Understanding students' performance in a computer-based assessment of complex problem solving: An analysis of behavioral data from computer-generated log files

Computer-based assessments of complex problem solving (CPS) that have been used in international large-scale surveys require students to engage in an in-depth interaction with the problem environment. In this, they evoke manifest sequences of overt behavior that are stored in computer-generated log files. In the present study, we explored the relation between several overt behaviors, which N = 1476 Finnish ninth-grade students (mean age = 15.23, SD = .47 years) exhibited when exploring a CPS environment, and their CPS performance. We used the MicroDYN approach to measure CPS and inspected students' behaviors through log-file analyses. Results indicated that students who occasionally observed the problem environment in a noninterfering way in addition to actively exploring it (noninterfering observation) showed better CPS performance, whereas students who showed a high frequency of (potentially unplanned) interventions (intervention frequency) exhibited worse CPS performance. Additionally, both too much and too little time spent on a CPS task (time on task) was associated with poor CPS performance. The observed effects held after controlling for students' use of an exploration strategy that required a sequence of multiple interventions (VOTAT strategy) indicating that these behaviors exhibited incremental effects on CPS performance beyond the use of VOTAT.     

Insights on the implementation of a computer-based message system

Although computer-based message systems (CBMS) have been adopted in parts of many corporations, they are still a new form of communications to many others. This paper is addressed to management and planners who may be contemplating the introduction of a CBMS into their organization. Its purpose is to present insights we gained from a case study of such an implementation in a medium-sized, multi-national firm which decided to introduce a CBMS on a company-wide basis. We present results on usage patterns, including traffic volumes, and on what motivated staff and management to adopt the use of the system, the way they used it and the effects it had on their work and their interactions with others. The paper concludes with a set of suggested implementation guidelines which flow from our experience.     

From files to data base: A tutorial

This paper aims at describing the transition procedure from conventional data files to a data base, beginning with data models of reality and ending with the data definition using the CODASYL DDL. The transition process is explained and a case study is also provided.     

Tools to incorporate some psychological and organizational issues during the development of computer-based systems

The organization, findings and outcomes of a joint industrial/academic project are described. The principal goal of the project was to develop and test some tools through which people involved in system development can incorporate explicit consideration of certain key psychological and organizational issues. Five tools developed for this purpose are outlined. These are concerned with the design of work organization, job design, the allocation of tasks between humans and computers, usability and task analysis. The use of the tools is described in a ‘live’ system development project in a large company. The authors briefly review the extent to which these tools meet a set of pre-specified requirements, compare their approach with those of Mumford (1986) and Lim et al. (1992), and make explicit what claims they are making of these tools.     

对 ArcView shapefile dBASE中空间属性数据的双向查询

当先进的空间技术使对空间数据的存储和管理成为可能时,对空间数据的存取、访问和查询已是在所难免的趋势。展示了一个在Windows CE4．0上开发的应用,它可以对Arc View shapefile的dBASE文件中空间数据和属性数据进行双向查询。     

A computer-based system for the acquisition and analysis of data from a field tillage study

A computer-based data acquisition system is described that enables both continuous real-time control of data collection from some 250 sensors deployed at a remote field site, and immediate conversion from analogue data to the required physical parameter. In addition, data analysis programs can be developed and run concurrently with data collection. Important aspects of the computer operating system are discussed, as is the overall programming strategy for a field experiment. An account is given of the control of scanning and measuring instruments (connected to the computer via a standard parallel-interface bus), and of the technique adopted for utilizing the file management software to store processed data in an easily retrievable form. A FORTRAN program to control the measurement of soil temperatures is discussed; and an assessment is given of the equipment's performance in use.     

The clair data system

The CLAIR data system consists of a series of FORTRAN IV programs and subroutines designed for the storage, retrieval, and processing of numeric and nonnumeric data. The CLAIR system in use at the University of Melbourne, in addition to the basic programs and subroutines, has a strong petrological bias, however, this reflects the interests of users and not restrictions on the CLAIR system. The types of programs and subroutines in the current CLAIR system are discussed briefly and, being on an UPDATE library, the system can be made available for use on a number of different computers. As a result of 3 years of use at the University of Melbourne, CLAIR has proved an extremely powerful system in the hands of a competent programmer, whereas in the hands of a student with little programming knowledge, it is an easily operated system.     

Keybam—a system of interactive computer programs for use with the petros petrochemical data bank

KEYBAM is a system of interactive FORTRAN IV programs for accessing and operating on major-element whole-rock chemical analyses stored in data bank PETROS. KEYBAM's capabilities include subfile creation based on user-supplied criteria, normative calculations and rock classification, graphical displays including histograms, X—Y plots, triangular plots, and various statistical analyses based on the SPSS System. We have attempted to design KEYBAM so that it is machine independent and can be used for research and teaching in petrology at most modern computer installations.     

穷举法破解EXCEL、WORD文档密码

本文讨论了如何使用VB编程，通过穷举法解除EXCEL文档和WORD文档的密码。并在破解过程中加入了中断，以方便用户随时中断破解过程。     

A step toward STEP-compatible engineering data management: the data models of product structure and engineering changes

In an iterative design process, there is a large amount of engineering data to be processed. Well-managed engineering data can ensure the competitiveness of companies in the competitive market. It has been recognized that a product data model is the basis for establishing engineering database. To fully support the complete product data representation in its life cycle, an international product data representation and exchange standard, STEP, is applied to model the representation of a product. In this paper, the architecture of an engineering data management (EDM) system is described, which consists of an integrated product database. There are six STEP-compatible data models constructed to demonstrate the integratibility of EDM system using common data modeling format. These data models are product definition, product structure, shape representation, engineering change, approval, and production scheduling. These data models are defined according to the integrated resources of STEP/ISO 10303 (Parts 41-44), which support a complete product information representation and a standard data format. Thus, application systems, such as CAD/CAM and MRP systems, can interact with the EDM system by accessing the database based on the STEP data exchange standard.     

