Sensory Discrimination Essay Example | Topics and Well Written Essays - 4000 words

Sensory Discrimination - Essay Example e has no sensory discrimination H1; Steve has sensory discrimination Method In this experiment, we utilize simple counts such as how many pieces of pizza were classified by the subject. The results were summarized in a 2 by 2 contingency table as shown below. The four numbers are a, b, c, and d, which are entered in the cells of the table according to the four categories. The total number of pieces of pizza which the subject can classify as Dominos Meatzza Feast or Pizza Hut Meat Lover’s pizza is: n= a + b + c + d From the table below we see that a total of a + c pieces of pizza were guessed correctly while b + d pieces of pizza were guessed incorrectly. If the subject cannot distinguish between Dominos Meatzza Feast and Pizza Hut Meat Lover’s pizza then a and c should be small. Conversely, if the subject can tell the difference between the two pizzas, we expect a and c to be about the same. (Weaver, 2008) Â   Guessed correctly Guessed incorrectly Total Dominos Meatzza Feast a b a + b Pizza Hut Meat Lover’s pizza c d c + d Totals a + c b + d a + b + c + d (=n) According to Fisher the probability of obtaining the values base above is given by the hyper geometric distribution below: (Deborah, 2000) The p-value is calculated in such a way that the margins of the table are fixed and, therefore, the respondant will give guesses with correct numbers in each category of the table. This leads to a null hypothesis of independence to a hyper geometric distribution of the entries in the cells of the contingency table. When using the chi square in the analysis, the approximation is not enough when sample sizes are small or if the data is very unequally distributed in the cells of the table. Therefore the cell counts have been predicted to be low. (Agresti, 2001) In this... The p-value is calculated in such a way that the margins of the table are fixed and, therefore, the respondent will give guesses with correct numbers in each category of the table. This leads to a null hypothesis of independence to a hypergeometric distribution of the entries in the cells of the contingency table. When using the chi-square in the analysis, the approximation is not enough when sample sizes are small or if the data is very unequally distributed in the cells of the table. Therefore the cell counts have been predicted to be low.18 pieces of pizza were prepared--9 pieces of Dominos Meatzza Feast and 9 pieces of Pizza Hut Meat Lover’s pizza. The pieces of pizza were presented to the respondent in a random order. The respondent’s task is to identify the 9 pieces of Dominos Meatzza Feast and the 9 pieces of Pizza Hut Meat Lover’s pizza, and he is informed of the design.ParticipantsThe participant in this study was Steve David. He claims to be able to tel l the difference between Dominos Meatzza Feast and Pizza Hut Meat Lover’s pizza since he runs a pizza store, and thus qualifies as an expert on the subject.The Fisher test is used with respect to the contingency table results. In this case, the test assesses what the expected frequencies will be if the null hypothesis is true. If there is no difference between Dominos Meatzza Feast and Pizza Hut Meat Lover’s pizza guesses, one would expect that Dominos Meatzza Feast would have been guessed correctly six times.