All insights

AI explained5 min read

Keep a person in the loop. On purpose.

Design review around consequences, source evidence and the time people need to make a sound decision.

Automation and AI systems help reduce repetitive tasks. But they don’t replace the need for human judgement. That’s why many workflows include a human-in-the-loop (HITL) review step. This means a person checks or approves work where their input matters most.

Designing these human review steps well is vital. Done right, they add oversight without slowing things down or turning into meaningless rubber stamps. Done badly, they create bottlenecks, frustration, or false confidence.

This guide explains how to design human-in-the-loop review steps that balance control with speed. It covers picking where to hand off work, making the review quick and clear, spotting when review stops adding value, and expanding the scope once the process is stable.

#Pick the hand-off carefully

Not every task needs a human check. Reviewing all automated work wastes time and leads to reviewer fatigue. Instead, focus review on:

  • Cases where the automation isn’t confident in its result
  • Situations the system hasn’t encountered before
  • Anything a customer will see or rely on
  • Tasks involving money or legal risk

For invoice extraction, missing fields are one review signal. Duplicate checks, supplier changes, unusual amounts and the consequences of payment also matter. Define approval rules separately from extraction quality, and sample apparently successful cases to detect missed errors.

Use validation rules and evaluated error signals to route work; a model’s confidence score is not a guarantee. A common mistake is setting the hand-off point too early or too late. Too early, and people review too much low-risk routine work. Too late, and risky errors slip through unnoticed.

#Make the evidence easy to review

A review step that’s slow or clunky will not work in practice. If approving one item means opening several tabs, searching emails, or hunting through spreadsheets, it hasn’t removed work: it has moved it.

A well-designed review interface shows three things clearly, in one place:

  • The original information or document
  • The system’s suggested action or extracted data
  • A brief explanation of why this item was flagged or needs review

The reviewer should be able to approve, reject, or flag an item with one or two clicks without leaving the screen.

Worked example: review queue done badly

  • The reviewer must open three separate applications to verify data
  • No clear reason is given for why an item was flagged
  • Items pile up quickly, causing delay and frustration

This leads to long queues, missed deadlines, and reviewers losing faith in the system.

Review queue done well

  • A single interface shows the original document and AI’s extracted data side by side
  • Confidence scores or notes explain why items were flagged
  • One-click options let reviewers approve, send back, or correct data

When the review is this smooth, teams keep up with the queue and exceptions get handled promptly.

#Signs a review step has become a rubber stamp or bottleneck

A human review step should add real value. But sometimes it becomes a formality or a roadblock. Watch out for these signs:

  • Reviewers approve everything without checking carefully
  • Review queues grow longer without clear reason
  • People skip or ignore the review task
  • The same types of issues are repeatedly flagged and ignored

If you notice these, it’s time to rethink the hand-off point, improve the review interface, or retrain the team. A review that is not done properly can create false assurance.

#Widen the boundaries once proven

Start by reviewing a narrow, well-defined set of items. This helps your team learn the process and gain confidence. Once the review step runs smoothly, you can gradually include more cases.

For example, keep all required payment approvals in place while piloting extraction for a small group of suppliers. Expand the supplier set only after measuring errors, review time and missed exceptions.

Expanding too fast leads to large backlogs and frustration. It also hides whether the automation itself needs tuning.

#What goes wrong when human-in-the-loop isn’t designed well

Some common mistakes include:

  • Reviewing everything instead of focusing on exceptions
  • Making the review task too complex or time-consuming
  • Not explaining why an item needs review
  • Not assigning ownership for maintaining the review process
  • Ignoring feedback from reviewers about the queue or system

These errors cause wasted effort, delays, and lower trust in automation.

#The cost of poor human-in-the-loop design

When review steps become bottlenecks or rubber stamps, it can cost:

  • Hours wasted on low-value checking
  • Slow response times to customers or suppliers
  • Increased errors slipping through
  • Frustrated staff and higher turnover
  • Loss of control over important processes

Designing human-in-the-loop review well reduces these risks and keeps your team in control.

#What to do first

Begin by mapping the process you want to automate. Identify where errors or exceptions happen and where human judgement is essential.

Next, decide exactly where to hand off work for review. Use explicit rules and tested signals to make this clear.

Design a review interface that keeps the task quick and simple. Show the original data, the system’s suggestion, and why it needs review in one place.

Start small, with a narrow review queue. Once stable, widen the boundaries gradually.

Remember, the goal isn’t to remove humans from the process. It’s to move their attention to the parts of the work that need it most. A well-built human-in-the-loop step reduces risk, saves time, and keeps your team in charge.

Recognise any of this in your own business? Tell us about it and we’ll say whether it’s worth automating.

Talk through your process