A Bottled-Water Culture: are we being told what to taste?

 

By: Jordan Fett and Cole Talsma

Statistics (MTH) 210-13, Mr. Todd Swanson

4/24/06

 

 

We’ve all seen the advent of the “bottle water” culture in the last decade. At one point, bottled water was just an “extra button” on the nearest Coca Cola machine. Now entire Dasani machines can be found in many public venues, and almost all the major beverage companies have exploited the opportunity to market water in a bottle under the premise of being cleaner, fresher, and tastier than average tap water. Tap water is still the principle source of water intake; 3.6 of the average daily 8 oz. of water is tap. Bottled water makes up the third largest source of water intake (behind coffee) as 1.7 oz of the average daily 8 oz. intake (1).

           

The tide is rising for the bottled water industry. Despite the fact that of the 89 billion liters of water, 46% is consumed by Western Europe, there has been a much greater demand and industry boom in North America. In fact, North America consumes 20% of the world’s bottled water (2). Bottled water labels such as Aquafina (Pepsi), Dasani (Coke), Perrier (Nestle), Evian, and Fiji have seen a substantial increase in a business that makes upwards of $22 million dollars annually. The change of the century 1999-2000 was witness to the largest known escalation of the industry, a powerful 10% market increase (2).

           

The question remains: why is the bottled water industry is growing so rapidly in the United States considering it is 240-10,000 times more expensive than using exclusively tap water? We asked many of the people here at Hope College who indicated they prefer bottled water why. Their responses confirm the purpose of our investigation.

 

“Bottled water tastes more natural,” one girl responded.  “The stuff is more crisp, tap water tastes like pool water,” remarked one boy. His companion quickly adding, “Plus you know that the chlorine and stuff they put in tap isn’t in bottled water, it tastes more pure.”

 

These statements aren’t all from the traditional advertisements for bottled water. Is it possible that we’re being told that because bottled water is from a “natural underground” spring and purified by reverse osmosis we start to make ourselves taste the difference?

 

On April 19, 2006, Hope students Jordan Fett, 19, and Cole Talsma, 19, set out to investigate this very phenomenon. Using the latest advances in water-carrying devices researchers carted 3 gallons of fresh water to a high-traffic location on campus. A table outside of Phelps Dining hall during dinner hours was assembled. On this table, they set out three groups of Dixie cups, fifty cups per group for a total of one hundred and fifty Dixie cups. One group was labeled “Tap Water”, the second “Aquafina” (a popular bottled water brand), and the third “Imported Water” (with an artificial brand name that was described as an expensive French imported water). Unknown to the students participating in this tricky taste test all of the Dixie cups were filled with Hope College tap water! As students randomly filed through the door to Phelps they each recorded on a 1-10 scale their opinion of each “water type”. The results were astounding.

 

 

As this set of box plots reveal, the students had a dynamically increased preference for both bottled and imported water over tap water. A closer examination of the score distributions for each type highlights some of the trends we noted during the survey.

 

 

A histogram revealed that while some people did consider the tap water good to excellent (approx. 7-10). Many didn’t approve of the taste of tap water. This may be due to a preexisting bias. Some people approached this section with remarks such as, “Ugh, I hate tap water.” Or, “I have to warn you, I never drink tap water so I might not score it high”. This dropped the mean score for tap water to a miniscule 4.68 (SD 2.35).

 

 

 The histogram of the “Aquafina” water reveals a dynamic shift from the previous graphic. When people were told they were drinking Aquafina, many scored it well above the middle, 5. One student in particular exclaimed after lamenting the taste of the “tap” water, “Thank God you have Aquafina, I love Aquafina!” It should be noted that no one scored the “bottled water” as being a perfect 10. The mean score for bottled water was a respectable 6.14 (SD 1.94).

 

 

 The histogram for the “Imported” bottled water further demonstrates the previous phenomena. Where the previous graphic seemed to have a more normal distribution, people’s opinion of tap water when told it was imported was greatly skewed to the right. The average score for the “imported” water was a towering 8.01 (SD 1.78).

 

In order to test whether or not a relationship could be inferred, the student researchers needed to perform a test called a Chi-Squared test. This would test against the null hypothesis that there is “no relationship between score and water type”. The statistic gained from this test (or Chi Squared value) was 60.63 and the p-value was less than 0.0001. Because the p-value was less than 0.05, we can conclude that there was a relationship between the score of the water type and the water “type” used.

 

Researchers decided that a score of 7-10 was adequately high enough to consider a “Good to Excellent” rating. In order to support these conclusions statistically, a 2 proportional T-test was administered to the collected data. This test compares two proportions against the other to see if the first is significantly (statistically significant, that is) higher or lower than the second. Of the people testing tap water, 14 out of 50 thought it was good-excellent. This was compared to 24 out of the 50 people who believed the “bottled” water was good-excellent. These proportions were compared at a significance level of 99% with the alternative hypothesis that a greater proportion would favor bottled water. The p-value elicited from this test was 0.02. Because this p-value is less than 0.05, we could conclude with 99% confidence that a significantly larger proportion of people believed “bottled” water was better than tap water.

 

Researchers continued their investigation by comparing the proportion of “bottled” water to “imported” water. 40 out of 50 respondents believed “imported” water was good-excellent. The same test of significance was used, producing a p-value of less than 0.0001. Because this p-value is less than 0.05, we could conclude with 99% confidence that a significantly larger proportion of people believed “imported” water was better than “bottled” water.

 

“It just tastes crisper,” one student commenting when he took a sip of the tap water we labeled as being imported from France. “So you like it?” researcher Cole Talsma inquired. “Like it? I don’t know where you guys got this stuff, but it’s good stuff,” the student answered. “The data speaks for itself,” student Brendan Krueger commented when observing the results of the study. When given the exact same water, students were inclined to believe the words on the signs in front of them before they were willing to trust in their own taste buds.

 

 

 

 

Appendix:

 

Table 1: This table of data is organized by score and water type.

 

Water Type

1-2

3-4

5-6

7-8

9-10

Tap

11

14

11

13

1

Bottled

2

6

18

20

4

Import

3

2

5

16

24

 

 

     

 

 

 

Table 2: Total Raw Data

 

Respondent

Tap

Bottle

Import

1

6

7

9

2

4

8

9

3

3

2

7

4

3

5

9

5

3

8

9

6

8

6

6

7

5

7

7

8

2

8

8

9

1

7

10

10

8

8

8

11

3

6

10

12

4

7

9

13

5

8

10

14

8

7

8

15

3

5

9

16

8

7

8

17

7

5

4

18

5

9

10

19

5

3

9

20

5

5

6

21

8

7

8

22

2

6

10

23

1

5

7

24

6

1

7

25

4

4

9

26

5

5

10

27

4

9

6

28

9

5

7

29

2

5

7

30

5

7

8

31

2

2

7

32

3

5

9

33

1

8

9

34

4

8

10

35

4

6

9

36

2

9

7

37

7

7

7

38

8

7

10

39

2

4

8

40

3

8

9

41

8

8

8

42

7

5

9

43

8

3

4

44

5

5

6

45

7

6

2

46

8

7

10

47

2

6

8

48

2

8

9

49

4

9

10

50

5

4

5

 

 

Sources:

 

(1)    Bullers, A.C. 2002. “Bottled Water: Better than Tap?” FDA Consumer Magazine. Jul. www.fda.gov <http://www.fda.gov/fdac/features/2002/402_h2o.html#>

 

(2)    Klessig, L. 2004. “Bottled Water Industry” Unviersity of Wisconsin-Eau Claire.< http://academic.evergreen.edu/g/grossmaz/KLESSILL/ >