Automatic synthesis of compression techniques for heterogeneous files

We present a compression technique for heterogeneous files, those files which contain multiple types of data such as text, images, binary, audio, or animation. The system uses statistical methods to determine the best algorithm to use in compressing each block of data in a file (possibly a different algorithm for each block). The file is then compressed by applying the appropriate algorithm to each block. We obtain better savings than possible by using a single algorithm for compressing the file. The implementation of a working version of this heterogeneous compressor is described, along with examples of its value toward improving compression both in theoretical and applied contexts. We compare our results with those obtained using four commercially available compression programs, PKZIP, Unix compress, Stufflt, and Compact Pro, and show that our system provides better space savings.     

Cognitive interference model of computer anxiety: Implications for computer-based assessment

In this paper, the cognitive interference model of computer anxiety (CIM-CA) is introduced as a theoretical framework for the assessment of computer anxiety and its effect on computer-based test (CBT) performance and test equivalence. Unlike other situation-specific anxieties, research on computer anxiety has not been founded on clear theories or models. Hence, the CIM-CA is intended as a new heuristic framework for representing the dispositions and cognitive processes that predispose individuals to react with state computer anxiety over a range of situations involving computers. In particular, the model focuses on the mediating role of negative computer thoughts on the computer anxiety–performance linkage. The CIM-CA model also provides a theoretical framework for analysing the effect of computer anxiety on CBT performance. Future research opportunities pertaining to the computer anxiety–performance linkage are discussed in the context of computerised cognitive assessment.     

Covering sharing trees: a compact data structure for parameterized verification

The control state reachability problem is decidable for well-structured infinite-state systems like (Lossy) Petri Nets, Vector Addition Systems, and broadcast protocols. An abstract algorithm that solves the problem is the backward reachability algorithm of [1, 21 ]. The algorithm computes the closure of the predecessor operator with respect to a given upward-closed set of target states. When applied to this class of verification problems, symbolic model checkers based on constraints like [7, 26 ] suffer from the state explosion problem.In order to tackle this problem, in [13] we introduced a new data structure, called covering sharing trees, to represent in a compact way collections of infinite sets of system configurations. In this paper, we will study the theoretical complexity of the operations over covering sharing trees needed in symbolic model checking. We will also discuss several optimizations that can be used when dealing with Petri Nets. Among them, in [14] we introduced a new heuristic rule based on structural properties of Petri Nets that can be used to efficiently prune the search during symbolic backward exploration. The combination of these techniques allowed us to turn the abstract algorithm of [1, 21 ] into a practical method. We have evaluated the method on several finite-state and infinite-state examples taken from the literature [2, 18 , 20 , 30 ]. In this paper, we will compare the results we obtained in our experiments with those obtained using other finite and infinite-state verification tools.     

The national coal-resources data system of the U.S. geological survey

The National Coal Resources Data System (NCRDS) was designed by the U.S. Geological Survey (USGS) to meet the increasing demands for rapid retrieval of information on coal location, quantity, quality, and accessibility. An interactive conversational query system devised by the USGS retrieves information from the data bank through a standard computer terminal. The system is being developed in two phases.Phase I, which currently is available on a limited basis, contains published areal resource and chemical data. The primary objective of this phase is to retrieve, calculate, and tabulate coal-resource data by area on a local, regional, or national scale. Factors available for retrieval include: state, county, quadrangle, township, coal field, coal bed, formation, geologic age, source and reliability of data, and coal-bed rank, thickness, overburden, and tonnage, or any combinations of variables. In addition, the chemical data items include individual values for proximate and ultimate analyses, BTU value, and several other physical and chemical tests. Information will be validated and deleted or updated as needed.Phase II is being developed to store, retrieve, and manipulate basic point source coal data (e.g., field observations, drill-hole logs), including geodetic location; bed thickness; depth of burial; moisture; ash; sulfur; major-, minor-, and trace-element content; heat value; and characteristics of overburden, roof rocks, and floor rocks. The computer system may be used to generate interactively structure-contour or isoline maps of the physical and chemical characteristics of a coal bed or to calculate coal resources.     

Observations of a firm's information processing with a data base management system

The organization in this study used all versions of IMS, from IMS 1 through IMS VS 1.01, over the period 1970–1975. During this period, the number of messages processed steadily increased from 6000 in October 1970 to a maximum in excess of 150,000 in September 1974. This volume enhancement was achieved by solving a sequence of problems concerning IMS software, data base design, or program coding. Perhaps the most important factors supporting the increase were two improvements in IMS software: one was the data base buffer pool introduced with IMS 2; the other the feature introduced with IMS VS that, unlike the previous versions, enabled the simultaneous updating of different data base segments belonging to the same type.     

Database design practices for inverted files

Database research literature has proposed many procedures, both manual and automated, for database design; selection of secondary indexes for inverted file type database management systems (DBMS) has been repeatedly addressed. The empirical study reported here indicates that practical inverted file design has been relatively unaffected by this research.This paper characterizes the actual database design process used at inverted file DBMS installations along such dimension as: types of secondary keys constructed, the individuals who make index design decisions, the decisions that are changed (and when) after the initial database implementation, the factors that are considered in indexing decisions, and the literature which is used in the process. The study shows that key selection (as one example of a design decision) is addressed by ad hoc procedures and well conceived procedures are not used. Further, the results indicate that database design is dominated by users and systems analysts, indexes are frequently changed and a wide range of database performance and convenience factors are influential in practice. The paper concludes with some recommendations for database design support tools.