When your CEO, CFO, and other C-Suite executives gather in the board room and talk about ROI, they’re talking about the accounting term. Return on Investment, when raised in the board room, is the amount, expressed as a percentage, that is earned on a company’s total capital, calculated by dividing the total capital into earnings before interest, taxes, or dividends are paid. ROI is synonymous with ROR—Rate of Return. A series of precise mathematical formulae are used to calculate ROI.

Of course, it’s common to talk about return on investment more casually. You invest time, money, and resources in an effort and want to know what you got out of it. It’s easy to refer to the results of your effort as ROI. And I understand that, outside of the C-Suite, ROI has assumed a variety of different meanings, all of which come down to the perceived value of an expense or investment.

I’m a huge believer in measurement as a foundation for any kind of communication effort, whether it’s PR, marketing, whatever. Budget-conscious executives are increasingly less likely to fund communications if they can’t see how the effort is helping the business achieve its goals, so it’s vital to be able to demonstrate the results our efforts have produced. It’s also critical so we can figure out what adjustments we need to make in order to improve the results.

While I do recognize that, in some cases, it’s possible to tease the actual ROI from a communication investment, most of the time it’s a guessing game to determine just how much money was generated in sales from the social media dimension of a company’s communications efforts. Ultimately, of course, any communication should be designed to support business goals, which at some point translates into money in the bank. But it’s usually impossible to determine exactly how much money, to the penny, fell to the company’s bottom line as a result of social efforts to bolster the firm’s reputation or tout a new product.

Thus, every time we go to executive management and claim we’ve achieved ROI using calculations that are out of synch with their understanding of what ROI is, we undermine our own credibility and reinforce the perception that communications people just don’t understand business.

The thing is, I don’t understand why we’re so obsessed with needing to prove ROI. We don’t. What we need to prove is that we have set objectives for our efforts that support business goals and that those efforts produced measurable results. That’s the kind of reporting that earns management respect and support for investment in communication.

It’s also the approach IABC—the International Association of Business Communicators—has been taking for at least as long as I’ve been a member (since 1977). To assess excellence in communication, IABC wants to know what objectives you set and how you can prove you achieved them. Nowhere does the label “ROI” appear in these criteria. Nowhere does it need to.

Consider, for example, the ongoing participation of several Dell staffers—Richard Binhammer and Lionel Menchaca, for instance—on Twitter. Their availability, their insights, their passion certainly have an impact on perceptions of Dell and the company’s reputation. These undoubtedly factor into decisions to buy. But is there a way Dell’s communications team can express the value of these contributions in precise dollars and cents? Clearly not.

On the other hand, Dell does an amazing job of assessing the shift in the sentiment of online discussion from negative into neutral and positive. The correlation between sales and negative sentiment has been long accepted by the most senior executives in almost every organization. Hence, proving that the communication effort has shifted sentiment is accepted as a valuable effort that supports business goals that lead to sales.

What about cost-avoidance, which I’ve always seen as a useful communication measure? Building strong relationships can prevent tthe need to spend money to address strikes, boycotts, costly legislation or regulation, and the like. Again, occupants of the C-Suite recognize this as valuable, but there’s no way to assign it a formal ROI calculation: Money we didn’t spend doesn’t show up anywhere on a P&L.

So I’m not suggesting that we don’t measure the impact of our social media efforts, nor am I suggesting that we can’t prove that there’s value produced for the resources invested. But for the sake of our own credibility, unless we can come up with the numbers that reflect the way management perceives it, we need to stop trying to claim that it’s ROI.