Intent to Experiment: Attribution Reporting API

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John Delaney

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Mar 25, 2022, 5:49:37 PM3/25/22
to blink-dev

Contact emails

john...@chromium.org, apase...@chromium.org, lin...@chromium.org


Developers interested in the Attribution Reporting API can also join the attribution-re...@chromium.org group for updates and announcements.


Explainer

https://github.com/WICG/conversion-measurement-api/blob/main/EVENT.md

https://github.com/WICG/conversion-measurement-api/blob/main/AGGREGATE.md

https://github.com/WICG/conversion-measurement-api/blob/main/AGGREGATION_SERVICE_TEE.md


Specification

https://wicg.github.io/conversion-measurement-api/ (WIP)


Summary

This API measures ad conversions (e.g. purchases) and attributes them to ad interactions without using cross-site persistent identifiers like third-party cookies. 


The API allows measurement through both event-level reports sent directly from the browser, and aggregatable reports which can be processed through a trusted service to create summary reports of attribution data.


An earlier version of this API was in Origin Trial from Chrome 86 through Chrome 97 which only supported click-through event-level reports.


Blink component

A-N/A


TAG review

https://github.com/w3ctag/design-reviews/issues/724


TAG review status

Pending


Risks


Interoperability and Compatibility

               There are several other different attribution measurement proposals from a variety of browser vendors

                 and companies, each offering different forms of privacy and utility:


Safari has proposed and implemented Private Click Measurement.

Mozilla has proposed Interoperable Private Attribution.

Microsoft has proposed MaskedLark.


For general discussion and feedback see: https://github.com/patcg/meetings/tree/main/2022/02/09-telecon


Gecko: No official position, concerns raised in PATCG


WebKit: Negative (https://www.w3.org/2019/09/18-ad-privacy-minutes.html)


Web developers: Engagement in previous origin trial


Ergonomics

N/A


Activation

A successful API flow involves registering multiple events across multiple different navigations/

pages. API reports contain either coarse or encrypted information that can be difficult to compare directly with cookie-based measurement. The current proposal includes a debugging mode to facilitate testing and integration.


WebView Application Risks

N/A



Goals for experimentation

For experimentation with the new iteration of the API, we hope to see that the measurement data made available through the API provides useful ad conversion data for existing use-cases.


Goals specific to this iteration of the API:

  • We hope to see that support for measuring non-clicked ads in the API provides better coverage of existing cookie based attribution measurement solutions, compared to the earlier version of the API.

  • We hope to see that aggregatable reports complement event-level reports and support robust reporting of attributions.

  • We would like to see if the flexibility by the new filtering mechanisms allows more useful reporting compared to the earlier version of the API.


Experiment Configuration

The origin trial for this experiment will be shared among various Privacy Sandbox APIs. Our goal is to allow for co-ordinated experiments to be run by multiple different sites, across multiple APIs in one OT.


This shared origin trial, Privacy Sandbox Ads APIs, will be a third-party origin trial. To ensure that developers can run coordinated experiments without concern for exceeding page load usage thresholds, this Origin Trial will be available for a subset of users by default. Therefore, it will be necessary to feature test to ensure that the API surface you want to use is available after providing your OT token. A second advantage of this configuration is that different experimenters will experiment with the same users, which enables coordination for APIs like FLEDGE across third parties.


Ongoing technical constraints

None.


Debuggability

The proposal includes a debugging mode to facilitate testing and integration, which was a common theme of feedback in the first Origin Trial.


Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)?

Not supported on Android WebView


Is this feature fully tested by web-platform-tests?

No, but will be before shipping


DevTrial instructions

https://developer.chrome.com/docs/privacy-sandbox/attribution-reporting/

 

Requires code in //chrome?

False


Tracking bug

https://bugs.chromium.org/p/chromium/issues/detail?id=1014604


Estimated Milestones

We hope to start the Origin Trial sometime during M101 beta. We plan to continue the Origin Trial until at least M104 to give developers time to test the API and provide feedback. Once we are confident that the APIs are working properly, we will transition the OT from beta to stable channel.


Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/6412002824028160


Links to previous Intent discussions

Intent to prototype: https://groups.google.com/a/chromium.org/g/blink-dev/c/7B0ldtZR_68/m/GjLBu0n4DgAJ

Intent to prototype: https://groups.google.com/a/chromium.org/g/blink-dev/c/2zA5-TuVSkA/m/GVqUUkhfAwAJ

Intent to Experiment: https://groups.google.com/a/chromium.org/d/msg/blink-dev/Ib9-tDFitns/Sm9RXTNaBwAJ

First extension: https://groups.google.com/a/chromium.org/g/blink-dev/c/C0P7ePjITJQ/m/ZYFmn30SDQAJ

Second extension: https://groups.google.com/a/chromium.org/g/blink-dev/c/xCWP1ltlAgw/m/acwN0GIRBQAJ

Third extension: https://groups.google.com/a/chromium.org/g/blink-dev/c/DmsUL3KHqMk/m/J2v3I_aEBAAJ


This intent message was generated by Chrome Platform Status.


