Manipulating the Alpha Level Cannot Cure Significance Testing

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance testing altogether. There are alternatives that address study design and sample size much more directly than significance testing does; but none of the statistical tools should be taken as the new magic method giving clear-cut mechanical answers. Inference should not be based on single studies at all, but on cumulative evidence from multiple independent studies. When evaluating the strength of the evidence, we should consider, for example, auxiliary assumptions, the strength of the experimental design, and implications for applications. To boil all this down to a binary decision based on a p-value threshold of 0.05, 0.01, 0.005, or anything else, is not acceptable.

On the Dual Nature of Transparency and Reliability: Rethinking Factors that Shape Trust in Automation

Prior literature has found that increasing system reliability and transparency can positively impact operators’ trust of automated systems; however, these factors are typically confounded. In the present study, we separated these factors by manipulating different stages of automation. Participants engaged in a simulated coffee manufacturing task using an interface with differing levels of reliability (65% or 95%) and transparency (one line or multiple lines of system display). The Human Computer Trust Scale (HCTS) and the Trust in Automated Systems Scale (TAS) were used to measure trust. When examining scores on TAS items with a positive-valence, we novelly observed that transparency interacted with reliability, such that high transparency and low reliability negatively impacted trust in the system. Alternatively, trust was not negatively affected by poor reliability when transparency was low, due to trivial cost of corrective behaviors that compensated for poor reliability and lack of system history understanding by the operators.

Catching Objects Thrown to Oneself: Testing Control Strategies for Object Interception in a Novel Domain

A considerable amount of research has been performed to determine the strategies people use to intercept moving objects. Much of this research has been done using target objects such as baseballs and Frisbees that are launched to people from distances ranging from 10 m to 50 m. This research has qualified the range of domains in which each strategy is effective, but there is still controversy regarding which strategy has the most general application. The present research sought to further reduce the range of possible domains in which these strategies work by testing object interception in a situation that had never been tested before, where people launch the target objects to themselves. A strategy based on controlling optical velocity—acting to keep the optical velocity of the object at zero—provided the best match to catcher ground movements and optical trajectories. These results suggest that control of optical velocity is currently the best explanation of effective interception of both other- and self-launched objects.

The Influence of Spatial and Feature Probability Cuing in Visual Search

Certain aspects of a visual search task, such as the location where a target often appears, are learned over time and can serve as a source of attentional guidance. An example of this implicit learning, spatial probability cuing speeds detection of targets that appear in probable locations. The current study investigated target feature probability learning and its relation to implicit spatial probability learning. Results reveal that individuals are sensitive to small changes in the spatial probability of targets, even incidentally learning moderate probabilities. However, feature-based probability differences impacted visual search times much less. Implications for these findings are discussed.

Evidence for a Positive Relationship between Working-Memory Capacity and Detection of Low-Prevalence Targets in Visual Search

Our ability to detect a target in visual search relates to the prevalence of the target, whereby rare targets are missed more than common targets. The current study sought to identify operator characteristics that could account for the higher miss rates associated with rare targets. The results found that working-memory capacity, which is strongly related to attentional control and inhibition of irrelevant information, was significantly correlated with the ability to detect low-prevalence targets. High-capacity observers also exhibited lengthened target-absent responses with rare targets, suggesting that the high-capacity observers were more persistent in their searches than others.

Receivers in American Football Use a Constant Optical Projection Plane Angle to Pursue and Catch Thrown Footballs

In the present work we test how well two interceptive strategies, which have been proposed for catching balls hit high in the air in baseball and cricket, account for receivers in American football catching footballs. This is an important test of the domain generality of these strategies as this is the first study examining a situation where the pursuer's locomotor axis is directed away from the origin of the ball, and because the flight characteristics of an American football are far different from targets studied in prior work. The first strategy is to elicit changes in the ball's lateral optical position that match changes in the vertical optical position so that the optical projection plane angle, ψ, remains constant, thus resulting in a linear optical trajectory (LOT). The second is keeping vertical optical ball velocity decreasing while maintaining constant lateral optical velocity (generalized optical acceleration cancellation, or GOAC). We found that the optical projection plane angle was maintained as constant significantly more often than maintaining vertical and lateral optical velocities as GOAC predicted. The present experiment extends previous research by showing that the constancy of ψ resulting in an LOT is used by humans pursuing American footballs and demonstrates the domain generality of the LOT heuristic.

Smiles as signals of lower status in football players and fashion models: evidence that smiles are associated with lower dominance and lower prestige

Across four studies, the current paper demonstrates that smiles are associated with lower social status. Moreover, the association between smiles and lower status appears in the psychology of observers and generalizes across two forms of status: prestige and dominance. In the first study, faces of fashion models representing less prestigious apparel brands were found to be more similar to a canonical smile display than the faces of models representing more prestigious apparel brands. In a second study, after being experimentally primed with either high or low prestige fashion narratives, participants in the low prestige condition were more likely to perceive smiles in a series of photographs depicting smiling and non-smiling faces. A third study of football player photographs revealed that the faces of less dominant (smaller) football players were more similar to the canonical smile display than the faces of their physically larger counterparts. Using the same football player photographs, a fourth study found that smiling was a more reliable indicator of perceived status-relevant personality traits than perceptions of the football players' physical sizes inferred from the photographs.

