRT methods with respect to their Type I error and detection rates. Preliminary results revealed that IRT is indeed superior to CTT in individual change detection, provided that the tests consist of at least 20 items. For shorter tests, however, CTT is generally better at correctly detecting change in individuals. The results and their implications are discussed.

The authors examined the in.uence of deviant scale items (i.e., items failing to adequately assess the construct of interest) on item parameter estimates of focal scale items and person parameter estimates through a comparison of item response theory (IRT) and classical test theory (CTT) methods. The authors used monte carlo methods to fully explore results found in a pilot investigation of jobattitude data. They found that graded response model item discrimination parameter estimates were robust when the number of focal items was larger than the number of deviant items, when the focal items were more discriminating than the deviant items, and when the correlation between the focal and deviant items was positive. IRT discrimination estimates were typically more robust than CTT discrimination estimates. Under extremely unfavorable conditions, however, CTT estimates were more robust than the IRT estimates. For person parameter estimates, the robustness of estimates depended primarily on the correlation of the deviant items with the focal construct. Implications are discussed for researchers employing IRT or CTT methods in scale development.

A classic topic in the fields of psychometrics and measurement has been the impact of the number of scale categories on test score reliability. This study builds on previous research by further articulating the relationship between item response theory (IRT) and classical test theory (CTT). Equations are presented for comparing the reliability and precision of scores within the CTT and IRT frameworks. This study presented new results pertaining to the relative precision (i.e., the test score conditional standard error of measurement for a given trait value) of CTT and IRT, and the new results shed light on the conditions where total scores and IRT estimates are more or less precisely measured. The relative reliability of CTT and IRT scores is examined as a function of item characteristics (e.g., locations, category thresholds, and discriminations) and subject characteristics (e.g., the skewness and kurtosis of the latent distribution). CTT total scores were more reliable when the latent distribution was mismatched with category thresholds, but the discrepancy between CTT and IRT declined as the number of scale categories increased. This article also considered the appropriateness of linear approximations of polytomous items and presented circumstances where linear approximations are viable. A linear approximation may be appropriate for items with two response options depending on the item discrimination and the match between the item location and latent distribution. However, linear approximations are biased whenever items are located in the tails of the latent distribution and the bias is larger for more discriminating items.

This paper describes research and development efforts in the application of advanced optical techniques for prognostic analysis of printed circuit boards and their components. Current methods of automated electronic testing require development of costly unique test program sets (TPSs) for each type of board, and only return information related to the current performance characteristics. The use of laser diagnostics in circuit board testing can eliminate the need for TPSs, while identifying compromises in material integrity that leads to hard and soft component failures. Additionally, they may be applied to solve instances of retest OK (RTOK) and no-fault-found events. Our investigation has focused on terahertz (T-Ray) imaging, laser acoustics, and near-infrared (NIR) laser imaging. T-Ray imaging is an emerging laser-based technology characterized by the ability to see through layers of plastic to the embedded metal traces of a circuit board or to the die of an encapsulated microchip. Laser acoustics may be applied to monitor the integrity of solder joints, and NIR laser imaging may be used to identify damage within an integrated circuit (IC). We present the results of our investigation into the combined use of these techniques for fault diagnosis, as well as their relative potential in the electronics test industry.

In this study, the researchers assessed comparability of item statistics of 2017 basic education certificate mathematics examination of National Examinations Council (NECO) through Classical Test Theory (CTT) and Item Response Theory (IRT) measurement frameworks. The study adopted instrumentation design. A 60-item NECO basic education certificate education mathematics objective test paper I was administered to 978 basic nine examinees, randomly selected from Osogbo and Olorunda Local Government Area, Osun State, Nigeria. The responses of the examinees to the test data were analysed using Marginal Maximum Likelihood Estimation of JMETRIK software.  The result showed that the test data obey the assumption of unidimensionality of 3-parameter logistic model and Classical Test Theory measurement framework deleted more items 33 (55%) compare to IRT measurement framework 12 (20%). Also, it was observed that item statistics from the two contrasting frameworks (CTT and IRT) were not comparable. Moreover, further analysis showed that there was low correlation among the item statistics index. The implication of this is that NECO should jettison the use of Classical Test Theory and embrace utilization of Item Response Theory framework during their test development and item analysis. 

A new test index is defined as the probability of obtaining two randomly selected test scores (PDTS) as statistically different. After giving a concept definition of the test index, two simulation studies are presented. The first analyzes the influence of the distribution of test scores, test reliability, and sample size on PDTS within classical test theory. The second simulation manipulates the number of items and their locations over the latent continuum for a one-parameter logistic model. In addition, comparisons of both applications on the same data are made. The discussion focuses on advantages of applying PDTS for dimensional constructs in classical test theory and item response theory, as well as the disadvantages of making no assumptions about the test score distribution. The simulation studies provide the initial findings about the PDTS under several given empirical conditions. The discussion emphasizes why and when it is useful to consider PDTS in a test description.

Despite theoretical differences between item response theory (IRT) and classical test theory (CTT), there is a lack of empirical knowledge about how, and to what extent, the IRT- and CTT-based item and person statistics behave differently. This study empirically examined the behaviors of the item and person statistics derived from these two measurement frameworks. The study focused on two issues: (a) What are the empirical relationships between IRT- and CTT-based item and person statistics? and (b) To what extent are the item statistics from IRT and those from CIT invariant across different participant samples? A large-scale statewide assessment database was used in the study. The findings indicate that the person and item statistics derived from the two measurement frameworks are quite comparable. The degree of invariance of item statistics across samples, usually considered as the theoretical superiority IRT models, also appeared to be similar for the two measurement fireworks.