Editing Final Report/Thesis 2016 (section)

==== Main Test ====

The previous section has proved that the Levenshtein Distance actually can reveal the differences between languages. Based on this, the test in this section is to find out the difference between the mysterious code and texts of varies language.     
In the experimental group (line plots in figures), two versions the mysterious code were compared with 100 units of different languages extracted from the War and Peace. As the code is only of 50 letters long, there is no need to carry out the test in different unit length. 
In the comparison group (box plots in figures), units extracted from the UDHR were compared with the same materials in the experimental group. Like the preparation test, this test was also divided into 6 different length groups. 100 times of comparison was made, the 10 vs 10 double for loop structure was also preserved here. 
The reason why Latin language was not tested is because that the Latin version of the War and Peace was not found, and lacking of material for the control group test would affect the confidence.
Results are presented in the following figures. The horizontal line indicates the mean (average value) of the experimental group’s result and the boxes indicate results of the comparison group. For example, in the first plot: the six boxes represent the test result of UDHR units in English versus War and Peace units in English in six different length groups. Two lines indicate the test result of two versions of code versus units of War and Peace in English. The “Codes vs English” test results (red and green lines) appear in every plot as a reference.
[[File:Group2.jpg|thumb|600px|center|Levenshtein Main Test Result]]
The following interesting phenomenon could be observed from the Figure group2 above:

1. Observing within each plot: both the median value and the standard deviation fall as the unit length increases. This trend fits reasonably well with the trend of the preparation test (the one mentioned in the 2nd conclusion of section 4.1.2).
2.  Observing from the second plot to the last plot: there are distinct gaps between the Levenshtein Distances of codes versus English text (red and green lines), and the Levenshtein Distances of codes versus other languages (blue and purple lines).
3. Among all the languages tested except English and Turkish tests, results of the experimental group are consistently higher than results of the comparison group. In addition, experimental group’s result in Turkish was significant higher the one in English. 
4. Observing inside of the English test plot and the Turkish test plot: both the two groups of lines located around the median value of test result in 50 letters length group.
Conclusion:

According to the aforementioned phenomenon, the corresponding inferences can be drawn out:
1. The similarity of two trends reveals that the Levenshtein Distance algorithm does not sensitive to different testing materials. On the other hand, the relatively higher standard deviation in 50 letters group implies the higher randomness in small length tests. Notice that results of the experimental group are literally of 50-letters group. This reduces the credibility of the whole test.  
2. Within the scope of the experimental group, the mysterious code has relatively smaller Levenshtein Distance with English text compared to those with other languages.
3. The differences between results of experimental and comparison groups in six languages (German, Italian, French, Portuguese, Spanish and Polish) imply that the code is unlikely to be one of these languages.
4. In English and Turkish test results, the overlapped results from experimental and comparison groups imply the consistencies of the Levenshtein Distances between ‘Code vs War and Peace’ and ‘UDHR vs War and Peace’.