The following is a letter to the editor of an environmental magazine.
"In 1975 a wildlife census found that there were seven species of amphibians in Xanadu National Park, with abundant numbers of each species. However, in 2002 only four species of amphibians were observed in the park, and the numbers of each species were drastically reduced. There has been a substantial decline in the numbers of amphibians worldwide, and global pollution of water and air is clearly implicated. The decline of amphibians in Xanadu National Park, however, almost certainly has a different cause: in 1975, trout — which are known to eat amphibian eggs — were introduced into the park."
Write a response in which you discuss what specific evidence is needed to evaluate the argument and explain how the evidence would weaken or strengthen the argument.
The author of the letter comes to a conclusion that trout is responsible for the decrease in the number of species as well as the decrease in the number of amphibians for the remaining species in Xanadu National Park. However, to correctly attribute this decrease to the introduction of trout in the national park in 1975, one would require the following pieces of evidence.
Firstly, what was the methodology that was used to count the number of amphibians in 1975? One would require to know the actual methodology that was used in 1975 to ascertain if the population of the amphibians in the national park was correctly recorded without any discrepancy. There is a possibility that the methods used in 1975 were not technically sophisticated and carried in them an innate fallacy. Thus, one was able to record more number of amphibians then they actauly were. Further, those naive methods might have identified seven different species when there were only four different species. If either of the case is true, then the author's conclusion that there is a decrease in the number of amphibians is significantly weakened.
Secondly, does the national park has the same number of ponds that it had in 1975? The author prematurely assumes that there has been no decrease in ponds in the national park while there is a decrease in the number of amphibians. However, that assumption might not be true. Perhaps, there has been a decrease in the number of ponds in the national and that could be the reason for the decrease in the amphibian population. Further, the area of the national park might have been reduced for economic development of the region and this lead to the removal of ponds that used to have amphibians in large number. If the above scenarios have any merit, the author's argument does not hold water.
Finally, does the trout that was introduced into the natioal park feed on the eggs of the species present in the national park? The author only mentions that the trout feeds on the eggs of the amphibians. However, the author's explanation seems to be ambigious as the author does not confirm if they feed on the eggs of the species present in the national park. There is a possibility that though the trout feeds on eggs of amphibians, it has antipathy towards eating the eggs of the species present in the national park. If that is the case, then the author's conclusion that the decrease in the population of amphibians is due to the trout is spurious.
Therefore, the argument, as it stands, is unwarranted as it does not provide further evidence that will help us to properly evaluate the conclusion. One will be in a better position to evaluate the argument if the author can provide further evidence, perhaps, in the form of a schematic study.
Comments
e-rater score report
Attribute Value Ideal
Final score: 3.5 out of 6
Category: Satisfactory Excellent
No. of Grammatical Errors: 1 2
No. of Spelling Errors: 4 2
No. of Sentences: 21 15
No. of Words: 477 350
No. of Characters: 2244 1500
No. of Different Words: 163 200
Fourth Root of Number of Words: 4.673 4.7
Average Word Length: 4.704 4.6
Word Length SD: 2.614 2.4
No. of Words greater than 5 chars: 151 100
No. of Words greater than 6 chars: 124 80
No. of Words greater than 7 chars: 87 40
No. of Words greater than 8 chars: 48 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 22.714 21.0
Sentence Length SD: 7.388 7.5
Use of Discourse Markers (%): 0.714 0.12
Sentence-Text Coherence: 0.386 0.35
Sentence-Para Coherence: 0.589 0.50
Sentence-Sentence Coherence: 0.155 0.07
Number of Paragraphs: 5 5
Grammar and spelling errors:
Line 3, column 110, Rule ID: ALLOW_TO[1]
Message: Did you mean 'knowing'? Or maybe you should add a pronoun? In active voice, 'require' + 'to' takes an object, usually a pronoun.
Suggestion: knowing
...f amphibians in 1975? One would require to know the actual methodology that was used in...
^^^^^^^
Line 3, column 647, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'authors'' or 'author's'?
Suggestion: authors'; author's
...If either of the case is true, then the authors conclusion that there is a decrease in ...
^^^^^^^
Line 5, column 34, Rule ID: DOES_NP_VBZ[1]
Message: Did you mean 'have'?
