Gather Evidence

Take Stock of Available Evidence

Before we jump in, some terms need to be defined. Evidence refers to the material you use to support the probable truth of your claims. There are two key words in this definition that need further clarification. The first is claim. A claim (or point—we’ll use these terms interchangeably) refers to a debatable statement that you attempt to make other people accept or understand. In business, you will see claims about costs (is something affordable?), feasibility (is something doable?), style (is something appealing?), comparison (is something better than an alternative?), and more.

Debatable can range from mildly questionable to highly contentious. Mildly questionable claims can be disputed, but most people will accept the premise without much evidence (e.g., “New computer software licenses are expensive”). Highly contentious claims tend to be debated more passionately because they often involve politically-charged issues (“Company initiatives to reduce our carbon footprint are a waste of resources”) or issues that are personally meaningful (“Outsourcing public relations is a great way to cut costs”—if any receivers work in the public relations department).

The second key term is probable truth. Because claims are debatable, you won’t be able to prove absolute truth the way you would with a verifiable fact. Instead, you will attempt to support the claim in a way that reasonable people would conclude that your claim is likely true, credible, and believable. Of course, with highly contentious claims, that task will be much more difficult to do. That is why using good evidence to support your claims is so important in business communication. You need as much support as possible to help your receivers accept the probable truth.

With the key terms (evidence, claim, and probable truth) defined, we can move forward in learning how to identify and select evidence to strengthen your messages and achieve your communication goals.

One of the first things you might notice about gathering evidence for business communication purposes is that it is much different from gathering evidence for other purposes. In academic writing, you typically begin by searching online or in a library for articles and books. In business, you typically begin instead by sorting through and making sense of all the evidence around you. Here are some common types of business evidence.

Numerical Data

Because much of business is about generating revenue, containing costs, and maximizing the use of scarce resources, numerical data are going to be essential for many business decisions. Numbers and statistics may come from internal sources, such as sales, costs, profits, losses, and other financial information. They might also include things such as the number of hours spent on tasks, number of employees, and inventory data. Numerical data might also come from external sources, such as government data like the U.S. Census Bureau, industry reports, or academic research studies.

Textual Data

Even though numbers are extremely important, business decisions are not based on numbers alone. Another key source of evidence is textual data. Textual data include any kind of word-based information—whether the words are written or spoken. What differentiates textual data from simple text or words is that it can be qualitatively analyzed to detect patterns. Some common types of textual information in business include comments from customer reviews, open-ended employee responses to organizational climate surveys, and trending hashtags on social media.

Business Publications

Business publications provide valuable information on news and trends in business, which can serve as evidence. General business publications with wide circulations include titles like the Wall Street Journal, Entrepreneur, Forbes, and Harvard Business Review. Additionally, many professional associations publish specialized magazines that help individuals keep up with their field. For instance, human resource managers read HR Magazine, accountants read Accounting Today, and advertising pros read AdAge. Local business publications can be evidence, too. A local business newspaper might sometimes be the best source for information on business trends affecting your community.

Expert Opinions

While you might be tempted to think that an “opinion” doesn’t count as evidence because it isn’t a fact, think again. Opinion-based evidence is critical in business, especially when the source of the opinion is a recognized expert. In most cases, a recognized expert is someone who has collected and analyzed data in their field to make predictions or recommendations. For instance, a trusted financial advisor may predict how a stock will perform after an event, such as a company merger or a new tax code. A cybersecurity consultant may recommend steps to take to prevent your company from experiencing a data breach. An important tech industry leader such as Mark Zuckerberg or Jeff Bezos may speak about how technology will be used in the future.


A testimonial is a statement of endorsement. It may come from an expert or non-expert. But usually, people offering the testimonial should have some sort of personal experience with whatever it is they are endorsing. For instance, you may want to use testimonials from previous clients who had success with your consulting company or your corporate training services. Or you may ask an expert to test your product and provide a testimonial about its quality in comparison to your competitors. Testimonials are powerful because they make evidence personal.


