Initial trials
In 2021, with the support of the Bank of England and Kantar Public, we conducted a series of randomised controlled trials to test just how effective the Plain Numbers Method could be.
We tested communications from five companies:
We recruited 5,000 participants representative of the UK population and compared an existing communication with a Plain Numbers version.
The Plain Numbers version sought to communicate the same information in a way that was clearer and easier to understand.
For each communication we asked participants actual comprehension questions, to test whether they had understood what was being communicated.
The measure of customer understanding was how many people correctly answered at least 4 out of 5 questions.
View a summary of the results below and read the full research report here.
Thames Water
customer bill
Original version, answering
at least 4 questions correctly
Plain numbers version
The Plain Numbers Method in action
Numbers themselves
Combined the quarterly charges, removed the 4 decimal places and moved the calculations to the sidebar along with a link to read finer detail.
Numbers in context
Talking ‘human to human’ and making the numbers relatable by providing context and comparators.
How we think
No decisions are needed but seeking active engagement so introduced clearer headings to support ‘fast’ / System 1 thinking.
Full research results for Thames Water here.
The Plain Numbers version of the customer bill
Click on the image to view the detail.
Clearscore balance
transfer offer
Original version, answering
at least 4 questions correctly
Plain numbers version
The Plain Numbers Method in action
Numbers themselves
Doing the maths by converting a percentage fee to the specific cash amount and providing the total saving.
Numbers in context
Replaced the context-specific term ‘Balance transfer offer duration’ with the month the offer ends.
How we think
Enabled customers to make an informed choice by ensuring the key information for each card was presented in the same way.
Full research results for Clearscore here.
Left: The original version of the offer
Right: The Plain Numbers version of the payment options
Click on the image to view the detail.
Octopus Energy monthly energy email update
Original version, answering
at least 4 questions correctly
Plain numbers version
The Plain Numbers Method in action
Numbers themselves
Rounded to the nearest pound thereby removing 14 numerals from the page.
Numbers in context
Created a simple narrative with the headlines up top and then the detail below. Converted ‘Your balance was x’ to ‘there was x in your account with us’.
How we think
No decision required but simple explanation of seasonality effect to put customer at ease.
The Plain Numbers version of the account summary A
Click on the image to view the detail.
Numbers themselves
Pictorial representation to tell the story of what is happening in the month - easier for some to interpret than abstract numerals.
Numbers in context
Waterfall diagram chosen to replace original receipt format to provide a more dynamic representation of activity in the month
How we think
No decision required so image used to enable quick / System 1 interpretation of monthly activity.
Full research results for Octopus Energy here.
The Plain Numbers version of the account summary B
Click on the image to view the detail.
Direct Line choosing
your excess document
Original version, answering
at least 4 questions correctly
Plain numbers version
The Plain Numbers Method in action
Numbers themselves
Relegated numbers that were not relevant to the main voluntary excess decision further down the page.
Numbers in context
Simplified the words around the numbers and removed (or explained) all technical language.
How we think
The customer needs to make an important decision here so providing the customer with a brief summary of the choice to best enable them to make an informed decision
Full research results for Direct Line here.
The Plain Numbers version of the excess information
Click on the image to view the detail.
Atlanta Insurance
payment options
Original version, answering
at least 4 questions correctly
Plain numbers version
The Plain Numbers Method in action
Numbers themselves
Relegated’ the FCA-mandated information, which is off-putting and few understand, further down the page.
Numbers in context
Human to Human language, removed technical terms including Vehicle Insurance Premium, New Business Arrangement Fee, commission, Insurance Premium Tax, deposit, credit broker, third party lender, premium finance, annual premium, Deposit Payable, Total Amount Payable, Total Amount of Credit, Representative APR and Interest Rate.
How we think
Enabled customers to make an informed decision about the use of credit by providing like-for-like totals that are close to each other on the page.
View the full research results for Atlanta here.
The Plain Numbers version of the payment options
Click on the image to view the detail.
View more research and case studies
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ClearScore APR
In 2024 we partnered with Clearscore to explore whether clearer, more intuitive credit information could improve consumer comprehension. We were interested in whether including APR and a representative example helps decision-making.
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Plain Numbers in Practice report
In July 2024 we published our Plain Numbers in Practice report, highlighting the diverse applications of the Plain Numbers Approach across a wide range of communications.
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Case studies
See how Plain Numbers improves customer understanding with real-world case studies.
Numbers shape what people understand, how they make decisions, and who they trust.
Get them right, and you can unlock a whole new level of clarity, confidence, and connection with your customers. We can show you how.