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To what extent does the choice to acquire information determine learning?

Last registered on April 02, 2024


Trial Information

General Information

To what extent does the choice to acquire information determine learning?
Initial registration date
December 19, 2023

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
December 21, 2023, 8:02 AM EST

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
April 02, 2024, 1:10 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.


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Primary Investigator

London School of Economics and Political Science

Other Primary Investigator(s)

PI Affiliation
London School of Economics and Political Science

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
This study explores the impact of (no) choice in information acquisition on learning outcomes in the context of health communication. Decisions about investments into health are often made under uncertainty by individuals who lack perfect information. Information provision interventions are used to counteract this by supplying accurate information. However, these interventions often fail to improve participants’ knowledge or shift their decisions towards the optimum. This study investigates one potential reason for this: the fact that the way that information is acquired affects the extent of learning. I study whether giving individuals a choice in accessing information about the new malaria vaccine affects their attention to the information and their resulting knowledge about, and support for, the vaccine. I do this in a survey experiment conducted in Ghana where I randomly assign participants to 1) passively watch a placebo video about child development; 2) passively watch the treatment video about the malaria vaccine; 3) the choice group, where participants express a preference between the placebo and treatment videos. In group 3, there is a further randomisation of participants following the choice; some watch the video they preferred, while others watch the video they did not prefer. I compare how individuals respond to the treatment video if they watch it passively, watch it "keenly" (after choosing it), or watch it "forcedly" (after choosing against it). Through this study, I seek to inform health communication strategies, particularly in the context of emerging health interventions.
External Link(s)

Registration Citation

Grabowska, Marta and Mylene Lagarde. 2024. "To what extent does the choice to acquire information determine learning?." AEA RCT Registry. April 02.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
1. Attention to information measured through a summary index of video recall.
2. Malaria and malaria vaccine knowledge measured through a summary index of a battery of 5 questions.
3. Support for malaria vaccine, measured through a summary index of vaccine endorsement, demand for further information about the vaccine, and intention to vaccinate child if eligible in the future.
Primary Outcomes (explanation)
1. For the measure of the level of attention paid to the info video, we ask the respondent to recall five details regarding the video they just watched. The focus of the questions is on the production and story side of the video, such as the characters (e.g., ``what was the colour of the baby's dress?'') and the background (e.g., ``was it raining when...''), rather than the information content.
2. We will summarise the participants' knowledge across five domains covered by the info video. The questions vary in difficulty in order to provide a meaningful measure of knowledge and differential learning between respondents.
3. As the vaccine is not yet available everywhere in Ghana, we are unable to offer the vaccine to the participants’ children. Therefore, we capture a range of measures which reveal interest and support for the vaccine. We capture the following revealed measures of support: endorsement (two methods - lieklihood of recommending to others, and being willing to share the malaria information with own contacts); demand for further information (two methods - willingness to receive updates about the vaccine over SMS, sometimes at a fee; and the duration of asking and number of questions asked when offered the chance to inquire further about the malaria vaccine); and intention to vaccinate own child if eligible, elicited using a list experiment.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Participants who consent to take part in the study will be randomly assigned to one of 3 intervention arms:

1. Placebo arm: participants passively (i.e., with no choice of video offered) watch a placebo information video about an unrelated topic on child care. The video is very similar in design to the malaria video but delivers none of the information. This arm consists of 500 participants.
2. Passive treatment: participants passively watch the intervention video. This arm consists of 500 participants.
3. Offered a choice: participants are asked for their preference between the placebo and the intervention videos. They learn that their choice is more likely to be shown, though it is still randomised by the survey device. There are 1,400 participants in this arm.

A second randomisation then takes place, assigning participants to either their choice video or not. This creates four further intervention arms:
3.1 Those who wanted to view the intervention video and are shown it ("keen" viewers)
3.2 Those who wanted to view the placebo video but are shown the intervention video ("forced" viewers)
3.3 Those who wanted to view the placebo video and are shown it
3.4 Those who wanted to view the intervention video but are shown the placebo video

The final sizes of arms 3.1-3.4 will be determined in part by the participant's choices; we will allocate 90% of those who preferred to view the malaria video to indeed view the malaria video (3.1) and 80% of those who preferred to view the placebo video to instead view the malaria video (3.2).
Experimental Design Details
Not available
Randomization Method
Randomisation done within each survey device according to pre-specified randomisation proportions. We use SurveyCTO.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
2,400 individuals
Sample size (or number of clusters) by treatment arms
1. Placebo arm: 500.
2. Passive treatment: 500.
3. Offered a choice: 1,400.
3.1: 1,400 * % prefer malaria video * 0.9
3.2: 1,400 * % prefer placebo video * 0.8
3.3: 1,400 * % prefer placebo video * 0.2
3.4: 1,400 * % prefer malaria video * 0.1
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Ghana Health Service Ethics Review Committee
IRB Approval Date
IRB Approval Number
GHS-ERC: 014/03/23
IRB Name
LSE Research Ethics Committee
IRB Approval Date
IRB Approval Number