Inferences on enacted understanding: using immersive technologies to assess intuitive physical science knowledge

Purpose

This study aims to advance the proposal to use immersive virtual learning environments to stimulate and reveal deep-seated knowledge about science, giving instructors and researchers unique possibilities for assessing and identifying intuitive physical science knowledge. Aside from the ability to present rich and dynamic stimuli, these environments afford bodily enactment of people’s understanding, which draws less from declarative knowledge stores and more from everyday experiences with the physical world.

Design/methodology/approach

The authors ground their proposal in a critical review of the impact of stimulus and task characteristics of traditional physics inventories. Using a grounded theory approach, the authors present classifications and interpretations of observed bodily enactments of physics understandings in a study where participants enacted their understanding of force and motion of space in an immersive, interactive mixed reality (MR) environment.

Findings

The authors find that instances of these action categories can be interpreted as relating to underlying knowledge, often identified by other studies. The authors thus replicate a number of prior findings, which provide evidence to establish validation for using MR simulation as a tool for identifying people’s physical intuitions.

Research limitations/implications

This study targeted only a few specific physical science scenarios. Further, while a number of key insights about student knowledge came from the analysis, many of the observations are mere leads in need of further investigation and interpretation rather than core findings.

Originality/value

Immersive digital learning environments are primarily used for instruction. The authors propose to use and design them for assessment as well. This paper should prompt more research and development in this direction.

New Caledonian crows infer the weight of objects from observing their movements in a breeze

Humans use a variety of cues to infer an object's weight, including how easily objects can be moved. For example, if we observe an object being blown down the street by the wind, we can infer that it is light. Here, we tested whether New Caledonian crows make this type of inference. After training that only one type of object (either light or heavy) was rewarded when dropped into a food dispenser, birds observed pairs of novel objects (one light and one heavy) suspended from strings in front of an electric fan. The fan was either on—creating a breeze which buffeted the light, but not the heavy, object—or off, leaving both objects stationary. In subsequent test trials, birds could drop one, or both, of the novel objects into the food dispenser. Despite having no opportunity to handle these objects prior to testing, birds touched the correct object (light or heavy) first in 73% of experimental trials, and were at chance in control trials. Our results suggest that birds used pre-existing knowledge about the behaviour exhibited by differently weighted objects in the wind to infer their weight, using this information to guide their choices.

Development of visual perception of others' actions: Children's judgment of lifted weight

Humans are excellent at perceiving different features of the actions performed by others. For instance, by viewing someone else manipulating an unknown object, one can infer its weight–an intrinsic feature otherwise not directly accessible through vision. How such perceptual skill develops during childhood remains unclear. To confront this gap, the current study had children (N:63, 6–10 years old) and adults (N:21) judge the weight of objects after observing videos of an actor lifting them. Although 6-year-olds could already discriminate different weights, judgment accuracy had not reached adult-like levels by 10 years of age. Additionally, children’s stature was a more reliable predictor of their ability to read others’ actions than was their chronological age. This paper discusses the results in light of a potential link between motor development and action perception.

Prior Knowledge about Display Inversion in Biological Motion Perception

Display inversion severely impedes veridical perception of point-light biological motion (Pavlova and Sokolov, 2000 Perception & Psychophysics62 889–899; Sumi, 1984 Perception13 283–286). Here, by using a spontaneous-recognition paradigm, we ask whether prior information about display orientation improves biological motion perception. Participants were shown a set of 180° inverted point-light stimuli depicting a human walker and quadrupeds (dogs). In experiment 1, one group of observers was not aware of the orientation of stimuli, whereas the other group was told beforehand that stimuli will be presented upside down. In experiment 2, independent groups of participants informed about stimulus orientation saw the same set of stimuli, in each of which either a moving or a static background line was inserted. The findings indicate that information about display inversion is insufficient for reliable recognition of inverted point-light biological motion. Instead, prior information facilitates display recognition only when it is complemented by additional contextual elements. It appears that visual impressions from inverted point-light stimuli remain impenetrable with respect to one's knowledge about display orientation. The origins of orientation specificity in biological motion perception are discussed in relation to the recent neuroimaging data obtained with point-light stimuli and fragmented Mooney faces.

Representational momentum in children born preterm and at term

The term representational momentum (RM) refers to the idea that our memory representations for moving objects incorporate information about movement - a fact that can lead us to make errors when judging an object's location (the RM effect). In this study, we explored the RM effect in a sample of children born very prematurely and a sample born at term. Because preterm children are known to be at risk for problems with motion perception, we anticipated that they would show a weaker or absent RM effect. This prediction was confirmed. In addition, we found that, in both samples of children, 5-6year olds showed a reduced RM effect compared to 7-9year olds. These results demonstrate that the ability to represent motion information in memory shows continued development over this age range, and may help to elucidate factors contributing to problems with fine and gross motor planning and execution that have been observed in the preterm population. We propose that problems affecting the formation, maintenance, or use of predictive models, or motion extrapolation skills, may have cascading effects on the development of other abilities.

