Short answer
When using physical models or analogies to explain technical concepts, rigorously test their properties to ensure they accurately reflect the principles being communicated.
- Field
- Classic Design
- Source
- BMJ (2007)
- Method
- Observational study
- Sample
- 20 chocolate bars (10 Crunchie, 10 Aero)
- Evidence
- Strong effect
The physical properties of common chocolate bars, like Crunchie and Aero, do not accurately represent the complex biomechanics of bone fracture, making them unsuitable analogies for patient education. This classic design research insight is drawn from a 2007 study published in BMJ. Using Observational study with 20 chocolate bars (10 Crunchie, 10 Aero), researchers explored how this design variable affects real-world outcomes. The key design takeaway: When using physical models or analogies to explain technical concepts, rigorously test their properties to ensure they accurately reflect the principles being communicated.
Chocolate bar properties do not reliably model bone fracture mechanics
The physical properties of common chocolate bars, like Crunchie and Aero, do not accurately represent the complex biomechanics of bone fracture, making them unsuitable analogies for patient education.
BMJ · 2007
Key Findings
- 01Both Crunchie and Aero bars showed similar T and Z scores for bone density.
- 02Crunchie bars had a lower chocolate mass index than Aero bars.
- 03Crunchie bars were more prone to fracturing.
Application
Design takeaway
When using physical models or analogies to explain technical concepts, rigorously test their properties to ensure they accurately reflect the principles being communicated.
How to apply
Before using a common object as a model in a design project (e.g., for user testing, educational materials, or conceptualization), conduct a brief analysis to confirm its relevant properties align with the intended representation.
Project actions
- 01When choosing a model or analogy for your design project, think about whether it actually behaves like the thing you're trying to explain.
- 02Don't just pick something because it looks similar; check if its properties are right.
Method & Evidence
Variables
Strengths & Limitations
Strengths
- +Uses readily available and relatable objects.
- +Directly tests a common, albeit flawed, educational approach.
Limitations
The study only looked at two types of chocolate bars and didn't consider how people might react to seeing chocolate used as a bone model.
Reliability & validity
The study's validity lies in its direct testing of the analogy's physical properties. Reliability would depend on consistent measurement of 'bone density' and fracture points across multiple samples of each chocolate bar type.
Think critically
What other everyday objects might be tempting to use as analogies but could lead to similar misunderstandings in a design context?
Design Principles
"Analogies must be functionally representative, not just visually or superficially similar."
Designers often use familiar objects to explain complex concepts. This research highlights the critical need to validate the chosen analogies, ensuring they accurately reflect the principles they aim to illustrate, rather than relying on superficial similarities that can lead to misconceptions.
What This Means for Your Design
Using chocolate bars to teach about bones doesn't work because the chocolate breaks too easily and doesn't act like a real bone.
How to use in your project
- 1.Reference this study when discussing the selection and validation of physical models or analogies in your design process, particularly if your project involves explaining complex systems or educating users.
Add to My Project
Quick Cite
Paragraph starter
The selection of physical analogies for design communication requires careful validation. Research by Vreeman and Carroll (2007) demonstrated that common objects, such as chocolate bars, may not accurately model complex physical phenomena like bone fracture mechanics, leading to potential misconceptions. This underscores the importance of ensuring that any chosen models or analogies in a design project possess properties that genuinely reflect the principles they are intended to represent.
Source
Questions About This Research
- What does the research say about chocolate bar properties do not reliably model bone fracture mechanics?
- When using physical models or analogies to explain technical concepts, rigorously test their properties to ensure they accurately reflect the principles being communicated. Evidence: BMJ (2007).
- Why does "Chocolate bar properties do not reliably model bone fracture mechanics" matter for design?
- Designers often use familiar objects to explain complex concepts. This research highlights the critical need to validate the chosen analogies, ensuring they accurately reflect the principles they aim to illustrate, rather than relying on superficial similarities that can lead to misconceptions.
- How can designers apply this research?
- When using physical models or analogies to explain technical concepts, rigorously test their properties to ensure they accurately reflect the principles being communicated.
- What were the main findings?
- Both Crunchie and Aero bars showed similar T and Z scores for bone density.. Crunchie bars had a lower chocolate mass index than Aero bars.. Crunchie bars were more prone to fracturing.
- What research method was used?
- Observational study with 20 chocolate bars (10 Crunchie, 10 Aero).
- How strong is the evidence?
- Evidence strength is rated Strong effect, based on a 2007 journal from BMJ.
- What should I do differently in my next project?
- Before using a common object as a model in a design project (e.g., for user testing, educational materials, or conceptualization), conduct a brief analysis to confirm its relevant properties align with the intended representation.
- What are the limitations?
- The study focused only on two specific chocolate bar types and did not explore other potential analogies or the psychological impact of using such analogies.