Requirements for minicomputer operating systems for human experimentation and an implementation on a 4K PDP-8 computer

A programming system is described which considerably simplifies preparation and running of experiments on PDP-8 computers.     

Developing operating principles for systems change

Based on an analysis of the articles in this special issue, the authors propose five operating principles for systems change work. These principles are: clarifying the purpose of the systems change; identifying whether the change is one to an existing system or the change is to create a new system; conceptualize the work as systems change from the beginning; use an eclectic approach; and be open to opportunities that emerge while also undertaking forma analysis to identify leverage points. The authors argue that the time is now ripe to develop such principles and encourage community change agents to engage in a dialogue to explore, revise, eliminate or expand on these principles.     

Magnetic tape operating systems for the PDP-8

A magnetic tape operation system (TMS) based on Digital Equipment Corporation’s 4K disk monitor system (DMS), but reconfigured to improve speed and performance on a magnetic tape, is described. The TMS is compared in organization to the DMS configured to run from DECtape. A magnetic tape system device handler for Digital Equipment Corporation’s OS-8, to allow this operating system to be ran from magnetic tape, is included.     

A minicomputer system for multiperson computer-assisted telephone interviewing

A computer-assisted telephone interviewing (CATI) system has been developed which has new and extensive implications for almost every phase of survey research. CATI provides (1) schedule design assistance, (2) new interviewing capabilities and controls which eliminate procedural errors, (3) coding assistance, (4) sampling administration, (5) interview supervision, and (6) postinterview data processing.     

A minicomputer method for generating dichotic word pairs

A computer method is described for generating dichotic word pairs. The Purdue Laboratory system is implemented with a DEC PDP-12 computer.     

Hardware debugging for on-line psychologists

As computers become more prevalent as laboratory equipment, psychologists and graduate assistants will be more likely to be involved with interfacing the experiment to the computer. This paper presents some general ideas about the design and construction of digital computer interfaces and ways to facilitate their check-out and integration into the computer system. The suggestions center around the identification of functional modules within the interface or device from the beginning of the design process. These modules are preserved in the design and construction and are tested separately where possible. Specification of the interface signals between these functional units speeds debugging of a new device and facilitates maintenance of the device at a later date if adequately documented. It is important to ensure that these signals are readily available through test points and/or indicators. The paper suggests minimal equipment necessary to construct and debug an interface. It is suggested that an interactive construction procedure may be the most successful. The device is constructed in stages, with each part being verified as it is built, A simple interface is suggested for the beginner which gives him practice and a useful debugging aid as well.     

Motivational systems and preferences for social support strategies

The behavioral inhibition system (BIS), behavioral approach system (BAS), and fight-flight-freeze system (FFFS) are motivational systems that guide people’s behavior. Motivational systems may be relevant to contexts of interpersonal communication, specifically those requiring social support. In these situations, people express preferences for approaching versus avoiding and emotion versus problem-focused comfort. This paper links people’s preferences for supportive strategies with their motivational systems. 335 participants reported their preferences for different strategies of social support and their motivational system orientations. As expected, BAS was associated with preferences for involving, problem-focused support. BIS, BAS, and FFFS were significantly associated with emotion-focused support, and FFFS was negatively associated with comfort that downplays affect. The motivational systems interact when manifesting associations with preferences for support strategies, and the BAS reward responsiveness subscale emerged as the most influential BAS subscale. These results indicate that BIS, BAS, and FFFS influence people’s preferences in contexts of interpersonal communication.     

A minicomputer system for recording the dynamic properties of individual operant responses

A PDP-12 is used to conduct operant experiments in which peak force, duration, time integral of force, and interresponse time may each serve as the criterion response property for reinforcement, and all four properties are simultaneously recorded as dependent variables. Calibration, acquisition and control, and data analysis programs are described.     

A minicomputer program for control and data acquisition in classical conditioning

A 4K PDP-8/E computer program package has been developed to control classical conditioning procedures, to collect response data, and to extract statistical summeries. In contrast with other existing behavioral control languages geared to digital data typical of discrete operant analyses, this program distinguishes itself by its ability to retrieve and analyze the analog data arising from phasic response systems such as the rabbit’s nictitating membrane. By means of a question-and-answer Teletype conversation with the E, the program establishes trial sequence and trial spacing parameters; CS and US duration, probability, and interstimulus interval; intertrial interval fractionation for recording intertrial response frequencies; and session length. Various versions of the program exist to compute statistical properties of the analog response data, to dump detailed trial-by-trial topographies, and to attach instrumental contingencies to subtle features of the real-time analog responding.     