Mike Taylor

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Mar 28, 2022, 2:36:50 PM3/28/22
to John Delaney, blink-dev
Hi John,

It would be good to request officials signals from Mozilla and Apple now to give them plenty of time to respond, should this ship in the future. See bit.ly/blink-signals.


Web developers: Engagement in previous origin trial

Was there any feedback from participants?


Ergonomics

N/A


Activation

A successful API flow involves registering multiple events across multiple different navigations/

pages. API reports contain either coarse or encrypted information that can be difficult to compare directly with cookie-based measurement. The current proposal includes a debugging mode to facilitate testing and integration.


WebView Application Risks

N/A



Goals for experimentation

For experimentation with the new iteration of the API, we hope to see that the measurement data made available through the API provides useful ad conversion data for existing use-cases.


Goals specific to this iteration of the API:

  • We hope to see that support for measuring non-clicked ads in the API provides better coverage of existing cookie based attribution measurement solutions, compared to the earlier version of the API.

  • We hope to see that aggregatable reports complement event-level reports and support robust reporting of attributions.

  • We would like to see if the flexibility by the new filtering mechanisms allows more useful reporting compared to the earlier version of the API.


Experiment Configuration

The origin trial for this experiment will be shared among various Privacy Sandbox APIs. Our goal is to allow for co-ordinated experiments to be run by multiple different sites, across multiple APIs in one OT.

Will attribution reporting also be disabled if 3rd Party Cookies are disabled, similar to FLEDGE? (Maybe Topics too?)

This shared origin trial, Privacy Sandbox Ads APIs, will be a third-party origin trial. To ensure that developers can run coordinated experiments without concern for exceeding page load usage thresholds, this Origin Trial will be available for a subset of users by default. Therefore, it will be necessary to feature test to ensure that the API surface you want to use is available after providing your OT token. A second advantage of this configuration is that different experimenters will experiment with the same users, which enables coordination for APIs like FLEDGE across third parties.

(Aside: It would be nice to have some boilerplate feature detection to point devs at for all 3 APIs in this OT)
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Yoav Weiss

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Mar 30, 2022, 5:49:06 AM3/30/22
to blink-dev, Mike Taylor, blink-dev, John Delaney
Thanks for working on this! 

On Monday, March 28, 2022 at 8:36:50 PM UTC+2 Mike Taylor wrote:
Hi John,

On 3/25/22 5:49 PM, John Delaney wrote:

Developers interested in the Attribution Reporting API can also join the attribution-reporting-api-dev@chromium.org group for updates and announcements.

Out of scope for this intent, but I'm excited about potential uses of aggregated reporting for e.g. performance or network error reporting which are currently not being sent for security or privacy reasons. 
So, is the request here to experiment M101-M104 inclusive?
Can you clarify that last bit? Are you planning to start by running the OT on the beta channel only? 
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John Delaney

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Mar 30, 2022, 3:27:23 PM3/30/22
to Yoav Weiss, blink-dev, Mike Taylor
Hi Mike & Yoav,


It would be good to request officials signals from Mozilla and Apple now to give them plenty of time to respond, should this ship in the future. See bit.ly/blink-signals.

Thanks for calling this out, I will follow-up to ensure these are requested and tracked in our chromestatus.


Was there any feedback from participants?

Yes! Here is one example of some detailed feedback we received on the API: https://github.com/WICG/conversion-measurement-api/issues/201

There has been engagement on a number of different issues in our repo (https://github.com/WICG/conversion-measurement-api/issues) and in our bi-weekly meetings (https://github.com/WICG/conversion-measurement-api/tree/main/meetings).

Summarizing a few major points of feedback/gaps while the initial OT was ongoing:
The API is difficult to debug/integrate with due to to the delayed reporting and coarse data
The ability to register non-clicked ads
Supporting more detailed reporting on conversion side information through the aggregate API
How does user-initiated data deletion impact the API? https://developer.chrome.com/docs/privacy-sandbox/attribution-reporting-data-clearing/

As noted in the "Goals for experimentation" section above, we have addressed a number of these with this iteration of the API.


Will attribution reporting also be disabled if 3rd Party Cookies are disabled, similar to FLEDGE? (Maybe Topics too?)

Yes.


(Aside: It would be nice to have some boilerplate feature detection to point devs at for all 3 APIs in this OT)

Agreed, we intend to have detailed developer documentation on this prior to the OT starting.


So, is the request here to experiment M101-M104 inclusive?
Can you clarify that last bit? Are you planning to start by running the OT on the beta channel only?

We're planning to start in M101 beta. We plan to progress to stable in M101 or later, if issues arise, and to continue the origin trial through M104, inclusive.

On Wed, Mar 30, 2022 at 5:49 AM Yoav Weiss <yoav...@chromium.org> wrote:
Thanks for working on this! 

On Monday, March 28, 2022 at 8:36:50 PM UTC+2 Mike Taylor wrote:
Hi John,

On 3/25/22 5:49 PM, John Delaney wrote:

Developers interested in the Attribution Reporting API can also join the attribution-re...@chromium.org group for updates and announcements.

To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+...@chromium.org.

Mike Taylor

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Mar 31, 2022, 8:16:02 AM3/31/22
to John Delaney, Yoav Weiss, blink-dev
Thanks John. LGTM to experiment in M101-104 inclusive.
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