Introduction to Michotte's heritage in perception and cognition research

Several decades after Michotte's work was published, it continues to inspire current research in perception, cognition, and beyond. In this special issue we pay tribute to this heritage with a collection of empirical and theoretical papers on amodal completion and the perception of causality, two areas of research within which Michotte's work and ideas have had a lasting influence. As a background to better understand the remaining papers, we briefly sketch Michotte's life and work and the scope (in breadth and in depth) of his impact. We then review Michotte's seminal contributions to the areas covered in this special issue, some of the major research discoveries and themes in the intervening decades, and the major open questions and challenges we are still facing. We also include a sneak preview of the papers in this special issue, noting how they relate to Michotte's work and to each other. This review shows both how much influence Michotte has had on contemporary perception and cognition research, and how much important work remains to be done. We hope that the papers in this special issue will serve both to celebrate Michotte's heritage in this respect, and to inspire other investigators to continue the projects he began.

Task-Specific Knowledge of the Law of Pendulum Motion in Children and Adults

The present experiment investigated children and adults’ knowledge of the pendulum law under different task conditions. The question asked was whether adults and fourth-graders knew that the period of a pendulum is a function of pendulum length but is independent of its mass. The task was to judge the period on a rating scale (judgment task), to imagine the swinging pendulum and indicate the corresponding time interval (imagery task), or to adjust the period of a dynamically presented pendulum (perception task). Normative consideration of pendulum length as the only relevant factor was primarily found in the perception task and, for adults, in the imagery task, whereas in the judgment task, children and adults frequently considered the irrelevant dimension of mass. Most children showed poor imagery performance. Preceding adjustment (perception task) and rating (judgment task) had no differential influence on subsequent imagery performance.

Causation, causal perception, and conservation laws

We investigated the perception of causation via the ability to detect conservation violations in simple events. We showed that observers were sensitive to energy conservation violations in free-fall events. Furthermore, observers were sensitive to gradually perturbed energy dynamics in such events. However, they were more sensitive to the effect of decreasing gravity than to that of increasing gravity. Displays with decreasing gravity were the only displays in which the energy profile was dominated by (apparent) potential energy, leading to an asymmetric trajectory.

Biological motion shown backwards: the apparent-facing effect

We examined how showing a film backwards (reverse transformation) affects the visual perception of biological motion. Adults and 6-year-old children saw first a point-light quadruped moving normally as if on a treadmill, and then saw the same display in reverse transformation. For other groups the order of presentation was the opposite. Irrespective of the presentation mode (normal or reverse) and of the facing of the point-light figure (rightward or leftward), a pronounced apparent-facing effect was observed: the perceptual identification of a display was mainly determined by the apparent direction of locomotion. The findings suggest that in interpreting impoverished point-light biological-motion stimuli the visual system may neglect distortions caused by showing a film backwards. This property appears to be robust across perceptual development. Possible explanations of the apparent-facing effect are discussed.

Recognition of point-light biological motion displays by young children

We tested the ability of children 3-5 years of age to recognise biological motion displays. Children and adults were presented with moving point-light configurations depicting a walking person, four-legged animals (dogs), and a bird. Participants were able to reliably recognise displays with biological motion, but failed in the identification of a static (four consecutive frames taken from each sequence) version. The results indicate that, irrespective of the highly reduced and unusual structural information available in point-light displays, biological motion is sufficient for reliable recognition of human and non-human forms at an age as early as 3 years. Moreover, 5-year-olds exhibit the ceiling level of recognition. The findings are discussed in the context of the neuropsychological and brain mechanisms involved in biological motion perception.

Representational momentum in children: dynamic information and analogue representation

Two groups of children and a control group of adults completed a visual memory task previously shown to produce representational momentum in adults. In the task, a computer-animated target was shown moving either horizontally or vertically, and the target vanished without warning. After the target vanished, observers indicated the location at which it had vanished. Both children and adults exhibited representational momentum, i.e., indicated locations slightly beyond where the target actually disappeared, and the magnitude of representational momentum was larger for younger children than adults. Implications of the results for issues of sensitivity to dynamics and for reliance on analogue representation are discussed.

