---
url: "https://questionstar.com/principles-of-survey-research/chapter-6/slide-241.html"
title: "The Role of Perception"
type: "lehrbuch-slide"
chapter: 6
chapterTitle: "Advanced Techniques of Market Analysis"
slide: 241
---

# The Role of Perception

*The same respondents, the same colas — only the knowledge of the brand changes. The preference flips:*

The same respondents, the same colas — only the knowledge of the brand changes. The preference **flips** :

![Diet Pepsi](/principles-of-survey-research/media/can_pepsi.png)

![Diet Coke](/principles-of-survey-research/media/can_coke.png)

### Blind test

Respondents don't know which cola they are drinking

Diet Pepsi

51 %

Diet Coke

44 %

No preference

5 %

### "Open" test

Respondents know which cola they are drinking

Diet Pepsi

23 %

Diet Coke

65 %

No preference

12 %

Blind, **Pepsi** wins — with brand knowledge, **Coke** wins. It's not the product that decides, but **perception** .

---

*Slide 241 of 274 · Chapter 6: Advanced Techniques of Market Analysis · Principles of Survey Research · Dr. Paul Marx*