Smiles as Signals of Lower Status in Football Players and Fashion Models: Evidence That Smiles are Associated with Lower Dominance and Lower Prestige

Across four studies, the current paper demonstrates that smiles are associated with lower social status. Moreover, the association between smiles and lower status appears in the psychology of observers and generalizes across two forms of status: prestige and dominance. In the first study, faces of fashion models representing less prestigious apparel brands were found to be more similar to a canonical smile display than the faces of models representing more prestigious apparel brands. In a second study, after being experimentally primed with either high or low prestige fashion narratives, participants in the low prestige condition were more likely to perceive smiles in a series of photographs depicting smiling and non-smiling faces. A third study of football player photographs revealed that the faces of less dominant (smaller) football players were more similar to the canonical smile display than the faces of their physically larger counterparts. Using the same football player photographs, a fourth study found that smiling was a more reliable indicator of perceived status-relevant personality traits than perceptions of the football players' physical sizes inferred from the photographs.

The Influence of Perceived Task Difficulty and Importance on Automation Use

Automation use can be analyzed by looking at compliance rates (agreeing with automated alerts) and reliance rates (agreeing with automated nonalerts). The authors investigated how compliance and reliance rates in a target detection task depend on the perceived difficulty and importance of the trials and on the feedback given after each trial. Results show that focusing on trial importance significantly increased participants' compliance rates while reliance rates remained stable. When no feedback was presented, participants were more likely to comply with the automated aid in trials they perceived as difficult, but this trend reversed when importance was introduced and correlated with difficulty.

The dynamics of conditioning and extinction

Pigeons responded to intermittently reinforced classical conditioning trials with erratic bouts of responding to the conditioned stimulus. Responding depended on whether the prior trial contained a peck, food, or both. A linear persistence-learning model moved pigeons into and out of a response state, and a Weibull distribution for number of within-trial responses governed in-state pecking. Variations of trial and intertrial durations caused correlated changes in rate and probability of responding and in model parameters. A novel prediction--in the protracted absence of food, response rates can plateau above zero--was validated. The model predicted smooth acquisition functions when instantiated with the probability of food but a more accurate jagged learning curve when instantiated with trial-to-trial records of reinforcement. The Skinnerian parameter was dominant only when food could be accelerated or delayed by pecking. These experiments provide a framework for trial-by-trial accounts of conditioning and extinction that increases the information available from the data, permitting such accounts to comment more definitively on complex contemporary models of momentum and conditioning.

Perception of approaching and retreating floor-projected shapes in a large, immersive, multimedia learning environment

Perception of floor-projected moving geometric shapes was examined in the context of the Situated Multimedia Arts Learning Laboratory (SMALLab), an immersive, mixed-reality learning environment. As predicted, the projected destinations of shapes which retreated in depth (proximal origin) were judged significantly less accurately than those that approached (distal origin). Participants maintained similar magnitudes of error throughout the session, and no effect of practice was observed. Shape perception in an immersive multimedia environment is comparable to the real world. One may conclude that systematic exploration of basic psychological phenomena in novel mediated environments is integral to an understanding of human behavior in novel human-computer interaction architectures.

Evidence for axis-aligned motion bias: football axis-trajectory misalignment causes systematic error in projected final destinations of thrown American footballs

The axis-aligned motion (AAM) bias is the tendency of observers to assume that symmetric moving objects maintain axis-trajectory alignment and to bias their judgments of trajectory toward the axis when they are misaligned. We tested whether humans exhibit an AAM bias in a realistic, cue-rich, 3-D setting by examining the impact of axis-trajectory misalignment on estimates of final destinations of thrown American footballs. In experiments 1 and 2 we show that observers are significantly worse in judging destinations of footballs than those of volleyballs and basketballs. This difference in performance is due to the deviation of the football's axis from trajectory in flight, as shown by the correspondence of participants' lateral judgment error and the football's lateral axial deviation from trajectory, which was predicted by passer handedness. Nearly all animals exhibit bilateral symmetry and maintain axis-trajectory alignment during locomotion, and we argue that the AAM bias is complementary mental attunement to the natural regularity of this axis-aligned motion. Furthermore, this bias is also a prototypical example of a perceptual regularity that is a mixed blessing-advantageous in perceptual judgment tasks of axis trajectory-aligned moving entities like most living creatures, and disadvantageous in tasks demanding judgments of axis-trajectory-misaligned moving objects which are typically artifacts.