This is the first of a series of blogs that will detail each of the biases that can cause us to take mental shortcuts, resulting in sometimes less than optimal cognition.

First up: The Anchoring Bias

What is anchoring bias?

Anchoring bias happens when we base our judgments on initial information rather than waiting for a complete picture. It’s like forming an opinion at first glance rather than reserving judgment until all data is considered. This blog post explores the implications of anchoring bias and how to avoid it in decision-making.

Engineers often feel that in-person observations provide the best data. While this may be true sometimes, in some aspects, it can actually be counterproductive. Think of it like navigating a city: walking every street to memorize each turn is far less efficient than using a map. A map allows us to form a mental model that’s quicker and often more accurate. Similarly, in engineering, using comprehensive data, like floor level measurements and stress indicators, helps us build a clearer, more cohesive understanding of the structure than in-person observations alone might provide.

Similarly, analyzing three-dimensional floor-level data combined with stress indicators and other measurements allows us to build a more cohesive model of a structure—often more accurate than an in-person inspection. By withholding conclusions until all data is considered, we can avoid premature judgments and make more informed decisions.

Project Example

I recall working on a project many years ago in the city of Glendale on a typical slab-on-grade construction or three-pour foundation system. The engineering team did a great job in gathering the information, arriving at a conclusion, and developing a well-supported repair plan. We proceeded through the permitting process and then started to work. 

One of the key cultural values I wanted to establish in my company was encouraging everyone, at every level, to ask questions and speak up if they felt something wasn’t right. However, sometimes this resulted in workers in the field, who once they got a little understanding, engaged in the Dunning-Kruger effect, where they felt they knew more than the engineers… and that is what happened in this case. 

In this particular case, we sent our moisture level team out to remediate what was properly diagnosed as a severe heave on the south portion of the home. One of our workers arrived and looked at the damage, saw the cracks in the walls and the gaps under the walls near the perimeter walls, and concluded that the perimeter was settling. He also noted a significant floor crack parallel to the South wall, with a noticeable drop on the side closer to the perimeter wall. See pics below.

Onsite Data that Resulted in Hasty Thinking

From this perspective, it would be easy to conclude that the exterior wall had settled, especially given the floor crack with a shifted elevation running parallel to it.

The exterior damage near the area of concern seemed to support the idea of settlement. However, further data provided a clearer picture.

Looking at More Data

Below is the 2D-floor elevation survey. Notice the green line running parallel to the south wall. There was a noticeable drop in the crack on the side of the slab closer to the wall, which aligned with the gap under the interior wall.

By examining the 2D version, an experienced forensic engineer could begin to piece together that these damages align with high areas. This suggests that the issue was more likely due to heave, not settlement. If we’d already anchored ourselves to the idea of settlement, we’d experience cognitive dissonance as we reconsidered this new perspective, ultimately overcoming the anchoring bias.

This installer took it upon himself to stop the project and tell the homeowner that this was improperly diagnosed and that what they really needed was the installation of piers. At that point, I got involved to understand the problem more thoroughly. I’d like to know if our engineering team got it wrong and, if so, why. However, looking through the data, it became very clear to me that the prima facie evidence of looking at the damage on the site is very deceptive and would lead a person to the wrong conclusion.

Unfortunately, our worker lacked the tools necessary to fully analyze the situation and was caught between conflicting perspectives, making it difficult to weigh the evidence accurately. 

The Advantage of Having 3D Models

Looking at the 3D model of the home, it’s clear that the distress on the east end was not caused by settlement. This model provides visual data that simply walking through the rooms cannot offer, allowing for a more accurate understanding of the structural issues.

Wider Implications in the Foundation Repair Industry

This example highlights the risks in the foundation repair industry when sales reps without training in geotechnical mechanics or structural analysis are tasked with diagnosing issues. Relying solely on visual inspections, basic elevation readings, or a simple 4-foot level to assess flatness is insufficient. I’m fairly confident that 99% of sales reps in this industry would have recommended piers to fix this problem—a solution that would have been entirely incorrect. While you could attempt to pier the entire house and raise it to the highest point, this would come at significant expense and risk. If the heave continued, the same issues would reappear.

Overall, this is a powerful example of why it’s essential not to jump to conclusions based on initial impressions. In-person observations alone can be misleading, and only by utilizing all available data can we gain a complete understanding of the situation.