Anecdotes are short stories—sometimes true and sometimes hypothetical—that are used to support claims and illustrate points. They can be particularly helpful when you need to establish an emotional connection or when you need to provide more tangible support for your claim. For example, you might use a story about how the new employee experienced problems during the onboarding process to support your point that there are inefficiencies in your company’s current HR systems. This story may be used by itself or as an example in connection with numerical or textual data that prove your claim about HR inefficiencies.


You’ve probably heard the old adage that a picture is worth a thousand words. So, too, are objects. Objects are anything that can be seen or touched (or even tasted!). Especially when you are communicating with your receiver face to face, an object can be the best evidence. This is why companies roll out new products with presentations where they show pictures, play videos, and give live demonstrations.

Personal Knowledge or Experience

In some instances, you will not have outside information to support your claims and you will instead have to rely on personal knowledge or experience. This kind of evidence might include information you have been given by others, observations you have made, perceptions you hold of various situations, or documentation of what you have done. Personal knowledge is particularly helpful evidence for writing letters of recommendation, completing employee performance reviews, and documenting human resource issues such as sexual harassment or office bullying.

Select Quality Evidence

The point of sharing all these different types of evidence is to let you know that potential evidence is all around you. In contrast to academic research when you may not have enough sources or evidence to build an argument, in business you often will face the opposite problem: You will have so much evidence, you may not know where to start or what to include. Here are some rules to guide you.

Support All Claims

Every key claim or point you make should be supported by some sort of evidence. For example, if one of your key claims is that a particular option is “affordable,” you should provide evidence of its affordable price, perhaps through a cost-comparing chart of similar products. If one of your key claims is that customers have been complaining about a particular product line, then you should provide evidence in the form of an anecdote of those complaints.

For some claims, you may need relatively little support. Other claims will require much more substantive evidence. Generally, the more controversial or complex the claim, the more evidence you will need. For example, recommending a caterer for a holiday luncheon might only require evidence that the caterer can provide a tasty meal within the set budget for the event. Recommending a site for building a new office will require extensive support—from rent and utility costs, to traffic pattern analysis, to customer geo-tracking data, to aesthetics, to parking and more. And it’s likely that you will have to provide the same comparison data across multiple sites to provide evidence you’ve reached a reasonable conclusion.

Use a Mix of Relevant Evidence

While you may have a terrific source of evidence that appears to provide all the support you need, it is still smart to diversify your evidence mix. First, using multiple sources signals to your receiver that you have adequately assessed the available options for potential evidence. Second, if you rely on a single source and the credibility of that source is called into question, you will have other evidence to fall back on. Third, using multiple sources will create a more powerful and trustworthy message, which will increase the likelihood of meeting your goals.

It should go without saying, but your evidence mix should be determined with your receiver in mind. What evidence do you think is going to be the most compelling to your receiver? If you know that your receiver is a numbers person, then you may want to select your mix of evidence to be heavy on numbers. If you know your receiver is particularly swayed by powerful anecdotes, then you may select a few carefully crafted stories to support your numbers.

Use High Quality Evidence

The quality of your overall message is greatly affected by the quality of the evidence you use. If you use excellent evidence, you are well on your way to composing an excellent message and meeting your communication goals. But if you use weak evidence, your entire message may be negatively affected. That’s because if your receiver identifies some of your evidence as weak—even if it’s only one small piece—it may cause your entire argument to be called into question. Therefore, it is of utmost importance to use high-quality evidence. Below are criteria for evaluating evidence quality:

The most essential quality criterion of evidence is that it must be correct. Evidence marred by miscalculations, misrepresentation, or other inaccuracies can misguide decision-making, damage your reputation, and negatively affect business. So take time to “fact check” your evidence. Here are two key questions to guide you.

First, “Does it make intuitive sense?” For instance, assume you do a salary analysis for your full-time employees and see that your lowest-paid employee makes $8,000 per year. An intuition check should tell you there is a mistake somewhere, as a full-time, minimum-wage employee would make much more. If you find evidence that doesn’t pass the intuition check, you should either correct the mistake (if that is within your control) or discard the flawed evidence and search for another source.

