Taste Preference of Soda in the - Lab Report Example

Pepsi and Coke equally preferred by the graduate Double Blind Trial; Pepsi and Coke equally preferred by the graduate Similar carbonated beverages can be seen in the market under different brands and the consumer demand is highly varied. It is questionable whether consumers prefer one brand over another due to their taste or due to any other influential factors such as brand. This study was carried out to Identify whether there is a significant preference for the taste of Coke over Pepsi among graduate students. Seventy two students were selected and their preferences were recorded. They were invited to participate in a double blind taste trial (consisted of 12 replications) where the brands were not shown. Each trial consisted of 12 replications. Group data was analyzed by Z test and T test and Individual data was analyzed by Sign test and Binomial distribution. Result of group data analyzed by both methods did not show any significant preference (p> 0.05) deviated from the null hypothesis of equal chance at the level of significant 0.05. However some individual data showed a significant preference to the taste of Coke over Pepsi. In conclusion this group of graduate students seems to like both brands equally. Double Blind Trial; Pepsi and Coke equally preferred by the graduate students Introduction Today many brands of carbonated beverages (sodas) can be seen in the market. Different manufacturers produce closely similar competitive products but in different brand names. Well known examples are Pepsi and Coke and Mirinda and Fanta. Although these products seem to have similar, properties consumer demand is highly varied. Consumers are most likely to attract to those products due to their taste. However in psychological studies there can be many factors that make consumer select a food or a beverage over similar product other than taste (Pierce & Belke, 1988). It has been found that the product brand can influence the consumer’s perception towards a particular product irrespective to its quality, taste, texture or any other aspect (Pierce & Belke, 1988). Today the highly competitive manufacturers gain reputation for their branded products by exaggerating the features and hiding any adverse effects and by increasing the frequency of advertising. A consumer who is being exposed to these types of advertisements for a considerable time may perceive a positive idea about the product (Pierce & Belke, 1988). It is really important and interesting to find how taste per se affects the consumer preference when other influential factors are blocked. This will also helpful to measure the impact of other influential factors such as advertising and cultural influence. Many consumer surveys on taste preferences had been conducted and results were interpreted but mostly by the producers themselves. There is a potential biasness in those interpretations since those were done completely for commercial purposes. Further, use of scientific methodology and application of appropriate statistical analysis in these surveys are not very clear. Usually these types of surveys gather data from self answered questionnaires collected from un-blinded participants or single blind market trials like “Pepsi Challenge”. In most taste surveys consumers are given beverages only once where the effect of order is not concerned (Dean, 1980). Well planned, methodical scientific studies and interpretations conducted by professionals are still lacking in this area of taste preference. Therefore necessity aroused to conduct a scientific research on taste preference. This study was conducted to determine the consumer preference for the taste of one band of soda over another. Pepsi and Coke, most popular and well known competitive brands were selected for this study. The objective of this study was to find out whether the consumers show a significant preference for the taste of Coke over Pepsi. The Hypothesis used in this study was; Consumer preference for the taste of Coke is significantly higher than that of Pepsi. Method Subjects The sample was consisted of 72 undergraduate students. Selection of the sample All the students who were present on the day of the experiment were selected from a classroom in a graduate school. Subjects who did not like soda or have shown allergic reactions to soda were excluded. All the participants were asked to meet in the classroom at 1.30 pm. Product preparation For this particular study caffeine-free Pepsi and caffeine-free Coke were used as the two brands of soda. Beverages were not cooled and provided at the room temperature. Beverages were named as A and B and the identity was not revealed to the participants till the end. Procedure Seventy two students reported the classroom at 1.30 pm and they were advised to get into pairs. Each pair was provided two taste test forms to interview each other. Further they were given two cups containing 3 oz from each beverage. Cups were marked as A and B, but the brand name was not mentioned. During the experiment one had to be the experimenter and other had to be the participant. At the end of the first trail (consisted of 12 replications) they were asked to exchange the roles and conducted the second trial. This was a double blind taste trial in which the both experimenter and the subject were unaware of the brand of the Soda. Each pair seated confronting each other beside a table. First, the experimenter asked the subject which soda he or she prefers (i.e. Coke, Pepsi or No preference) and the answer was recorded in the form one. Then the experimenter asked the subject to close his or her eyes. The subject was then given A and B (according to the pre planned order provided in the form) and asked to take a sip from both. Then subject had to express his preference to the first one or second. Throughout the process subject was advised to keep the eyes closed, there by he or she cannot see the letters on the cup. The procedure was repeated for another 11 times and the answers were recorded. Then the whole trial was repeated and answers were recorded in the second form after exchanging the roles. Statistical Analysis Data was entered in to an Excel spreadsheet. The probability of preference for Coke, Pepsi or No preference was computed. SPSS 10.0 statistical package was used to confirm whether the group data was normally distributed. Statistical analysis performed using four methods. Method 1: The objective of this method to find out any statistically significant difference in preferences to the Coke over Pepsi in this study group (72 subjects) before the experiment. Probabilities of preferring Coke, Pepsi or No preference were computed and Z Test was performed using below equation. P-Po Z= _____________ √Po(1-Po) √ n Related probability for derived Z value was found compared using the Table of the Standard Normal (z) Distribution Method 2: The objective of this method was to find out any statistically significant difference in the preferences for the taste of Coke over Pepsi in this study group (72 subjects) based on the results of the experiment. Probabilities of individual participants for preferring Coke was computed. Mean and the Standard Deviation of the individual probabilities were also computed. Student’s T-test (two tailed, independent sample) was performed (using MS Excel) to compare the mean probability