Social Learning in Groups: an Experimental Study
Last registered on September 12, 2018


Trial Information
General Information
Social Learning in Groups: an Experimental Study
Initial registration date
September 11, 2018
Last updated
September 12, 2018 1:15 AM EDT

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Primary Investigator
Other Primary Investigator(s)
PI Affiliation
UC Berkeley
PI Affiliation
Additional Trial Information
In development
Start date
End date
Secondary IDs
In this project, we use controlled laboratory experiments to investigate the aggregation of information in groups and the efficiency properties of this process. In particular, we construct a natural setting in which we will study how the size of the group, the strength of the signals, and information structure affect the degree to which information contained in the private signals is aggregated through mutual observation of others' actions.
External Link(s)
Registration Citation
Agranov, Marina, Philipp Strack and Omer Tamuz. 2018. "Social Learning in Groups: an Experimental Study." AEA RCT Registry. September 12.
Experimental Details
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
We are interested in characteristics of the learning process and efficiency of information aggregation in different treatments. Specifically, we will investigate how fast (if at all) groups learn the true state of the world, whether or not group members converge to the same action when they observe each other's actions, whether the disagreement happens and whether its likelihood depends on the size of the group. We are also interested in documenting the groupthink phenomenon and understanding the mechanisms for its initiation and its dynamics. Moreover, we will investigate the effect of the information structures on the ability of subjects to learn the true state and impediments along this path.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
In the experiment, the groups of different size will play the finite-horizon game based on the environment studied in Harel, Mossel, Strack and Tamuz (2018) paper "Groupthink and the failure of information aggregation in large groups". The treatments will differ in the number of participants in a group, the precision of participants' private signals as well as in the information available to the participants throughout the game. In addition, at the end of the experiment, we will conduct several control tasks that elicit participants' risk preferences, overconfidence and IQ measures. The additional treatments will include variants of the same game which aim to investigate the mechanism that drives outcomes observed in the baseline game.
Experimental Design Details
Not available
Randomization Method
Randomization is done in office by a computer
Randomization Unit
Experimental sessions
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Between 200 and 400 participants
Sample size: planned number of observations
Between 200 and 400 participants
Sample size (or number of clusters) by treatment arms
Between 20 and 100 subjects per treatment (depending on the group size)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
Committee for the Protection of Human Subjects (IRB) at Caltech
IRB Approval Date
IRB Approval Number