Govern
Decision Timeline
What happened and when?
Lays out a decision as a chronology of steps and actors, from data collection through review to outcome.
- Evidence: research-based (Kroll et al. 2017, Diakopoulos 2016)
- Tested: concept only, mock data
Overview
Why it matters
A decision is not a moment. It's a sequence.
A credit decision involves data collection, scoring, review, possibly an override, documentation and a letter. Each step happens at a specific time, by a specific actor, human or AI. The person receiving the decision sees none of it.
This pattern shows how a decision was reached, in order. Auditors use it to reconstruct cases. The people affected use it to understand what happened to them. Audit Trail & Logging is the record underneath.
What does it look like?
Applicant reviewing what happened
Applicant reviewing what happened
- Applicant receives a declined decision and wants to understand the process.
- They open "What happened with my application?"
- Timeline shows: application submitted (by applicant) → automated assessment completed (system) → additional documents requested (caseworker) → documents received (applicant) → case reviewed (caseworker) → decision issued (caseworker).
- Applicant can see that a human was involved and when. They may choose to request review if they have new information.
Auditor investigating a complaint
Auditor investigating a complaint
- Regulator requests the full decision record for a specific case.
- Auditor accesses the audit timeline view.
- Full timeline shows all events with timestamps, system version references, data snapshots, and caseworker notes.
- Auditor identifies that the caseworker override was not documented with a reason: a process compliance issue.
- Auditor files a finding.
Caseworker reviewing a complex case
Caseworker reviewing a complex case
- Caseworker picks up a case that has been in process for 2 weeks.
- Timeline shows: the initial assessment, two document requests, one response from the applicant, a partial update, and a pending review step.
- Caseworker understands the full history without reading through case notes: the timeline provides the context needed to pick up where the previous reviewer left off.
When does it fit?
Use it when
- Decisions involve several steps and both AI and people
- People have a right to know what happened
- Appeals or audits need a reviewable history
Skip it when
- The decision is a single automated step
- The timeline would reveal confidential internal details
Design
How do I apply it?
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Name the actor for every step.
"Assessment completed" without saying by whom can't be audited.
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Use plain language.
"Automated assessment completed", not an API response.
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Make AI and human steps look different.
That line is often the most important one in the whole process.
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Include the person's own actions.
Documents submitted and reviews requested are events too.
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Give affected people a simpler version.
The full timeline is for auditors. People need "what happened, in order".
How can I show it?
Current status indicator
Where the case stands right now.
A clear "where we are now" marker showing the current state of the case: useful when a decision is still in process (pending review, awaiting documents).
Vertical event timeline
Every event with date, type and actor.
A chronological list of events presented as a vertical timeline with: - Date and time - Event type (data received, model scored, caseworker reviewed, decision issued, etc.) - Actor (automated system, caseworker name or role, applicant) - Brief description of what happened
Event type icons
Automated, human, document, flag, decision at a glance.
Visual differentiation between event types: - 🤖 Automated step - 👤 Human action - 📄 Document event (submitted, received, requested) - ⚠️ Flag or alert - ✓ Decision or resolution
Decision point highlight
The moment the decision was made, and by whom.
Visual emphasis on the specific moment a final decision was made and by whom: distinguishing the decision event from the surrounding process events.
Expandable event detail
Open any step to see what was known then.
Each timeline entry can be expanded to show more detail: what data was available at that point, what the model score was, what the caseworker noted. Primary view stays compact; detail is accessible.
Timeline export
A downloadable record for audits.
For audit purposes: a downloadable record of the full decision timeline, including timestamps and actor references. Used by auditors and compliance teams.
What does it cost?
Completeness vs. comprehensibility
A full audit timeline has dozens of events. Design one view per audience.
Transparency vs. confidentiality
Reviewer notes and internal rules may not belong in the public view. Draw that line on purpose.
Looking back vs. right now
Timelines serve review. People in progress need "where is my case now?".
Connections
Which patterns work with it?
Audit Trail & Logging
What is the complete record of this decision?
Audit trail is the data collection layer. Decision timeline is the presentation layer: the human-readable view of the audit trail data.
Contestability & Appeal
How can I challenge this decision?
The decision timeline is essential context for a contestability workflow. Users challenging a decision need to know the process that produced it.
Human-in-the-Loop
Who can review or override this decision?
Overrides are key events in the timeline. The timeline makes HITL visible: when a human intervened, who it was, and what they decided.
Role-Based Explanations
Is this explanation appropriate for me?
The appropriate view of the timeline differs by role. Affected persons see a simplified view; auditors see the full technical record.
Sources (3)
Sources (3)
Kroll et al. (2017) — Accountable Algorithms
argues that algorithmic accountability requires process transparency: the ability to trace how a decision was reached, not just what the decision was. The decision timeline is the design implementation of this accountability requirement
Diakopoulos (2016) — Accountability in Algorithmic Decision Making
examines algorithmic accountability from a computational journalism perspective, distinguishing transparency about a system's existence, inputs, logic, and outcomes. Supports traceable, reconstructable decision processes as a precondition for accountability. Published in Communications of the ACM, 59(2)
European Union (2024) — EU AI Act, Article 12
requires record-keeping for high-risk AI systems, including logging of decisions, to enable post-hoc audit
A decision is challenged, and nobody can say what happened when.
Who reviewed it, in what order, with what information. That's where this pattern starts. Let's look at your interface together.
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