Demo Version of Experiment

To start a demo version of the experiment, click here.

Data

Data set information

The data set contains the following columns:

  • subj_code: a subject code
  • condition: condition variable counting the different conditions (1 to 8)
  • desktop_conf: confirmation that desktop PC was used
  • attent_conf: confirmation that subj. is willing to pay attention
  • Ysim_side: counterbalancing factor coding on which side of the screen the Y-sym. object was shown
  • test_stimulus: the test pic subjects saw
  • dv_selection: the choice subjects made (see dv_selection_rec to see what the numbers mean)
  • age: subjects’ age
  • gender: subjects’ gender
  • tech_issues: subjects report of technical issues
  • dv_selection_rec: recoded choices that subjects made
  • Transformation: condition variable coding the transformation condition
  • Side: codes the same variable as “Ysim_side”
  • selection_rec: codes the sames as “dv_selection_rec”

Analysis Script

Description of the study

To generalize our findings and to further test our theory, four replication (supplementary) experiments were conducted in which the shape of the objects was triangular instead of L-shaped. Some of these studies also employed a different response format than that of our main studies. In Supplementary Experiments~4-6 (which were set in a 3D context without manipulation, a 3D context with manipulation, and 2D context respectively), participants could choose between three answers instead of two. As before, they could say that one or the other of the new objects was emitting a different intensity of alpha rays. Additionally, they had the option to say that they were absolutely uncertain about which object was emitting a different intensity of alpha rays. We also conducted a pilot study (with \(N~=210\) subjects). The only difference was that subjects in the pilot study were asked to write short explanations of their choices.

Method

Participants

Four hundred and twenty participants (\(n~60\) per theoretically relevant condition, \(M_{age}~= 38.28\), \(SD_{age}~= 13.87\), age range \(18-87\)) were recruited via the online platform Prolific (). Inclusion criteria were: age range between 18 and 99 years old, a subject’s approval rate concerning participation in previous studies of at least 90%. To ensure that subjects could read and understand the materials, we excluded subjects who received no formal education. Participants received a link that led them directly to the online experiment, which was created with the JSPsych framework (https://www.jspsych.org/7.3/). Subjects received a monetary reward for their participation. Subjects were not informed about the hypotheses that we tested. We decided to test about half as many subjects than in our main experiments and stopped data collection after \(n~=60\) subjects per (transformation) condition.

Design, materials, and procedure

The experiment had the same seven between-subjects conditions as our other studies. Conditions differed with respect to the target geometrical transformation. A demo of the experiment can be run here.

After some general information and confirmation questions, subjects read the following scenario description:

Scientists on an extraterrestrial mission have landed on a foreign planet not so different from planet Earth. They plan to use their two robotic rovers to explore the desert in which they have landed. The rovers have a robotic arm with which they can pick up objects from the ground and turn them around for careful examination. An illustration of the two identical rovers is shown below.



If you have studied the information thoroughly, please click “Continue” to proceed.

On the next screen they were given more information about how the robotic arms work:

The robotic arm of the rovers has different joints allowing it to reach down to the ground. The arm also has a rotatable front part with a robotic claw that allows it to pick up objects and turn them in different directions. An illustration is shown below.



If you have studied the information thoroughly, please click “Continue” to proceed.

On a novel screen, subjects were shown illustrations of the robotic arms in action:

Before the scientists send the rovers into the desert, they want to check if the robotic arms are working correctly. As a test, they put their two coffee mugs on the ground and command the two robots to pick them up and move them around for a while. Below you can see pictures of this test. The first one shows the two mugs on the ground. The second picture shows that both robots successfully picked up a mug. The robots seem fit to explore the desert.

Subjects then proceeded to another screen on which the first geometric (triangular) object was shown. The text the picture they were shown are:

Shortly after the rovers had started exploring the desert, the scientists notice an unfamiliar black object lying on the ground. They command one of their two rovers to approach the object. As the rover comes closer, its radiation detector starts buzzing. It tells the scientists that the object is emitting alpha rays. They command the rover to pick the object up and move it around for a while. While the rover is still moving the object around, the scientists take a picture. Below you can see the photograph they took.



If you have studied the information thoroughly, please click “Continue” to proceed.

It was counterbalanced between subjects whether the robotic arm was holding the object from the left side or the right side. Subjects then proceeded to the test screen, where two objects were shown (the example below comes from the “size” condition):

Later on, the scientists spot two new objects lying on the ground. As their rovers approach these two novel objects, their radiation detectors show that one of these objects is emitting the same intensity of alpha rays as the initial object you have seen on the previous screen. The other object, by contrast, is emitting a different intensity of alpha rays than the initial object you’ve seen on the previous screen. The scientists command the rovers to pick the two objects up and move them around for a while. While the rovers are still moving the objects around, the scientists take a picture. Below you can see the photograph they took.

Whether the Y-Reflection object was displayed on the right or the left was counterbalanced between subjects. On the same screen below the picture, subjects were asked the following test question:

According to your intuition: Which of the two new objects above do you think is emitting the different intensity of alpha rays compared to the initial object?

They could select between three options in this study: “Rather the left object” vs. “I’m absolutely uncertain” vs. “Rather the right object”.

Subjects then provided demographic data, had the chance to report any technical issues they might have experienced, and then finished the experiment on a short debriefing screen.

We had also conducted a pilot study with half as many subjects. The pilot study was identical until after the main test question. Unlike subjects in the main study, subjects of the pilot study were asked to write a short explanation of their choice.

Results and discussion

The knitted analysis file can be accessed here. Subjects’ selections in the different transformation conditions are shown in the following graph:


The graph shows that, as predicted by the theory, the proportions of Not-Y-Reflection choices dropped in comparison to our studies without external object manipulation. However, less of a drop occurred in the “Size” and “Shape” conditions, which was also predicted.

A graph that averages over the different transformations is shown next:


The next graph shows subjects’ choices that we observed in the pilot study (\(N~= 210\)), which differed from the main study only after the main test screen:


This graph shows that the results were very similar to those of the main study. Again, the proportion of Not-Y-Reflection choices went down, but not in the Size and the Shape conditions. We therefore decided to aggregate the data from both studies. The aggregated results are shown below:

The aggregated graph averaging over the transformation conditions is shown below:

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