A theory of regression testing for behaviourally compatible object types

A behavioural theory of object compatibility is presented, which has implications for object-oriented regression testing. The theory predicts that only certain models of state refinement yield compatible types, dictating the legitimate design styles to be adopted in object statecharts. The theory also predicts that conformity-testing using regression tests is inadequate. Functionally complete test-sets that are applied as regression tests to subtype objects are usually expected to cover the functionality of the original type, even though they are clearly not expected to cover extra functionality introduced in the subtype. However, such regression testing is proven to cover strictly less than the original state-space in the new context and so provides much weaker confidence than expected. A different retesting model is proposed, based on full automatic test regeneration from the subtype's specification. This method can guarantee equivalent levels of confidence after retesting. The behavioural conformity desired by regression testing can then be proven by verification in the theory

Motivation crowding in real consumption decisions: Who is messing with my groceries?

We present evidence of crowding out of intrinsic motivation in real purchasing decisions from a field experiment in a large supermarket chain. We compare three instruments, a label, a subsidy and a neutral price change, in their ability to induce consumers to switch from dirty to clean products. Interestingly a subsidy framed as an intervention is less effective than either a label or a neutrally framed price change. We argue that this provides a new explanation for crowding behaviour: consumers are resistant to having the line of demarcation between public and private decision making moved - in either direction

Benchmarking effectiveness for object-oriented unit testing

We propose a benchmark for object-oriented unit testing, called the behavioural response. This is a normative set of state- and equivalence partition-based test cases. Metrics are then defined to measure the adequacy and effectiveness of a test set (with respect to the benchmark) and the efficiency of the testing method (with respect to the time invested). The metrics are applied to expert manual testing using JUnit, and semi-automated testing using JWalk, testing a standard suite of classes that mimic component evolution. © 2008 IEEE

JWalk: a tool for lazy, systematic testing of java classes by design introspection and user interaction

Popular software testing tools, such as JUnit, allow frequent retesting of modified code; yet the manually created test scripts are often seriously incomplete. A unit-testing tool called JWalk has therefore been developed to address the need for systematic unit testing within the context of agile methods. The tool operates directly on the compiled code for Java classes and uses a new lazy method for inducing the changing design of a class on the fly. This is achieved partly through introspection, using Java’s reflection capability, and partly through interaction with the user, constructing and saving test oracles on the fly. Predictive rules reduce the number of oracle values that must be confirmed by the tester. Without human intervention, JWalk performs bounded exhaustive exploration of the class’s method protocols and may be directed to explore the space of algebraic constructions, or the intended design state-space of the tested class. With some human interaction, JWalk performs up to the equivalent of fully automated state-based testing, from a specification that was acquired incrementally

Parallel processing of semantics and phonology in spoken production:Evidence from blocked cyclic picture naming and EEG

Spoken language production involves lexical-semantic access and phonological encoding. A theoretically important question concerns the relative time course of these two cognitive processes. The predominant view has been that semantic and phonological codes are accessed in successive stages. However, recent evidence seems difficult to reconcile with a sequential view but rather suggests that both types of codes are accessed in parallel. Here, we used ERPs combined with the "blocked cyclic naming paradigm" in which items overlapped either semantically or phonologically. Behaviorally, both semantic and phonological overlap caused interference relative to unrelated baseline conditions. Crucially, ERP data demonstrated that the semantic and phonological effects emerged at a similar latency (similar to 180 msec after picture onset) and within a similar time window (180-380 msec). These findings suggest that access to phonological information takes place at a relatively early stage during spoken planning, largely in parallel with semantic processing

Feedback-Based Specification, Coding and Testing with JWalk

JWalk is a lazy systematic unit-testing tool for Java, which supports dynamic inference of specifications from code and systematic testing from the acquired specification. This paper describes the feedback-based development methodology that is possible using the JWalk Editor, an original Java-sensitive editor and compiler coupled to JWalk, which helps programmers to prototype Java class designs, generating novel test cases as they code. Systematic exploratory testing alerts the programmer to unusual consequences in the design; and confirmed test results become part of the evolving specification, which adapts continuously to modified classes and extends to subclasses. The cycle of coding, inferring and testing systematically exposes test cases that are often missed in other test-driven development approaches, which rely on programmer intuition to create test cases

