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

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, \(M_{age}~= 38.35\), \(SD_{age}~= 12.61\), age range \(18-73\)) 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 start exploring their surroundings and walk through a desert. They soon notice an unfamiliar black object (below you can see the photograph they took). While approaching it, their radiation detector starts buzzing. It tells the scientists that the object is emitting alpha rays.



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

They then proceeded to the test screen on which two novel objects were presented. One was always a Y-Reflection of the initial object and the other was selected based on the seven different transformation conditions. Below is an example of the “size” condition.

Later on, the scientists arrive in front of two new objects (below you can see the photograph they took). One of these objects is emitting the same intensity of alpha rays as the 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.

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.

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 and despite the third choice option, most subjects in most condition selected the Not-Y-Reflection object. As in our Experiments 1a and 1b, the only condition in which this was not the case was the X-Translation condition. Error bars in this (and all following graphs) show the 95% CI of the proportion estimates.

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. 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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