Suggestion: have
...ed. Secondly, does the national park has the same number of ponds that it had in...
^^^
Line 5, column 654, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'authors'' or 'author's'?
Suggestion: authors'; author's
...the above scenarios have any merit, the authors argument does not hold water. Finall...
^^^^^^^
Line 7, column 219, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'authors'' or 'author's'?
Suggestion: authors'; author's
...he eggs of the amphibians. However, the authors explanation seems to be ambigious as th...
^^^^^^^
Line 7, column 384, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...he national park. There is a possibility that though the trout feeds on eggs of a...
^^
Line 7, column 553, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'authors'' or 'author's'?
Suggestion: authors'; author's
...nal park. If that is the case, then the authors conclusion that the decrease in the pop...
^^^^^^^
Transition Words or Phrases used:
but, finally, first, firstly, however, if, second, secondly, so, then, therefore, thus, well, while, as well as
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 27.0 19.6327345309 138% => OK
Auxiliary verbs: 9.0 12.9520958084 69% => OK
Conjunction : 3.0 11.1786427146 27% => More conjunction wanted.
Relative clauses : 17.0 13.6137724551 125% => OK
Pronoun: 27.0 28.8173652695 94% => OK
Preposition: 68.0 55.5748502994 122% => OK
Nominalization: 14.0 16.3942115768 85% => OK
Performance on vocabulary words:
No of characters: 2299.0 2260.96107784 102% => OK
No of words: 477.0 441.139720559 108% => OK
Chars per words: 4.81970649895 5.12650576532 94% => OK
Fourth root words length: 4.67336384929 4.56307096286 102% => OK
Word Length SD: 2.68129828201 2.78398813304 96% => OK
Unique words: 172.0 204.123752495 84% => More unique words wanted.
Unique words percentage: 0.360587002096 0.468620217663 77% => More unique words wanted or less content wanted.
syllable_count: 716.4 705.55239521 102% => OK
avg_syllables_per_word: 1.5 1.59920159681 94% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 4.96107784431 60% => OK
Article: 7.0 8.76447105788 80% => OK
Subordination: 4.0 2.70958083832 148% => OK
Conjunction: 0.0 1.67365269461 0% => OK
Preposition: 2.0 4.22255489022 47% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 21.0 19.7664670659 106% => OK
Sentence length: 22.0 22.8473053892 96% => OK
Sentence length SD: 42.027741621 57.8364921388 73% => OK
Chars per sentence: 109.476190476 119.503703932 92% => OK
Words per sentence: 22.7142857143 23.324526521 97% => OK
Discourse Markers: 5.28571428571 5.70786347227 93% => OK
Paragraphs: 5.0 5.15768463074 97% => OK
Language errors: 7.0 5.25449101796 133% => OK
Sentences with positive sentiment : 10.0 8.20758483034 122% => OK
Sentences with negative sentiment : 4.0 6.88822355289 58% => More negative sentences wanted.
Sentences with neutral sentiment: 7.0 4.67664670659 150% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.280204467352 0.218282227539 128% => OK
Sentence topic coherence: 0.0904018941894 0.0743258471296 122% => OK
Sentence topic coherence SD: 0.06618965876 0.0701772020484 94% => OK
Paragraph topic coherence: 0.157977000069 0.128457276422 123% => OK
Paragraph topic coherence SD: 0.0942637282943 0.0628817314937 150% => OK
Essay readability:
automated_readability_index: 12.6 14.3799401198 88% => Automated_readability_index is low.
flesch_reading_ease: 57.61 48.3550499002 119% => OK
smog_index: 8.8 7.1628742515 123% => OK
flesch_kincaid_grade: 10.7 12.197005988 88% => OK
coleman_liau_index: 10.97 12.5979740519 87% => OK
dale_chall_readability_score: 7.41 8.32208582834 89% => OK
difficult_words: 81.0 98.500998004 82% => More difficult words wanted.
linsear_write_formula: 14.0 12.3882235529 113% => OK
gunning_fog: 10.8 11.1389221557 97% => OK
text_standard: 11.0 11.9071856287 92% => OK
What are above readability scores?
---------------------
Rates: 58.33 out of 100
Scores by essay e-grader: 3.5 Out of 6
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.