of the study group with the null hypothesis (i.e. probability of selecting Coke is 0.5). Method 3: The objective of this method was to find out any statistically significant preferences for the taste of Coke over Pepsi in a given individual data consisted of 12 replications. Sign test table was used (n=12, s=2) to derived the individual probability. Method 4: The objective of this method was to find out any statistically significant preferences for the taste of Coke over Pepsi in a given individual data using Binomial Distribution. Results In this study 72 undergraduates participated and each subject expressed their preference to one of the drinks (Coke or Pepsi) for twelve times (12) after tasting them. Therefore to analyze the group data n=72 was considered and to analyzed individual data n=12 was considered. For statistical calculations probability of null hypothesis was taken as 0.5 Figure1: Frequency of the number of times each individual selected Coke Each individual had selected Coke from 0 to 12 times from total 12 consecutive tests. Above figure shows the population frequency for selecting Coke, number of times ranging from 0 to 12. This was normally distributed. Therefore T test can be used for comparison. Mean number of times selecting Coke in this study group was 5.46 with the Standard Deviation of 3.02. Mean probability for selecting Coke in this study group was 0.46 with the Standard Deviation of 0.25 Method 1: Group preference for the taste of the Coke Table 1: Preferences of the Study group prior to trial Number of subjects fall in to 3 categories of preferences and the probabilities are shown in the above table. Figure 2: Preferences of the study population as a percentage Above figure explains the preference of study group for the taste of Coke, Pepsi or No preference as a percentage. Z test was performed to find out whether the study population significantly prefers Coke deviating from the null hypothesis (equal preference) Computed z value was 1.188 and the related probability (area underneath the curve) is 0.3810 (at 0.025 level) and statistically not significant at 0.05 level. Method 2: Observed group preference for the taste of Coke Figure 3: Comparison of observed and expected means of number of times and probability of selecting Coke T-Population Mean and Standard Deviation of the Number of times Coke was selected P- Population Mean and Standard Deviation of the probability of Coke was selected In figure 3, first bar (in blue color) shows the mean number of times that the Coke was selected by the group and the standard deviation. Second bar (pink) shows the null hypothesis (i.e. 6 out of 12 times). Third bar shows the observed mean probability of selecting Coke by the group. Forth bar shows the probability of the null hypothesis (i.e. 0.5). T test was performed to find out whether the study population significantly selected Coke deviating from the null hypothesis. T test results (p=0.13) which was not significant at 0.05 level shows this study group has not statistically significant preference for the taste of Coke. Method 3: Analyzing an individual data using sign test Result of an individual trial was analyzed to find out any significant preference. This individual has expressed preference for the taste of Coke 10 times out of 12 trials. According to the Sign test table the probability of this individual trial was 0.019 which is clearly significant at the 0.05 level (p0.05) explains this study group does not have significant preference for the taste of Coke over Pepsi or they like both beverages equally. In this study both pre-test preference and taste test results showed their equal preference for the taste. Therefore it can be assumed as these subjects were not influenced by the other factors such as brand or advertising. However the individual data analyzed using both Sign test and Binomial distribution expressed a significant preference for the taste of Coke over Pepsi. As mention by Dean (1980) order of providing the beverage has effect over the preference of the subject. This can be due to “palate desensitization” and “attention decrement”. To avoid any biasness occur due to order of providing the beverages, order was altered according to a pre planned schedule. However “palate desensitization” and “attention decrement” is still possible due to consecutive 12 trials done within a short period of time. To improve this study, trials can be done in separate days or after a considerable time period. Another study done by Woolfolk et al (1983) revealed that their study group’s preference was influenced by the label of the bottle than the actual content. Since the brand names or labels were not shown in this study above effect cannot be weighed. Although this study was methodical than commercial trials for a better outcome need some improvements. Tasting is a highly sensitive process. The taste, feel by the consumer can be affected by temperature of the drink, time keeping in the mouth, area of the tongue touched by the beverage, speed of drinking, nasal obstructions which can block the flavor and many more (Peynaud, 1996). One weak point in this study was, trials were preceded without washing the mouth. Therefore there was a chance to remaining of the earlier beverage mix and alter the taste of the next beverage. Further the drinks were not cooled due to lack of facilities. However the temperature of the beverage affects the taste. Smokers, pregnant women, people in a regime of drugs were not excluded. But those can alter the taste as well as the foods that had been eaten just before the trial. On the other hand decision making is a very complex process in the brain. When the consumer is asked to name one drink he/she prefers most from given two drinks with nearly similar properties brain draws information from many other aspects than taste (Myers, 1962). These can be smell, early experiences, color, and room temperature. Similar properties of two beverages might have influenced customer for a random selection. Further to above this sample does not represents the general public. The age, Psychological aspects, likes dislikes to food and beverages may differ from the general population. Therefore these findings cannot be generalized. This was a double blind trial, in which the experimenter and the subject do not know the brand. Therefore there was very little or no chance for the experimenter’s biasness. Further this was not conducted by persons involve in manufacturing or for commercial purpose. In conclusion, Pepsi and Coke equally are preferred by the college students. Further improvements should be done and additional components should be added for a more reliable outcome. References Dean, M. L. (1980). Presentation order effects in product taste tests. The Journal of Psycology, 105: 107-110. Myers, L. B. (1962). Introduction to Type: A description of the theory and applications of the Myers-Briggs type indicator, Consulting Psychologists Press, Palo Alto Ca. Pierce, W. D., Belke, T. W. (1988). Stimulus control of consumer opinion by brand names: A school conditioning analysis. The Psychological Record, 38: 227-236. Peynaud, E. (1996). The Taste of Wine: The Art and Science of Wine Appreciation, London: Macdonald Orbis. Woolfolk, M., Castellan, W.,Brooks, C. (1983). Pepsi versus Coke: Labels not tastes, prevail. Psychological Reports, 52: 185-186. Read More