Consultant Emily Alexander recently attended the HFES Healthcare Symposium’s and participated in the poster session where she shared her framework for capturing root causes using Plinko from daytime gameshow The Price is Right.
Curious? Here is a summary of her framework.
The importance of root cause
Root cause is the most important information human factors practitioners can gather during a medical device usability study. Without it, we fail to gain actionable insights on how to improve usability, and subsequently improve the safety of medical devices.
There are so many things to juggle when moderating a human factors study that make it difficult to know if the appropriate root cause has been gathered in the moment. Human factors practitioners need to ensure they don’t end a root cause debrief discussion too soon as they could miss gathering valuable insights on how to improve a device or lack the detail needed to address residual risk. And once the participant leaves the room, you can’t get them back.
Human Factors Plinko
The Plinko framework helps human factors practitioners visualize root cause conversations with a fresh perspective on a routine aspect of HFE work.
In Plinko, contestants release chips at the top of a vertical Plinko pegboard to eventually land in slots at the bottom of the board corresponding to a prize amount. Sometimes, a chip may become stuck or take an unexpected path to the bottom of the board, not unlike the path of a root cause conversation with a study participant.
Using the Plinko framework to uncover root cause
Before the study
Step 1: Identify your Plinko slots
Identifying possible root causes ahead of time can help you feel more confident as the moderator going into your study. On the Plinko board, these categories are located at the bottom of the board with each root cause representing a separate slot.
Step 2: Understand Plinko slots in terms of the device being studied
The next step in study preparation is to envision how your chips might fall into each slot at the bottom. Review each of the potential root causes and consider what might cause a participant to provide that root cause as it relates to your device and study.
Step 3: Review risk documentation for correlation with Plinko slots
It’s important to familiarize yourself with potential use errors that have been identified in the Use Related Risk Analysis (URRA). By pre-evaluating use errors listed in the risk documentation, you can determine which use errors are likely to fall into certain categories and this can help inspire what root cause questions to ask ahead of time.
During the study
Step 1: Play Plinko by conducting root cause
Your participant has just given you several Plinko chips in the form of observed use errors during the study and it’s time to root cause. The questions you ask during root cause represent the pegs on the Plinko board. When a chip hits the pegs, it changes direction. Do this enough and your Plinko chip will land in a slot at the bottom of the board, the ultimate goal for root cause.
Step 2: Confirm the Plinko chip landed
Ask yourself: Why did the participant make this error?
If you can’t answer this question using feedback the participant has provided, your Plinko chip hasn’t yet successfully landed in a slot and you need to continuing asking root cause questions. Remember, Plinko chips are unpredictable so you shouldn’t assume you know where the chip will land. Instead, rely on what the participant is telling you.
Step 3: Gather residual risk rationale as needed
During a formative study, gathering details to build risk rationale is an optional step and might be skipped if early in the design process. As the device gets further in the product development cycle, and especially during a summative study, it helps to build a case as to why design changes might be avoided.
After the study
If your Plinko chips landed in slots at the bottom of the Plinko board, you’re a winner!
After a Formative Study: Inform Actionable Change
Plinko chips that landed in slots at the bottom of the Plinko board during a formative study represent opportunities for actionable change and improvements, especially before a summative study.
After a Summative Study: Inform Residual Risk
Review of the information gathered during the study will either support residual risk rationale in a summative report or highlight the need for further design changes to improve usability.
Conclusion
The Plinko methodology presented here is a tool for study moderators to work through root causing use errors observed during a human factors study. By using this framework, human factors practitioners ensure valuable insights are gathered regardless of study type: design changes powered by user voice during a formative study or details imperative to address residual risk improving the chance of FDA approval following a summative.
Want to learn more? Explore the detailed presentation of this framework.
Need help with a study? Let’s connect. Send us a note at info@consultfathom.com.
