United States: Misleading Advertising: The Truncated Graph

Graphs may seem like a safe, simple way to visually convey information to consumers, but they present a minefield of potential hazards for the unwary advertiser. In this post, we will explore one minor tweak that can transform a graph from accurate to misleading: the truncated graph.

First, it is crucial to understand that advertisers are responsible for all reasonable interpretations of their ads. Obviously, this includes intentionally-conveyed messages. However, it also extends to those messages that were unintentionally conveyed. Advertisers must therefore be wary of making claims that can be reasonably interpreted in a variety of different ways, or could easily be misinterpreted, because they may be called upon to provide supporting evidence for claims they did not intend to make, and cannot support.

Graphs are one particularly easy way to fall into the trap of unintentional messaging. Whether they be line, bar, scatterplot or otherwise, graphs make frequent appearances in ads. And for good reason – they can be an effective way to visually depict product data, particularly as a means of distinguishing between competing products. But without proper precision, they can easily lead audiences astray.

Most graphs have two axes – an X-axis (the horizontal line at the bottom) and a Y-axis (the vertical line, typically on the left-hand side). These axes usually bear labels showing what is being measured (e.g. product efficacy on the Y axis and time on the X axis would show "efficacy as a function of time" or, more simply, how well a product performed at certain times).

Let's say you have two sets of data showing efficacy over time for products A and B. Your efficacy is measured in percentages, with a scale from 0 to 100, and your time points are measured in days at one-day increments from 0 to 5. Your data sets look like this:

There are myriad ways you could represent these data. The most straightforward is a simple line graph with your Y-axis going from 0 to 100 and your X going from 0 to 5, like so:

This graph clearly shows that Product A performs better than Product B, albeit not by a huge amount. So what do you do with these data? The graph won't blow anyone out of the water – it's not as if Product A outperforms B by 30, 40 or 50 percent. And the space between the product lines is simply not big enough to catch anyone's eye.

When faced with this kind of problem, some advertisers will use what's known as a truncated graph, where part of the Y-axis is removed. Here are the same data used in the above graph, but plotted with a truncated Y-axis:

If you look carefully at the Y-axis, you'll find that it is incomplete, or "truncated" – the bottom half is missing, in this case. This has the effect of drastically increasing the space between the two product data lines. Here, because half of the Y-axis was removed (and therefore half the graph), the space between the lines showing efficacy for products A and B is doubled. This has the visual effect of vastly overstating – indeed, doubling – the difference between the products. While a thorough inspection of the image would reveal the manipulation, it would not be unreasonable for a consumer to glance at this chart, see a large gap between A and B, and conclude that A is far superior – an unsupported conclusion.

This kind of graph manipulation has been consistently rebuffed by the National Advertising Division – a branch of the Better Business Bureau responsible for resolving disputes about national advertising, typically between an advertiser and a competitor.

In the NAD decision Zoetis Inc. (Simparica), Report # 6013, NAD Case Reports (October 2016), which concerned canine anti-parasite products, NAD recommended discontinuation of an ad featuring a truncated line graph much like the above example:

NAD was also concerned about the manner in which the graphs were depicted in Zoetis' advertising. The Y-axis in the graph is shorter from 0-70 than it is between 70 and 100. This truncated Y-axis does not reflect the actual efficacy scale from 0-100 and could reasonably convey a message overstating the performance differences between the products. For the foregoing reasons, NAD recommended that Simparica discontinue its chart demonstrating the comparative efficacy of Trifexis and Simparica... (emphasis added)

Similarly, in Colgate-Palmolive Company (Colgate Sensitive Pro-Relief Toothpaste), Report # 5443, NAD Case Reports (March 2012), an NAD decision about toothpaste advertising, NAD stated:

NAD was further troubled that the graphs shown in the advertisement are truncated. The "tactile sensitivity" graph only extends from 0 to 30 grams of force, rather than the full 50-gram scale. Likewise, the "air blast sensitivity" graph only shows sensitivity scores ranging from 0.0 to 1.0, rather than the full scale which extends to a 3.0 score. By omitting the top end (31-50 grams) of the Yeaple scale, and the top end of the Schiff scale (1.1-3.0), these graphs exaggerate the difference between the products at two weeks. NAD therefore recommended that Colgate either discontinue the graphs that are shown in the professional advertisement, or modify them such that the scales do not visually exaggerate the differences between the products. (emphasis added)

And in Unilever United States, Inc. (Degree MotionSense and Degree Clinical Protection Antiperspirants), Report # 5819, NAD Case Reports (March 2015), in a dispute over antiperspirant advertising, NAD again found:

NAD was also concerned about the manner in which the graphs were depicted in both commercials. The graphs are truncated and do not reflect the actual scales used in the studies. In the Degree Men commercials, the scale is from 0 to 70 percent, not 0 to 100. Similarly, in the Degree Women's commercials, the scale is from 0 to 3, not 0 to 10. The truncated graphs dramatically overstate the performance differences between the two variants. (emphasis added)

While graphs are clearly an effective means of persuasion, advertisers must be wary of how they're deployed. Truncating your graph may seem like an easy way to spruce up your ad, but if the message conveyed doesn't conform to the underlying data your ad will be susceptible to a challenge at NAD.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

In association with
Related Topics
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Mondaq Free Registration
Gain access to Mondaq global archive of over 375,000 articles covering 200 countries with a personalised News Alert and automatic login on this device.
Mondaq News Alert (some suggested topics and region)
Select Topics
Registration (please scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions

Mondaq.com (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of www.mondaq.com

To Use Mondaq.com you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions