The fact that tap water was not well received is emphasized by the fact that 64.5 percent of the participants gave it the lowest score, or one of the lowest scores. If a participant gave two or more scores that were all the lowest, and tap water received one of these scores, then he is part of that 64.5 percent. However, if a participant gave all the bottles the same score, then he is not included in tat 64.5 percent seeing as he realized the bottles contained the same water. After obtaining a confidence interval, it can be established that there is a 95 percent chance that the true population proportion of nine to 17 years old students who would give the tap water the lowest score is between 0.477 and 0.814. This shows that the majority of the population to whom the results can be generalized would also give the tap water the lowest grade.
Of the 31 participants, only two realized that the waters were the same and were not supposed to taste different. This indicates that 93.5 percent of the participants gave at least two different grades. This also means that 93.5 percent of the participants tasted a difference. After calculating a confidence interval, it can be established that there is a 95 percent chance the true population proportion that is relevant and that would give different grades is between 0.849 and 1. Thus, the vast majority of the population would give different grades.
There was an interesting observation made. 10 of the 31 participants were females, meaning that 32.3 percent of the participants were females and 67.7 percent of the participants were males. The number of females that gave different grades is 10 and for the males, it is 19. This does provide enough evidence to suggest that females are more likely to give different grades and therefore taste a difference between the waters. However, the number of women that gave the lowest grade to tap water is nine. This seemed significant when compared to the fact that only 11 of the males gave the lowest grade to tap water. This meant that of the participants that gave tap water the lowest grade, 45 percent were females and 55 percent were males. It seemed that women are more likely to give tap water the lowest grade. However, after a hypothesis test was conducted to examine this claim, it was ultimately concluded that the results were not statistically significant. With a p-value of 0.18, it meant that it is likely women are not prone to giving the tap water the lowest grade.
Graphs
Conclusion
The results supported both parts of my hypothesis. It was concluded through the results that the vast majority (93.5 %) of the participants tasted a difference in the waters, showing that they were susceptible to the placebo effect. It was also concluded through the results and a hypothesis test that the participants gave the tap water a significantly lower grade. Since confidence intervals were calculated, these results could be generalized to the population of nine to 17 years old students.
As mentioned earlier, the purpose of this study was not to refute or approve of any of the theories regarding why and how placebo responses are generated. However, it was unlikely, at least in this case that the placebo responses were generated by the participants' motivation to cooperate with the experimenter. The participants did not know whether giving a high or low grade would help the experimenter.
A few conclusions could be drawn about human nature and behavior, the most obvious of which is that humans are very susceptible to the placebo effect. This study also provides evidence to why people think bottled water tastes better. Although a lot may genuinely think that bottled water tastes better, much of the reason why they think so may well be in the mind. Some participants of this study gave very high scores to certain brands of bottled water, even though what they were essentially drinking was tap water in a fancy bottle. Some participants later stated that they felt the Poland Springs water tasted truly like Poland Springs water.
This study's demonstration of the power of the placebo may also shed light as to why some people truly believe and claim alternative forms of medicine are effective, even when they have been scientifically proven to be ineffective. Today's world is filled with famous alternative forms of medicine and treatment, all of which have been debunked over and over by scientists. There are magnet therapists who claim that pain is caused by the iron in the blood, exorcists who claim it is caused by being possessed by a devil, and chiropractors who claim it is due to the back bone, even if the pain nowhere near the backbone. Even though such theories truly make no sense and are not supported by any empirical scientific evidence, practitioners of these theories still manage to gather a large number of believers. One logical and scientifically supported explanation for this popularity is because of the placebo effect. If these patients truly believe that they are being treated with the right medicine, they will feel better. After all, pain, depression, and so many different illnesses are all in the mind. Over time, such illnesses may naturally go away, but the patients will attribute the disappearance of symptoms to the alternative medicines. This increases their confidence in these alternative medicines, and the profit of the false doctors (Butler 74-95).
If this study was to be repeated again, it would be in the form of an experiment. There would be a control group who would actually be told to drink the real water and not tap water in different bottles. Then, there would be a treatment group that would drink the fancy tap water. In such a case, a cause-and-effect relationship could be established. Even though placebos usually serve as the control group, the purpose of this experiment would be to measure the effect of the placebo, not the effect of the actual bottles of water.
Furthermore, there would be more subjects so that the results can be more effectively generalized. It would be good if the subjects could be selected from a simple random sample despite how unreasonable that is because then, the results could be better generalized. There was also a confounding variable: it was not known whether or not the participants experienced the placebo effect as a result of hearing what the experimenter said and expecting to taste what the experimenter said or expecting the taste that they had always received from past experience, or even both. Such confounding variables would be eliminated next time by either saying nothing and having the participants drink out of those familiar bottles or by presenting the participants with brands they had never heard of and then suggesting the taste of the brands through words. A last major bias in this study was that even though the participants were told not to talk to each other, their facial expressions were still visible for the other participants to see. Such facial expressions associated with a good or bad taste may influence the decisions of the fellow participants. It would be much wiser to test each subject separately and alone.
