Detecting AI-Generated Text in Online Survey Responses

Last registered on January 12, 2026

Pre-Trial

Trial Information

General Information

Title
Detecting AI-Generated Text in Online Survey Responses
RCT ID
AEARCTR-0017629
Initial registration date
January 09, 2026

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
January 12, 2026, 8:08 AM EST

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

Locations

Region

Primary Investigator

Affiliation
University of Michigan, Ann Arbor

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2026-01-09
End date
2026-01-12
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study examines whether a syntax-based detection method based on character encoding patterns can identify AI-assisted text generation in open-ended survey responses. Specifically, it evaluates whether mixed or ASCII-only quotation mark usage, which arise from copy-pasting text generated in AI user interfaces such as ChatGPT, occurs in incentivized online survey responses and whether such patterns align with or diverge from respondents’ self-reported AI use.

Registration Citation

Citation
Buschmann, Andy. 2026. "Detecting AI-Generated Text in Online Survey Responses." AEA RCT Registry. January 12. https://doi.org/10.1257/rct.17629-1.0
Experimental Details

Interventions

Intervention(s)
Participants are randomly assigned to one of three survey conditions that vary how artificial intelligence (AI) tools are described prior to a creative writing task. In one condition, participants are explicitly told they may use AI tools to assist with the task. In a second condition, participants are explicitly instructed not to use AI tools. In a control condition, AI tools are not mentioned prior to the task.
Intervention (Hidden)
The survey includes a creative writing task in which participants write an ending to a short story. Prior to this task, participants are randomly assigned to one of three instructional framings: (1) AI Allowed (explicit permission to use tools such as ChatGPT), (2) No-AI Instruction (explicit instruction not to use AI tools), or (3) Control (no mention of AI). After completing the task, participants report how they completed it (with or without AI assistance). Open-ended responses are later analyzed using a syntax-based detection method that identifies character encoding patterns associated with copy-pasted AI-generated text.
Intervention Start Date
2026-01-09
Intervention End Date
2026-01-12

Primary Outcomes

Primary Outcomes (end points)
Presence of character encoding patterns in open-ended survey responses consistent with AI-assisted text generation.
Primary Outcomes (explanation)
The primary outcome is a binary indicator derived from participants' written responses. Responses are flagged if they contain character encoding patterns consistent with copy-pasted AI-generated text, including the presence of both straight (ASCII) and typographic (Unicode) quotation marks within the same response, or the exclusive presence of straight quotation marks. These indicators are constructed using transparent pattern-matching rules applied to the raw text.

Secondary Outcomes

Secondary Outcomes (end points)
Self-reported AI use during the writing task; response length (word and character counts); agreement between detection flags and self-reported AI use.
Secondary Outcomes (explanation)
Self-reported AI use is measured using a post-task multiple-choice question asking how participants completed the writing task. Response length is calculated from the open-ended text. Agreement outcomes are constructed by cross-tabulating detection flags with self-reported AI use categories.

Experimental Design

Experimental Design
The study uses a between-subjects/split-ballot randomized survey experiment. Participants complete a creative writing task and related survey questions. The experimental manipulation consists of varying the instructional framing regarding AI tool use prior to the writing task. Outcomes are measured using both self-reports and post hoc analysis of written responses.
Experimental Design Details
Participants are randomly assigned at the individual level to one of three instructional conditions regarding AI use before completing a creative writing task. The main analysis compares the prevalence of encoding-based AI-detection flags across conditions and examines agreement between detection results and self-reported AI use. Additional robustness checks examine sensitivity to response length and alternative detection thresholds. No responses are excluded based solely on detection flags.
Randomization Method
Randomization is implemented by the survey platform (Qualtrics) using a built-in computer-generated simple random assignment procedure.
Randomization Unit
Individual survey respondents.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
Not applicable (individual-level randomization).
Sample size: planned number of observations
Approximately 450 individual respondents.
Sample size (or number of clusters) by treatment arms
Approximately 150 respondents in each of three conditions: Control, AI Allowed, and No-AI Instruction.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
This study is primarily descriptive and methodological rather than designed to detect a specific causal effect size. The planned sample size allows for estimation of detection rates with acceptable precision and for comparison of detection prevalence across experimental conditions using confidence intervals rather than formal hypothesis testing. Minimum detectable effect sizes were therefore not the primary basis for sample size determination. That said, with 150 respondents per condition, the study can detect differences in detection rates of approximately 6-8 percentage points between conditions with 80% power at alpha = 0.05, depending on baseline prevalence.
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
University of Michigan, Ann Arbor
IRB Approval Date
2026-01-07
IRB Approval Number
HUM00286625

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials