The Effect of Providing Joint Feedback to Students and Educators in Code in Place

Last registered on September 21, 2026

Pre-Trial

Trial Information

General Information

Title
The Effect of Providing Joint Feedback to Students and Educators in Code in Place
RCT ID
AEARCTR-0019599
Initial registration date
September 04, 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
September 21, 2026, 6:52 AM EDT

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

Locations

Region

Primary Investigator

Affiliation
Stanford University

Other Primary Investigator(s)

PI Affiliation
PI Affiliation
PI Affiliation

Additional Trial Information

Status
Completed
Start date
2024-01-01
End date
2024-06-30
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This project builds on previous studies conducted in 2021 on Code in Place, an online programming course where we found that automated feedback to instructors can improve their instruction and student satisfaction. The current study was conducted in the spring of 2024 on Code in Place, and its goal is to understand whether providing feedback to students as well, in addition to providing feedback to instructors, influences the quality of their discourse and student outcomes. Feedback to teachers is known to be an effective way to improve their instruction, but few empirical studies have examined the effect of joint feedback to both teachers and students. To answer this question, the study leverages a randomized controlled trial design and computational natural language processing techniques.
External Link(s)

Registration Citation

Citation
Demszky, Dora et al. 2026. "The Effect of Providing Joint Feedback to Students and Educators in Code in Place." AEA RCT Registry. September 21. https://doi.org/10.1257/rct.19599-1.0
Experimental Details

Interventions

Intervention(s)
The goal of our intervention was to answer the following research questions:

RQ1: Does joint feedback to both students and instructors
improve student outcomes (attendance, engagement in section, assignment completion) above and beyond feedback provided to instructors alone?
RQ1.1.: Does giving students the option to also give feedback back to the instructor further improve these metrics?

RQ2: Does joint feedback to both students and instructors improve instructor outcomes (talk time, talk move rate, NPS, instructor engagement with the course) above and beyond feedback provided to instructors alone?
RQ2.1.: Does giving students the option to also give feedback back to the instructor further improve these metrics?

RQ3: How do treatment effects vary by instructor and student characteristics (demographics=location,age,gender, baseline engagement before feedback, etc.)?

The experimental design is described below.
Intervention (Hidden)
Intervention Start Date
2024-04-27
Intervention End Date
2024-06-04

Primary Outcomes

Primary Outcomes (end points)
● RQ1: treatment effects on student outcomes
○ number of attended sessions between weeks 2-6
○ student talk time in their sessions
○ number of student questions in their sessions
○ proportion of assignment completed for each week (overall proportions listed below)
■ Overall completion proportions in the final data (n = 7,151 students): assignment 0 = 92.5%, assignment 1 = 42.2%, assignment 2 = 62.1%, assignment 3 = 47.1%, assignment 4 = 25.9%, assignment 5 = 21.6%. Assignment 0 is used as a baseline covariate rather than an outcome, since it precedes any feedback.

○ exploratory
■ survey responses (NPS, quality of instruction)
● the response rate is only 12.6% (886 of 7,055 arm-assigned students), so we may not be able to rely on this data that much
■ engagement with in-platform things, e.g. IDE
● RQ2: treatment effects on instructor outcomes
○ engagement with feedback
■ viewing their feedback before their subsequent section (binary)
● At any point during the course
● By week
■ time spent on feedback (in seconds)
○ impact on section practices
■ talk time
■ talk move rate for each of the 3 talk moves
■ proportion of students engaged
○ exploratory
■ self-reported outcomes (e.g. NPS)
● the response rate is 24.5% (150 of 611 instructors), which may limit the conclusions we can draw from this data
■ engagement with in-platform things, like IDE or teachers lounge
● RQ3: heterogeneity analyses
○ same outcomes as above, using the following variables for heterogeneity:
■ gender (binary)
■ returning instructor (binary)
■ age
■ US location (binary)
■ baseline practices and engagement (1st week)
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We randomized participants at the student level, implemented as a cluster randomization over pre-course section rosters. Concretely, the list of 606 pre-course section rosters was shuffled and split into three equal parts, and every student on a given roster was assigned to that roster's condition. Treatment then travelled with the student for the rest of the course: a student's condition never changed, including in the weeks when they attended a section other than their own.

Two consequences follow for the analysis. First, the unit of randomization is the pre-course section roster, so confirmatory standard errors are clustered at that level rather than at the level of the section a student happened to attend. Second, because rosters were revised between randomization and the first section, and because students moved between sections during the course, sections are not pure with respect to condition (see Prior knowledge below).

Before the course began: We randomized students once they were accepted to the course, before the first section. Third of the students (n=2188 name=StudentFeedback group) were assigned to receive automated feedback in addition to their instructors receiving feedback. Another third of the students (n=2187, name=StudentSLFeedback group) both received feedback, similar to the StudentFeedback group, and also had the option to share feedback back to their instructor. Control group students did not receive feedback.

Control-group students were not given personalized feedback. They saw a static acknowledgement message (“thank you for showing up”) in the same place in the roadmap where treated students saw their personalized feedback, so the contrast between arms is the content of the feedback rather than the presence of a roadmap item.

Once the course began: On the Monday following each section, students were able to access the automated feedback within their roadmap (checklist before their next section).

The feedback for the StudentFeedback group looked had the following components:
● Introduction to the feedback
● Number of student questions asked
● List of student questions asked with timestamps
● Reminder about the importance of asking questions
● Link to class and section forum to ask further questions
● Student talktime percentage + percentile
● Opportunity to write a reflection
Experimental Design Details
Randomization Method
Coin flip
Randomization Unit
Section assignment
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
Sample size: 564 instructors and 6759 students at the time of randomization
Sample size: planned number of observations
Sample size: 564 instructors and 6759 students at the time of randomization
Sample size (or number of clusters) by treatment arms
In the final data pull, the platform records 7,174 students and 611 instructors across 612 sections; 7,055 students (98.4%) carry an experimental arm assignment (Control n = 2,363; StudentFeedback n = 2,311; StudentSLFeedback n = 2,380). The randomization file itself assigns 7,604 students across 606 pre-course section rosters (Control n = 2,539; StudentFeedback n = 2,498; StudentSLFeedback n = 2,567). The three counts differ because enrollment and section rosters continued to change between randomization and the first section, and because some enrolled students never appear in the course logs. Confirmatory analyses are restricted to students who carry an arm assignment in the final data; we will report the reconciliation between the randomization file and the final data pull, and confirm that attrition between the two is not differential by arm.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Stanford IRB
IRB Approval Date
Details not available
IRB Approval Number
68376
Analysis Plan

Analysis Plan Documents

Preregistration details and analysis plan

MD5: 737fb574dccd5c7ec16612c51ecbd7a1

SHA1: 6d4059c151eaff1f9f2234ed7ed761b7c5d12104

Uploaded At: September 04, 2026

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