A Simple Complexity Measurement for Software Verification and Software Testing

In this paper, we used a simple metric (i.e. Lines of Code) to measure the complexity involved in software verification and software testing. The goal is then, to argue for software verification over software testing, and motivate a discussion of how to reduce the complexity involved in software verification. We propose to reduce this complexity by translating the software to a simple intermediate representation which can be verified using an efficient verifier, such as Boogie [2]

Building on CHASM: A Study of Using Counts for the Analysis of Static Models of Processes

Process modelling is gaining increasing acceptance by software engineers as a useful discipline to facilitate both process understanding and improvement activities. This position paper builds upon previous work reported at the 1997 ICSE workshop on process models and empirical studies of software engineering (Phalp and Counsell 1997). In the previous paper, we argued that simple counts could be used to support analysis of static process models. We also illustrated the idea with a coupling measure for Role Activity Diagrams, a graphical process modelling notation adapted from Petri Nets. At that time only limited empirical work had been carried out, based upon a single industrial study, where we found high levels of coupling in an inefficient process (a more thorough description may be found in (Phalp and Shepperd 1999)). We now summarise a more recent study, which uses a similar analysis of process coupling again based on simple counts. In the study, we compared ten software prototyping processes drawn from eight different organisations. We found that this approach does yield insights into process problems, which could potentially be missed by qualitative analysis alone. This is particularly so when analysing real world processes, which are frequently more complex than their text book counterparts. One notable finding was that despite differences in size and domain, role types across the organisations exhibited similar levels of coupling. Furthermore, where there were deviations in one particular role type, this led the authors to discover a relationship between project size and the coupling levels within that type of role. Given the simplicity of our approach and the complexity of many real world processes we argue that quantitative analysis of process models should be considered as a process analysis technique

Gaussian alignments in statistical translation models

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (leaves 52-53).Machine translation software has been under development almost since the birth of the electronic computer. Current state-of-the-art methods use statistical techniques to learn how to translate from one natural language to another from a corpus of hand-translated text. The success of these techniques comes from two factors: a simple statistical model and vast training data sets. The standard agenda for improving such models is to enable it to model greater complexity; however, it is a byword within the machine learning community that added complexity must be supported with more training data. Given that current models already require huge amounts of data, our agenda is instead to simplify current models before adding extensions. We present one such simplification, which results in fewer than 10% as many alignment model parameters and produces results competitive with the original model. An unexpected benefit of this technique is that it naturally gives a measure for how difficult it is to translate from one language to another given a data set. Next, we present one suggestion for adding complexity to model new behavior.by Ali Mohammad.S.M

An Exploratory Investigation on the Invasiveness of Environmental Modeling Frameworks

Environmental modeling frameworks provide an array of useful features that model developers can harness when implementing models. Each framework differs in how it provides features to a model developer via its Application Programming Interface (API). Environmental modelers harness framework features by calling and interfacing with the framework API. As modelers write model code, they make framework-specific function calls and use framework specific data types for achieving the functionality of the model. As a result of this development approach, model code becomes coupled with and dependent on a specific modeling framework. Coupling to a specific framework makes migration to other frameworks and reuse of the code outside the original framework more difficult. This complicates collaboration between model developers wishing to share model code that ma y have been developed in a variety of languages and frameworks. This paper provides initial results of an exploratory investigation on the invasiveness of environmental modeling frameworks. Invasiveness is defined as th e coupling between application (i.e., model) and framework code used to implement the model. By comparing the implementation of an environmental model across several modeling frameworks, we aim to better understand the consequences of framework design. How frameworks present functionality to modelers through APIs can lead to consequences with respect to model development, model maintenance, reuse of model code, and ultimately collaboration among model developers. By measuring framework invasiveness, we hope to provide environmental modeling framework developers and environmental modelers with valuable in formation to assist in future development efforts. Eight implementations (six framework-based) of Thornthwaite, a simple water balance model, were made in a variety of environmental modeling frameworks and languages. A set of software metrics were proposed and applied to measure invasiveness between model implementation code and framework code. The metrics produced a rank ordering of invasiveness for the framework-based implementations of Thornthwaite. We compared model invasiveness results with several popular software metrics including size in lines of code (LOC), cyclomatic complexity, and object oriented coupling. To investigate software quality implications of framework invasiveness we checked for relationships between the Chidamber and Kemerer (1994) object oriented software metrics and our framework invasiveness measures. For the six framework-based implementations of Thornthwaite we found a five-fold variation in code size (LOC). We observed up to a seven-fold variation in total cyclomatic complexity, and a two to three-fold variation in object oriented coupling. For the model implementations we found that total size, total complexity, and total coupling all had a significant positive correlation. The raw count version of our invasiveness measures correlated with application size (LOC), total cyclomatic complexity, total efferent coupling (fan out) and total afferent coupling (fan in). Large size, complexity, and high levels of coupling between units (classes, modules) in a software system are often cited in software engineering as causes of high maintenance costs due to poor understandability and flexibility of the code. This study provides initial results but further investigation is desired to evaluate the utility of our invasiveness measurement approach as well as the software quality implications of framework invasiveness

Measuring and Evaluating a Design Complexity Metric for XML Schema Documents

The eXtensible Markup Language (XML) has been gaining extraordinary acceptance from many diverse enterprise software companies for their object repositories, data interchange, and development tools. Further, many different domains, organizations and content providers have been publishing and exchanging information via internet by the usage of XML and standard schemas. Efficient implementation of XML in these domains requires well designed XML schemas. In this point of view, design of XML schemas plays an extremely important role in software development process and needs to be quantified for ease of maintainability. In this paper, an attempt has been made to evaluate the quality of XML schema documents (XSD) written in W3C XML Schema language. We propose a metric, which measures the complexity due to the internal architecture of XSD components, and due to recursion. This is the single metric, which cover all major factors responsible for complexity of XSD. The metric has been empirically and theoretically validated, demonstrated with examples and supported by comparison with other well known structure metrics applied on XML schema documents

A Complexity Measure Based on Cognitive Weights

Cognitive Informatics plays an important role in understanding the fundamental characteristics of software. This paper proposes a model of the fundamental characteristics of software, complexity in terms of cognitive weights of basic control structures. Cognitive weights are degree of difficulty or relative time and effort required for comprehending a given piece of software, which satisfy the definition of complexity. An attempt has also been made to prove the robustness of proposed complexity measure by comparing it with the other measures based on cognitive informatics

An Approach for the Empirical Validation of Software Complexity Measures

Software metrics are widely accepted tools to control and assure software quality. A large number of software metrics with a variety of content can be found in the literature; however most of them are not adopted in industry as they are seen as irrelevant to needs, as they are unsupported, and the major reason behind this is due to improper empirical validation. This paper tries to identify possible root causes for the improper empirical validation of the software metrics. A practical model for the empirical validation of software metrics is proposed along with root causes. The model is validated by applying it to recently proposed and well known metrics