Round table on camouflage

Research into camouflage has exploded over the last decade or so, with interdisciplinarity proving to be a key feature for progress. In our round table, we will address three main questions: (i) why are we researching camouflage; (ii) how do we research camouflage; and (iii) what is camouflage, and how do we measure it? These are really just starting points for what we hope will be an informative, interactive and wide-ranging discussion. Gibson Revisited: toward understanding sensory affordances of real-world environments Ute Leonards, School of Psychological Science, University of Bristol More than 50 years ago, JJ Gibson introduced the concept of affordances, which directly link actions to available information in our environments. Yet, even today, there is little crosstalk between visual cognition research and locomotion research, preventing us from understanding the affordances of sensory environments in real-world environments. In my talk, I will outline how following a Gibsonian approach could help us to find solutions to pressing societal issues such as understanding how the environments we create impact our health and wellbeing or how we could reduce fall risk in an ageing population. In a series of experiments, I will provide evidence of how the visual environment affects gait, even in hazard-free environments during walking on even ground—be it through the patterns on floor coverings or, more generally, the type of visual environment we are in. I will finish my talk with an outlook that goes beyond the research laboratory to modern urban design and will present a first attempt at a theoretical framework of Sustainable Urban Design informed by vision sciences

Virtual reality:a tool for investigating camouflage

Disruptive camouflage utilises high-contrast patches, typically positioned at the margins of an object to impede the detection and/or recognition of a perceiver. To date, the predominant methods for examining camouflage strategies are computer-based (i.e., detection experiments), field-based (e.g., survival analyses) and camouflage choice experiments using dynamically coloured organisms (e.g., cephalopods). Recent advances in virtual reality (VR) technology present the opportunity to create novel environments for testing camouflage theory. VR can combine the control of lab-based research with the ecological validity of field-based studies. Here, we develop an experimental paradigm that enables camouflage testing within a virtual reality environment. The environment comprised a spherical target that can be wrapped with different camouflage patterns and a domed background, upon which a natural image can be projected. Participants were positioned within the centre of the dome and were tasked with finding and shooting at targets randomly positioned across a bounded range within the environment. We manipulated the luminance contrast (0–2 steps of 2.5 L *) of disruptive and edge-enhancement (EE) components of the camouflage patterning to examine their impact on participant response time. Having high, but not extreme, contrast resulted in increased camouflage effectiveness. The EE component had no effect independently but interacted with the DC component. Specifically, when using EE alongside DC, a lower contrast EE component is more effective than a higher contrast EE component. Our results demonstrate that VR is a viable research tool for testing camouflage theory

Abstracts of Scottish Vision Group 2022 Meeting

Peer reviewedPublisher PD

Developing a collaborative framework for naturalistic visual search

While much research has investigated the mechanisms of visual search behaviour in laboratory-based computer tasks, there has been relatively little work on whether these results generalise to more naturalistic search tasks and thus how well existing theories explain real-world search behaviour. In addition, work relating to this question has often been carried out by researchers working in very different disciplines, including not just vision science but also fields such as consumer behaviour, sports science and medical science, making it more difficult to get an overview of the progress made and open questions remaining. We present findings from a systematic review of real-world visual search, showing that we can group the current literature into theoretical and applied approaches, and that there are certain well-studied topics (e.g., X-ray screening) but that there are relatively few links made across different search tasks and/or search contexts. We also present preliminary work detailing our development of a “naturalistic search task battery”, which aims to provide a suite of open source, reproducible and standardised real-world search tasks, thus enabling the generation of comparable data across multiple studies and aiding theory and modelling in this area