Prism adaptation to dynamic events

In the present study, we explored adaptation to prism-displaced dynamic and static events under conditions of minimal information. Many of our interactions with the world are dynamic and involve reaching for or intercepting moving objects. The consequences (or feedback) of those interactions entail the presence or absence of physical contact with the moving objects. In this study, humans learned, with only heptic feedback, to intercept optically displaced falling balls. To eliminate visual feedback, the falling balls disappeared behind an occluder (which systematically varied in size across groups) prior to either striking or missing a subject's hand. As occluder size decreased, adaptation increased. With minimum occluder sizes, the greatest adaptation occurred around the training position, and adaptation decreased as distance between training and testing positions increased. The results can best be described in terms of a generalization gradient centered around the training position. This generalization gradient was not present when subjects were trained with ecologically similar static arrays. Implications for models of adaptation are discussed.

Young children's judgments of relative mass of two objects in a head-on-collision event

The purpose in this study was to investigate the ability of young children to judge the relative mass of two objects depicted on a CRT monitor as colliding head-on with each other, and to determine which feature of a collision event they depend on for their judgments. In the first experiment it was shown that half of the 4-year-olds and most of the 5-year-olds and 6-year-olds consistently judged the slower object to be heavier when the velocities of the two objects before collision were the same and those after collision were different. In the second experiment young children's judgements of relative mass in noncollision events in which two objects only moved in opposite directions at different speeds were examined. Results showed that half of the 5-year-olds and most of the 6-year-olds tended to assume consistently that the slower object was heavier. However, the 4-year-olds did not show any clear tendency. The third experiment was planned to examine young children's judgments of relative mass in different collision events in which only the precollision velocities of two colliding objects were different: half of the 6-year-old children judged the slower object to be heavier, but the rest of them and half of the 5-year-old children consistently gave the opposite responses. These were based upon the delay between the starts of motion of the two objects. The 4-year-olds did not show any tendency, as in experiment 2. The results indicate that young children can specify the kinetic information about relative mass from the kinematics of collision events when viewing an appropriate collision event, and that both the precollision phase and the postcollision phase contribute to the judgement of relative mass.

Heuristic judgment of mass ratio in two-body collisions

The logic of judging relative mass from a two-body collision is developed from data presented by Runeson and Vedeler (1993). Data from two experiments are analyzed on a point-by-point basis, and strong support for the theory that mass-ratio judgments are mediated by separate speed and angle heuristics is shown. This analysis is accomplished by reducing the collision event to two elementary features: the presence of ricochet and the ratio of exit speeds. The heuristics that both ricochet and greater exit speed specify relative lightness are shown to explain the basic patterns of data presented by Runeson and Vedeler.

Constructing naive theories of motion on the fly

People often make erroneous predictions about the trajectories of moving objects. McCloskey (1983a, 1983b) and others have suggested that many of these errors stem from well-developed, but naive, theories of motion. The studies presented here examine the role of naive impetus theory in people's judgments of motion. Subjects with and without formal physics experience were asked to draw or select from alternatives the trajectories of moving objects that were presented in various manners. Results from two experiments indicate that both trajectory judgments and explanations were affected by specific response and display features of the problem. In addition, these data provide little evidence that naive impetus theory plays a significant role in subjects' performance; instead, they suggest that motion judgments and explanations are constructed on the fly from contextual cues and knowledge that is not necessarily naive.

Converging operations revisited: assessing what infants perceive using discrimination measures

The study of visual perception in human infants is confronted by a number of special problems arising from the inaccessibility of verbal reports. In this paper, we discuss the experimental strategy of converging operations in the context of investigating the phenomenal experience of infants. The goal of this strategy is to logically and empirically delimit alternative explanations for a given behavior. Knowledge about the mature functioning of a perceptual competence, as well as knowledge about its developmental course, constrains the selection of viable explanations, but cannot produce a unique interpretation. This goal is pursued through the implementation of an iterative strategy in which competing interpretations are tested until only one plausible alternative remains. A series of experiments investigating infants' sensitivity to biomechanical motions are reviewed as a way of illustrating how this methodology is operationalized.

The way the ball bounces: visual and auditory perception of elasticity and control of the bounce pass

Human observers may perceive not only spatial and temporal dimensions of the environment, but also dynamic physical properties that are useful for the control of behavior. A study is presented in which visual and auditory perception of elasticity in bouncing objects, which was specified by kinematic (spatiotemporal) patterns of object motion, were examined. In experiment 1, observers could perceive the elasticity of a bouncing ball and were able to regulate the impulse applied to the ball in a bounce pass. In experiments 2 and 3, it was demonstrated that visual perception of elasticity was based on relative height information, when it was available, and on the duration of a single period under other conditions. Observers did not make effective use of velocity information. In experiment 4, visual and auditory period information were compared and equivalent performance in both modalities was found. The results are interpreted as support for the view that dynamic properties of environmental events are perceived by means of kinematic information.