David Pham Tran
Biology 10H
Block 1
DRAFT OF RESULTS AND CONCLUSIONS

RESULTS

The purpose of this experiment was to test the colony counts of bacteria after growing them in the same amount of time. The independent variables of this project were the different locations in school that bacteria were being collected from. The locations were the doorknob at the staircase, the doorknob in the biology room, the bathroom sink, the bathroom toilet, the cafeteria table, the cafeteria railing, the water fountain, the locker combination, the floor of the biology room, and the hallway floor. The dependent variable was the number of colonies that grew from the bacteria. The control group is was the cafeteria table since it was constantly wiped. Quantitative data was used in this experiment and the level of data was ordinal. The ANOVA test was used to do the statistical analysis of the data. The means for the bacteria colonies of each location were respectively as follows: 32.6 for the staircase doorknob, 32.2 for the biology room doorknob, 44.2 for the bathroom sink, 32.2 for the bathroom toilet, 28 for the cafeteria table, 15 for the railing in the cafeteria, 30.6 for the water fountain, 21.8 for the locker combination, 24 for the biology room floor, 15.8 for the hallway floor. The null hypothesis was if the different locations in school have no effect on the colony counts of the bacteria, then the averages of colonies will be slightly the same. The p-value of this experiment was >0.05, approximately 0.033. Due to the p-value the null hypothesis was rejected. The alternative hypothesis was if bacteria are collected from different locations in school, then the colony counts of bacteria will be the same. The results of this experiment did not support the alternative hypothesis. As shown below in Table 1: The Counts Of Colony Depend On The Locations In School, the standard variations were the following: 7.89 for the staircase doorknob, 11.5 for the biology room doorknob, 26.8 for the bathroom sink, 10.0 for the cafeteria table, 12.2 for the bathroom toilet, 8.63 for the cafeteria railing, 13.9 for the water fountain, 8.41 for the locker combination, 14.0 for the biology room floor, and 9.68 for the hallway floor. As shown in Graph 1: The Average Counts of Colony, the average counts of colony were shown as following: 32.6 for staircase doorknob, 32.2 for biology room doorknob, 44.2 for bathroom sink, 28 for cafeteria table, 32.2 bathroom toilet, 15 for cafeteria railing, 30.6 for water fountain, 20.8 for locker combination, 24 for biology room floor, 15.8 for hallway floor.

TABLE 1: THE COUNTS OF COLONY DEPEND ON THE LOCATIONS IN SCHOOL

Descriptive Information
Staircase doorknob
Biology room doorknob
Bathroom sink
Cafeteria table
Bathroom toilet
Mean

Standard Deviation

Number
32.6

7.89

5
32.2

11.5

5
44.2

26.8

5
28.0

10.0

5
32.2

12.2

5

*Continue of the previous table due to lack of space
Descriptive Information
Cafeteria railing
Water fountain
Locker combination
Biology room floor
Hallway floor
Mean

Standard Deviation

Number
15.0

8.63

5
30.6

13.9

5
20.8

8.41

5
24.0

14.0

5
15.8

9.68

5

Results of ANOVA
*(This include both of the previous tables)
Between groups

F= 2.319
p>0.01 (0.033)
df= 49

CONCLUSIONS

The purpose of this experiment was to test the colony counts of bacteria after growing them in the same amount of time. The alternative hypothesis that the colony counts of the bacteria would be slightly the same even though they were collected from different locations was rejected. The reason why the results did not support the alternative hypothesis was because the colony counts of the bacteria turned out to be very different. The highest number of colony found in one petri dish was 84 and the lowest was 6. Only 3 out of 10 group average were in the range of 30 to 35 and only one group average was higher than 40. These results above were not enough to support the alternative hypothesis. To support the alternative hypothesis 7 out of 10 groups had to have the average in the same range. The independent variable (the different locations that bacteria were collected from) had this effect on the dependent variable (colonies) was because it depended on how dirty the locations were. If one location was extremely dirty like the bathroom sink or toilet, the more bacteria will be collected and the more colonies will grow. According to the literature review, bacteria would need at least 24 hours to be visible. The bacteria were ensured to be visible and develop as many colonies by leaving