Second, “Can it be confirmed?” If evidence is accurate, it should be able to be confirmed. Confirmation can occur in multiple ways. You could rerun analyses and double-check your own calculations. You could verify facts with a knowledgeable colleague. You could seek out other external sources to corroborate the evidence.

There is no arbitrary rule on how new something must be to be considered sufficiently recent. Instead, the principle here is that whatever evidence you use should be recent enough that newer information hasn’t supplanted the information you’re using. For instance, if you want to update your receiver about your social media marketing campaign, data that are more than a week old may be too old to be useful. You’ll need to get more recent data. But if you are estimating costs for purchasing automobiles or advertising space, prices from the last year are probably sufficient. And if you are using evidence from a research study on consumer psychology and how mood affects buying behaviors during the holidays, a study that is 10 or more years old might be perfectly recent. As you look for evidence, track down the most recent sources available.

Another important quality marker for evidence is its representativeness, or how accurately it reflects or represents something else. There are two important facets of representativeness. First, evidence should accurately represent the broader domain being described. Averages and midpoints tend to be more representative than highs and lows. Views held by a majority of people are more representative than views held by a single person.

For example, if customer reviews of your new product line are half positive and half negative, but you only include the positive comments when reporting to your leadership team, that would not be representative. Instead, as a competent business communicator, you would use evidence that represents the broader reality of mixed reviews and, of course, adjust your claims accordingly.

Second, evidence should accurately represent the intent and content of the source. Statistics and quotations are particularly prone to being misrepresented, whether that is by presenting only a portion of what was found or said, mischaracterizing the broader intent, or not providing enough context to make sense of the evidence. Consider the difference here:

Partial Quotation: When asked about recent accusations of sexual harassment in the organization, CEO Paul Seaton said, “It’s not my problem.”

Full Quotation: When asked about recent accusations of sexual harassment in the organization, CEO Paul Seaton said, “It’s not my problem. It’s our problem. We have to work as a company to fix our culture.”

In many ways, all evidence is somewhat biased. Even the act of your choosing what evidence to include and what evidence to exclude introduces bias. Even though you can never be completely bias-free, you should strive to be as unbiased as possible.

In business, an important type of bias is conflict of interest. A conflict of interest occurs when someone’s impartiality may be influenced by a professional or personal interest. For instance, salespeople may not present a fully unbiased account of their company’s services if they will financially benefit from making a sale. Or managers may not be able to write impartial performance reviews for employees who are also friends.

Simply asking, “Who wrote this?” or “Who provided this information?” can help you determine if the evidence is reasonably free from overt bias. For instance, a source such as Wired magazine is going to present less biased product reviews than websites for the companies that make the products.


Your Turn: What Kinds of Evidence Can You Use?

Consider the following examples. What kinds of evidence can you use to support each claim? Try to identify at least two different types of evidence for each one.

1. Your employee has not been performing to company standards

2. Your new product launch was successful

3. Your company should adopt more sustainable, eco-friendly business practices

4. Your recent social media campaign backfired

5. Your company should buy an ad for the Super Bowl

6. Your intern should be hired for a permanent entry-level position

Change Directions if Necessary

At the heart of being evidence-driven is a commitment to letting your evidence drive the argument forward, not your personal agenda. While you may start out with a general direction in mind, stay open to the possibility that the evidence may eventually point you in a different direction. Be willing to change your goals and your message accordingly.

A case in point involves a university task force that explored the possibility of requiring all students to have a laptop computer. The task force started from the position that the college wouldn’t have to invest in more computer lab upgrades if they simply required students to bring their own laptop computer to class. Other universities had done the same and it seemed to be working. So they set off to write a proposal to change policy.

They sought data for some of the key issues affecting their policy proposal, including the cost of computers and software (more than they initially expected), the availability of power outlets in classrooms (far fewer than they realized), and computer software licensing for use on personally owned computers (more complicated than they anticipated). After looking at the evidence, they quickly redirected their efforts with a recommendation to drop the proposed policy change and invest in computer lab upgrades instead.



Icon for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

Business Communication: Five Core Competencies Copyright © 2023 by Kristen Lucas, Jacob D. Rawlins, and Jenna Haugen is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

Share This Book