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We conducted a taste test to determine if people can distinguish between Hershey's and off-brand chocolate. Our experiment revealed that 68% of participants could, with a 12.9% margin of error at a 95% confidence level. Females performed better than males in distinguishing the difference. The data supports the claim that Hershey's chocolate has a distinct taste.
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Tim Beasock Dominique Coy Zach DeWolfe Maria Zumpano
Our Purpose • After surfing the internet we found on the Hershey’s website they say their chocolates “…are a globally renowned American icon, celebrated for their distinct chocolate taste…”. (Hershey’s) • Therefore, we tested the accuracy of this statement by testing whether or not one could taste the difference between Hershey’s and an off brand. *We decided to use Hershey’s Bells and the generic chocolate bells because we would have two types of chocolate that looked almost identical.
Hypothesis’ Our Null Hypothesis (Based on the Hershey’s Website) Ho: p=50% Our Alternative Hypothesis (Based on what we think) H1: p>50% Level of Significance (What we chose) α = 5%
Who we Tested • Our population was “VVS High School Students” with a sample size of 50. • We chose the sample size of 50 because due to the Central Limit Theory/Large Sample Method, the number size was appropriate.
The Procedure • We went to the Guidance Office to obtain a list of all the students in the VVS High School. • We then random generated 100 numbers using a graphing calculator. • After that, we completed our sampling process by noting the student on the list from Guidance who corresponded to the number generated. • Ironically, we random generated 25 males and 25 females.
*Note* We generated more than our sample size and chose the number 100 to account for: 1) if a number was generated more than once (we weren’t going to sample the same person twice) 2) if a number generated corresponded to a member of our group (for this would create bias) 3) if a person chosen refused to do the sampling (ie. for allergies, diet) *When generating numbers, one corresponded to a member of our group, so we disregarded that number because it would have created bias. Also, there were two people chosen who could not participated, one due to allergies and one who didn’t want to. We then went to the next numbers chosen.
The Experiment • We went to the sampler during their lunch/free period (we obtained a list from Guidance telling us each of those periods for each sampler) • We approached each person and asked for their permission to do the sampling and if they were allergic to chocolate. • We then verbally told them exactly what they were going to do. “With your eyes closed you are to: 1) Eat the piece of chocolate from Cup 1. 2) Drink a cup of water *note* (the amount in each sampler’s cup was exact; Zach filled each one) 3) Eat the piece of chocolate from Cup 2. 4) Tell us which piece you believe is Hershey’s or if you do not believe there is a difference/can’t tell, you have that option.” • The samplers then did the sampling and we recorded our data in our data table. • We did not reveal to any participant if they were correct. *This was to eliminate bias*
Based on the data from our experiment, 68% of people in the sample could distinguish the difference between Hershey’s chocolate and the off brand, and likewise, 32% could not.
Here, the data from our experiment was subdivided into the grade levels.
Subdivided by grade level, here are the percents of each grade, Correct vs. Incorrect.
The data was then divided into categories based on gender to see whether male or females could distinguished the difference more accurately. Females could distinguish the difference better than males.
All the Math… Our experiment indicates that 68% can tell the difference between Hershey’s and an off brand with a 12.9% Margin of Error at 95% Confidence Level.
p-value (taken from table) .oo54 Level of Significance 5% or .05 .oo54<.05
Conclusions • Our np>5 and nq>5 came out okay, thus, our sample size was alright. • Our experiment indicates that 68% can tell the difference between Hershey’s and an off brand with a 12.9% Margin of Error at 95% Confidence Level. • At 5% Level of Significance, our data is sufficient enough to reject Ho and accept H1; people can tell the difference between Hershey’s chocolate and an off brand.
Evaluation On the whole, our project went very smoothly. We completed it in the time period we had planned for and we also successfully found every person on our list we had random generated. Our plan worked very well for we ran into no problems during our experiment.
Biases Unfortunately bias is almost impossible to eliminate completely in an experiment… The Unavoidable Biases • How often they eat chocolate “Chocolate Lovers” vs. Non “Chocolate Lovers” • The samplers telling other people about the experiment and their choice. It is the characteristics of a person to share when they do something out of the ordinary. • People who didn’t really know the difference but said they did It is human nature for one to want to have answer. The Avoidable Biases • Two people sampling at the same time Created bias because the first samplers decision could have influenced the second; *however, we did not tell them if they were right or wrong* • Different person conducting the sampling All four members of our group conducted the experiment; we knew which cup contained Hershey’s • Hershey’s chocolate was in Cup 1 and the off brand was in Cup 2 throughout the whole experiment. Although they drank water in between, it raised the question “was that enough to eliminate bias?”.
Modifications on Our Project Although our sample size was sufficient for the Large Sample Method and Central Limit Theorem and worked alright, increasing the sample sizewould be something we do differently next time. This would make our results more accurate and our Margin of Error lower. Blindfolding the sampler when they were tasting the chocolate would be another thing. This would just clarify them not looking. Doing the sampling in a different room/area where no one else can hear; not doing it in front of other people. Although we did not tell people if they were right or wrong, some samplers happened to be at the same place and over heard/saw the sampling being done by the other person. As mentioned before, our project went very smoothly, however, there are a few things we would do differently next time…
Modifications on Our Project Randomly generate which cup contains the Hershey’s chocolate for each sample. This would eliminate the chances someone reveals which cup contains Hershey’s if they knew. This would help to eliminate the bias created by drinking the cup of water in between because it would be effected by order. Changing the glass of water in between. After thinking it over, we realized the glass of water may not have been enough to remove/reduce the bias of having the taste in your mouth still. If we were to do this again, we would have them drink or possibly eat something proven to neutralize the taste buds. Conducting a double-blind experiment. This would eliminate all the “non-verbal” communications while conducting the experiment. We had four people sampling and modifying it by putting it to one who did not know the specifics would get rid of bias. Continued...
S A M P L E R S PI CTU RE S
Work Cited “Hershey Kisses Brand.” Hershey’s. The Hershey’s Company, n.d. 14 Dec. 2009. <www.hersheys.com>
