Selective attention and learning in the classroom
Last registered on December 27, 2018


Trial Information
General Information
Selective attention and learning in the classroom
Initial registration date
November 14, 2018
Last updated
December 27, 2018 8:42 AM EST
Primary Investigator
Other Primary Investigator(s)
PI Affiliation
Additional Trial Information
On going
Start date
End date
Secondary IDs
This trial seeks to establish whether agents selectively pay attention and retain information based on their type. The context is a college-level classroom lecture, party of a compulsory course, plus related mandatory reading material, with specific learning objectives examined through a written essay. The content of the lecture and reading material is on the environmental and health-related impact of the food industry. The hypothesis is that subjects who, before the lecture and exposure to reading material declared to be vegetarian or vegan, will retain more of the information they are presented with. This will be established through a text analysis of the written essays to be compared with a pre-registered list of concepts, which are related to the learning objectives. Effort and truthfulness in revealing the attained learning objectives are incentivised with study credit (grade for the essay) rather than monetary compensation. This trial aims to contribute to the literature on policy design to incentivise costly pro-social behaviour, and in particular on the merits and limits of information interventions.
External Link(s)
Registration Citation
Berlin, Maria and Benjamin Mandl. 2018. "Selective attention and learning in the classroom." AEA RCT Registry. December 27.
Experimental Details
The intervention consists of the exposure to information on the externalities caused by the food industry, in the form of a classroom lecture and a set of mandatory reading material. Vegetarian and vegan subjects, who are hypothesised to be more receptive of this type of information, are randomly matched with other students and assigned to study groups of 4. Each group will then write an essay together.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
The outcome variable will be the share of retained concepts by the individual groups.
Primary Outcomes (explanation)
We defined and registered a list of concepts related to the learning objectives from the lecture and reading materials. Each written essay will be compared to this list. The outcome variable is the share of concepts from the list that are mentioned in the essay.
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
At the baseline, the subjects filled in a short survey in which they report the quantity of meat they have consumed during the previous week, and can identify themselves as vegan or vegetarian if the definition applies. Exam-relevant essays are written by groups of 4 randomly matched students. The outcome variable (share of retained information) will be compared across groups that contain one or more vegan/vegetarian subjects and groups that don't.
Experimental Design Details
Randomization Method
The work groups who jointly author the essay where composed at the beginning of the term. The groups are based on the student's registration number, which is randomly assigned at the moment of enrolment in the program.
Randomization Unit
The randomisation is at the work group level (4 students writing the essay together).
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
92 work groups.
Sample size: planned number of observations
92 essays, one for each work group. The essay is compulsory, however there is the possibility to make up for it, in case the group has valid reason not to turn it in, to make it up by writing an essay question during the final exam in December. Not too many are expected to chose this option because it is disincentivized.
Sample size (or number of clusters) by treatment arms
11 of 92 groups contain a vegetarian or vegan student. So 11 treated units, and 81 control units.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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Analysis Plan

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Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports and Papers
Preliminary Reports
Relevant Papers