Differences in attentional strategies by novice and experienced operating theatre scrub nurses

This study investigated the effect of nursing experience on attention allocation and task performance during surgery. The prevention of cases of retained foreign bodies after surgery typically depends on scrub nurses, who are responsible for performing multiple tasks that impose heavy demands on the nurses' cognitive resources. However, the relationship between the level of experiences and attention allocation strategies has not been extensively studied. Eye movement data were collected from 10 novice and 10 experienced scrub nurses in the operating theater for caesarean section surgeries. Visual scanning data, analyzed by dividing the workstation into four main areas and the surgery into four stages, were compared to the optimum expected value estimated by SEEV (Salience, Effort, Expectancy, and Value) model. Both experienced and novice nurses showed significant correlations to the optimal percentage dwell time values, and significant differences were found in attention allocation optimality between experienced and novice nurses, with experienced nurses adhering significantly more to the optimal in the stages of high workload. Experienced nurses spent less time on the final count and encountered fewer interruptions during the count than novices indicating better performance in task management, whereas novice nurses switched attention between areas of interest more than experienced nurses. The results provide empirical evidence of a relationship between the application of optimal visual attention management strategies and performance, opening up possibilities to the development of visual attention and interruption training for better performance.     

Probe recall and short-term memory: Some evidence for nonlinear search strategies

Memory & Cognition - The subjects saw sequences of three, five, or seven digits. A subsequent probe test signaled subjects to respond with the item that had followed (forward probe) or preceded...     

Interaction strategies with advanced driver assistance systems

When using advanced driver assistance systems (ADAS) drivers need to calibrate their level of trust and interaction strategy to changes in the driving context and possible consequent reduction of system reliability (e.g. in harsh weather conditions). By investigating and identifying categories of drivers who choose inadequate interaction strategies, it is possible to address unsafe usage with e.g. tutoring lessons tailored to the respective driver category. This paper presents two studies investigating categories of drivers who apply different interaction strategies when using ADAS. Study I was designed as an exploratory field study with 37 participants interacting with a SAE level 2 system. For the exploratory study, it was important to observe and understand the interaction strategies in a driving context which entails the real complexity of the driving task. The experimental set-up of study II (simulator study), however, allowed to clearly interpret the interaction strategies as either calibrated or un-calibrated by varying the situational risk. Participants (N = 33) were driving in a situation where the system was either working reliably (low-risk condition) or in a situation where the system displayed repeatedly errors under harsh weather conditions (high-risk condition). Cluster analyses with the variables trust, monitoring behavior towards the system and usage behavior were performed to analyze potential categories of drivers. Extreme driver categories with interaction strategies indicative for both misuse and disuse were observed in both studies. In study I, drivers were categorized as either highly trusting attentive, moderately trusting attentive, moderately inattentive, inattentive or skeptical. In study II, drivers were categorized as either un-calibrated, calibrated, inconsistent or skeptical. Taken together, results underline the need of tutoring systems that are tailored for different driver categories.     

Receiver operating characteristics from nonhuman animals: Some implications and directions for research with humans

Reviews of signal detection have largely overlooked the research involving nonhuman animal subjects. Some of this research is presented and reanalyzed here. Plots of receiver operating characteristics show that human and nonhuman signal-detection performance is very similar. The studies emphasize the series of discriminations that comprise signal-detection tasks and illustrate the systematic effects of different methods of arranging payoffs or feedback, of the consistency of that feedback, and of the physical disparity between response alternatives. The data provide some support for recent theoretical accounts that favor a criterion location measure of isobias over the likelihood ratio, but they also suggest that more systematic work is required in this area. Overall, this research supports many contemporary views concerning signal detection, and it provides an alternative way of looking at some recurrent issues. It also suggests that extensions of signal detection to analyze data from other research paradigms require some caution, and it offers directions for complementary research with human subjects.     

A cost-benefit mechanism for selecting problem-solving strategies: Some extensions and empirical tests

Beach and Mitchell (Academy of Management Review 1978, 3, 439–449) proposed a contingency model for the selection of decision strategies in which the decision maker selected that strategy expected to result in the greatest net benefit (i.e., selection is based on a cost-benefit analysis). The perceived costs and benefits associated with each strategy are affected by various situational variables. Christensen-Szalanski (Organizational Behavior and Human Performance 1978, 22, 307–323) developed the selection mechanism in greater detail. The present paper extends that selection mechanism by proposing a set of alternative assumptions underlying the mechanism and by proposing an expanded role for the variable time in the decision strategy selection process. In addition, the present paper presents the results of a study testing certain of the proposed extensions and the effects of time constraints, task complexity, and task significance on the selection of a decision strategy.     

A minicomputer program for the resolution of response frequency and latency in classical conditioning preparations

This classical conditioning program is capable of controlling stimulus events and recording response data in experiments using the rabbit’s nictitating membrane and/or iaw-movement responses. The main features of the program, implemented on the PDP·12 computer, are the ability to resolve response latency within a 1 msec error range and to display the response topography on the computer’s cathode ray tube. The extreme accuracy in latency measurement cannot be duplicated either by conventional hand-scoring methods involving oscillographic records or by other minicomputer conditioning programs.