TL; DR

I have collected a bunch of definitions for the core idea of this effort, i.e., "Credibility." Each of them serves a different use.

My favorite (read: most flexibly useful) definition* is this:

Credibility is a form of validated trust.

You have it–for specific topics and with specific people–to the degree that the trust that you have already earned exceeds the trust that people must extend you for your latest ask.

The greater the ratio, the more credible you are (à la, “this should be an easy ask. After all, I have earned 10x the credibility that people need to extend to me on this ask of mine.”)

Let's look at it one element at a time.

Credibility is topic- and person-specific

A famous architect would not be credible as a circus performer. A Nobel Prize winner would not be credible as a weight lifter.

A member of the Capulet family in Shakespeare's Romeo & Juliet would automatically not consider a member of their enemies, the Montagues, credible. At work, members of a Design team might not consider someone credible on an innovation team if they have a Finance or MBA degree.

Sometimes, credibility (or its lack) is justified. Other times not so much. But it's still real and affects what one can do in the real world.

Credibility is relative

In this definition, I treat credibility as a ratio because it implies the kind of comparison that people often make when they judge someone else's credibility:

If my team has successfully delivered results on budgets of $1 million, then I am credible if I ask for a budget of $10,000 this time. Conversely, I'll have a much harder time earning approval if I have only proven myself with budgets of $10,000 and now ask for a million.

Credibility is directional, qualitative, and subjective but still real

I hope that I don't have to convince you that credibility is a real and important feature of human interaction. If I did, you'd likely not have followed me this far.

But what is worth your while to consider is how precise you can get in your measurement of credibility.

As far as I have found, there are many reliable proxies but very few direct, precise metrics for gauging credibility.

Credibility is:

  • directional: There is a squish factor that allows us to offer a general range of credibility but makes it laughable to put a pin-point-precise number to it. ("I'm pretty credible when I present my annual goals and objectives to our SVP.")
  • qualitative: It is much easier to describe credibility with words and concepts than with numbers. (Nobody has a "credibility of 74.3.")
  • subjective: People will differ in their assessment of someone's credibility in a given situation, vis-à-vis a given other person. ("In my opinion, she is super-credible to him when it comes to decor color choices.")

We can make the definition more specific (and thereby more practical):

Taking a qualitative concept and then attempting to pin it down precisely is playing with fire. The greater the specifics, the more likely it is that you disagree with me in how you'd describe, in this case, credibility.

But I'll offer a more specific definition anyway. Consider this a directional suggestion to spur your own thinking, not an absolute claim to be "right." Then, even if you disagree, it might make you think of something better.

Why even bother?

I have been in situations where I needed to diagnose why the earned trust or trust needing to be extended was what it was. And in those situations, it just helped me to have more details to lean on.

Without further ado then, here is the additional detail level:

Two pseudo-math ratios, each of them describing "Credibility [as] validated trust." Specifics below

In this more detailed version, the nominator of the credibility ratio, "trust earned," is the difference between value you have delivered and the expectations others had of you. Exceeding expectations earns you trust.

And all of that then gets magnified based on the importance of the issue. Exceeding expectations on something that's a massive deal just has a greater impact than exceeding expectations on something trivial.

The denominator, "trust that people need to extend to you in the current situation," is simply the amount of risk that they face in that situation, again magnified (i.e., taken to the power of) the importance of the topic, for the same reason as in the numerator: Taking a big chance on a trivial issue ... is still trivial.

I stayed away from defining "risk" further in the denominator. That's because there are so many types of risk, depending on the situation. The bottom line is always the same though: If you ask people to take a risk on you, you are triggering a credibility check.

How to use this

In my own practice, I've kept the use of this definition very simple.

💡
Simply ask:

"How credible are you on this topic,
and with which of the folks who matter here?"

My logic for this comes from my hundreds of interviews that I lead as a design researcher: Simple but deep prompts can lead people to meaningful introspection. Sometimes, a mere gesture or vocalization can spur people on to dive more deeply into a topic.

In other words, much of the value of considering credibility happens inside people's heads. Your job is mostly to get out of their way and to let them explore the issue.

By all means, offer encouragement. Suggest deeper reflection and greater honesty. But fundamentally, just let individuals or small groups of people wrestle with their credibility. You are a mere conversation facilitator.

Your turn!

How would you change this definition of credibility?

What totally different definitions of credibility have you found useful?

*Bonus! What other definitions of credibility do I find practical?

I like a few other definitions too. They are mostly hacks of other concepts. But they apply to credibility too. So I'll go with it.

Their main benefit is also their main drawback, which is why I don't treat either of them as my go-to definition. Both related to concepts and philosophies from particular fields/ functions. That specialization makes them particularly lovable to people with affinity for those fields but also more alien to others.

From the function of Marketing:

You are credible to the degree that you achieve ...

  • Recency (of credibility-inducing events)
  • Frequency
  • Reach

This, of course, is useful for gauging the amount of credibility you have.

From the discipline of psychology:

You are credible to the degree that others judged you credible in their ...

  • Best (experience with you, your team, people associated with you, or people roughly like you)
  • Worst
  • First
  • Last/ most recent

This helps you consider how much of your "theoretical/ objective right" to credibility translates to subjective human reality, i.e., whether people actually took in what you offered.

And from the craft of management consulting:

You are credible to the degree you can satisfy all three of (i.e., center yourself in the Venn diagram of) ...

  • Problem – Relevance to what they need
  • Solution – Plans that solve their problem
  • Risk – The degree to which they believe you can do it

This is helpful for diagnosing problems with your credibility and prioritizing where to focus improvements.

Even if these definitions don't cut it as primary ones, they still are worth keeping in mind. They remind me that credibility is a multi-dimensional concept that looks utterly different from different perspectives. I must stay aware of both my default perspectives and ones I may barely have considered.

T.I.S.C.


Further reading

"Credibility." (Jun. 25, 2024). In Wikipedia. https://en.wikipedia.org/wiki/Credibility