The internet has made the collection of big data ubiquitous. Everywhere we go online is tracked and analyzed, then reflected back to us in the form of ads and other marketing. Most of us are ok with this, maybe a bit uneasy, but overall understanding that this is simply the way the internet works (let’s leave privacy and politics aside for the sake of this post).

When it works really well, we celebrate it—I don’t know how Spotify does it, but my Discover Weekly playlist is always incredible. When it goes wrong, or shows us an ad that hits a soft spot—an ad for a gym when you’ve just gained 10 pounds, or an engagement ring just after a breakup—it feels invasive, and a little bit gross.

Big data can get pretty close, but it can’t tell the whole story. Online, we are filtered versions of ourselves, and those filters become amplified through social media. I don’t know about you, but I pick the best photos for Instagram, try to Tweet only my funniest insights, and use Incognito mode if the urge strikes me to check up on an ex, or search something I don’t want coming back to haunt me.

The same principle applies to work. We present the polished version of ourselves to our colleagues and managers, filtering our communications for the circumstances, dressing a certain way, and tempering our emotions. Of course, organizational culture varies widely, so this might look a bit different depending on the workplace, but I believe it’s quite common.

As Martin Lindstrom claims in his book Small Data, “in my opinion, the best, closest approximation of who we are as humans comes from mixing our online and offline selves, and from combining big data with small data. Considering that 90 percent of what people give off in conversation are nonverbal signals, our truest identities can be found by studying who we are in our real lives, cultures and countries.”

Consultants and coaches want to give their clients measurable results, so it makes sense to start with the big numbers. Employee surveys, year end performance review data, sales metrics, and customer churn rates, are all important numbers to look at (and strive to improve).

But if you rely on these numbers alone, you may be missing an important piece of the puzzle.

Is your client struggling with culture? Have a look around their office. Do employees have photos of their family on their desks? Or are their workspaces cold and impersonal? That tells you more than an employee engagement survey. Sales figures slumping? Talk to a former customer. Maybe a glitch on the website made reordering difficult, they outgrew the product, or felt a stronger emotional connection to a competitor. That information won’t show up on a sales report. High staff turnover? A look around the office at the beginning and end of the day may show you that everyone is struggling with rush-hour transit, and are secretly wishing for flex hours or a work from home day.

Depending on the method of collection, big data can also be a lagging indicator. A yearly engagement survey is a nice way to take the pulse of an organization, but a lot can happen in a year, and the data can quickly become obsolete. Observing the dynamics of an organization in the moment can give you a leading indicator of where to focus your attention.

I’m not suggesting that you ignore the big data altogether. Instead, it’s worthwhile to examine both the big data and the small data to figure out what the right data is to solve the issue.

HBR recently wrote about how Uber has excelled at this. Uber focuses on collecting location data, in order to dispatch cars effectively—they honed in on the information needed to make decisions, and massively disrupted an entire industry.

In the foreword to Small Data, Chip Heath claims: “new ideas typically come from juxtaposition—combining two things that previously haven’t been combined. But Big Data typically lives in databases that are defined too narrowly to create insight.”

It would be foolish to ignore the big data that is now so readily available. But it’s important to pay attention to the small data as well, to create opportunities for juxtaposition and insight. As the saying goes, sometimes the devil is in the details.