To ask or to observe: the impact of baseline measurement on future sanitation behavior

Last registered on May 30, 2024


Trial Information

General Information

To ask or to observe: the impact of baseline measurement on future sanitation behavior
Initial registration date
May 24, 2024

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
May 30, 2024, 3:40 AM EDT

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



Primary Investigator

University of Groningen

Other Primary Investigator(s)

PI Affiliation
University of Groningen
PI Affiliation
University of Groningen

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Baseline data collection is a common practice among empirical researchers. While asking questions is often cheaper, observational data is typically trusted more. In this study we develop an experiment in Bangladesh where we randomly assign respondents to (i) only self-reported questions on sanitation behavior, (ii) a combination of observation and self-reported questions on sanitation behavior, or (iii) no questions on sanitation behavior. Our first objective is to determine if observational data influences self-reported responses at baseline. Subsequently, we will examine whether self-reported questions and observational data impact both self-reported and observed sanitation measures at the endline. Additionally, we will investigate whether self-reported questions and observation affect the impact of a separate sanitation intervention.
External Link(s)

Registration Citation

Langley, Madeline, Kritika Saxena and Mark Treurniet. 2024. "To ask or to observe: the impact of baseline measurement on future sanitation behavior." AEA RCT Registry. May 30.
Experimental Details


In the self-report arm, we will ask sanitation questions related to waste disposal (from latrine, diapers and garbage) and handwashing. In the observation arm, before we ask the same sanitation questions, we will first ask whether we can observe, respectively, the respondents’ waste disposal facilities and handwash area.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Waste disposal observation, Waste disposal self-report, Handwashing facility observation, Handwashing facility self-report and Handwashing behavior self-report
Primary Outcomes (explanation)
See pre-analysis plan

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)
See pre-analyis plan

Experimental Design

Experimental Design
We have 3 baseline survey arms:
● Group 1: [R] only reported questions
● Group 2: [R+O] both reported and observation questions
● Group 3: [C] Pure control group that gets not questions on sanitation and health in the baseline
Experimental Design Details
Not available
Randomization Method
Randomization done in office by a computer
Randomization Unit
Individual randomization, stratified by the group-level treatment assignment of the larger RCT within which this survey experiment takes place
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
1034 individuals
Sample size: planned number of observations
1034 individuals
Sample size (or number of clusters) by treatment arms
343 individuals in group 1, 344 in group 2, 347 in group 3
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
We will test our hypothesis at the 5% significance level. Assuming a sample size of 1034 individuals at baseline, an equal split over our three survey arms and no attrition, we have 80% power to detect an effect of 0.214 standard deviations across two survey arms. With 20% attrition, the minimum detectable effect increases to 0.239 standard deviations.

Institutional Review Boards (IRBs)

IRB Name
Institutional Review Board, BRAC James P Grant School of Public Health, BRAC University
IRB Approval Date
IRB Approval Number
Analysis Plan

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