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.
As suggested by the writer, amphibian species and their respective numbers have been on the decline in Xanadu National Park and trout as a predator is culpable for this trend. Logically speaking, the artificial introduction of trout to the park could have had a devasting impact on the numbers of amphibians as prey. This claim may be further corroborated by the decrease in amphibian species and numbers years later.
However, the link between introduction of trout in 1975 to the subsequent decrease in amphibian numbers cannot be determined by the truncated trend from 1975 to 2002 alone. Whether the decrease was a continued trend since before 1975 and showed accelerated rates or started drastically in 1975 after the introduction of trout may be a clearer indicator into the true impact of trout in the ecosystem.
Substantial declines in amphibian numbers worldwide may be a general trend which does not apply to those in Xanadu National Park, as suggested by the writer. To prove that similar reasons regarding global pollution of water and air did not impact the park’s amphibians, or that trout had a larger impact on amphibian populations in the park, the writer must first consider whether pollution also contributed to the decline. Relative measures of environmental health in the park such as water pH and mineral levels, may give us a more holistic picture on other factors in the park. Should tests indicate global pollution and water in Xanadu, which is highly likely, the writer would then do well to consider this impact in addition to that of trout.
Ecosystems like that of a pond in Xanadu National Park, while studied in isolation, have organistic relationships as complicated as that of their food webs. The writer should consider whether there were natural predators of amphibians before trout, or natural predators of trout which would have lessened their numbers in turn. The larger impact of trout being introduced to the ecosystem is much larger than the predator-prey relationship between trout and amphibian.
Comments
e-rater score report
Attribute Value Ideal
Final score: 4.0 out of 6
Category: Satisfactory Excellent
No. of Grammatical Errors: 5 2
No. of Spelling Errors: 6 2
No. of Sentences: 12 15
No. of Words: 333 350
No. of Characters: 1680 1500
No. of Different Words: 157 200
Fourth Root of Number of Words: 4.272 4.7
Average Word Length: 5.045 4.6
Word Length SD: 2.758 2.4
No. of Words greater than 5 chars: 125 100
No. of Words greater than 6 chars: 94 80
No. of Words greater than 7 chars: 66 40
No. of Words greater than 8 chars: 47 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 27.75 21.0
Sentence Length SD: 6.857 7.5
Use of Discourse Markers (%): 0.667 0.12
Sentence-Text Coherence: 0.43 0.35
Sentence-Para Coherence: 0.64 0.50
Sentence-Sentence Coherence: 0.148 0.07
Number of Paragraphs: 4 5
Transition Words or Phrases used:
also, but, first, however, if, may, regarding, so, then, well, while, in addition, such as
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 19.6327345309 56% => More to be verbs wanted.
Auxiliary verbs: 11.0 12.9520958084 85% => OK
Conjunction : 11.0 11.1786427146 98% => OK
Relative clauses : 8.0 13.6137724551 59% => More relative clauses wanted.
Pronoun: 13.0 28.8173652695 45% => OK
Preposition: 55.0 55.5748502994 99% => OK
Nominalization: 8.0 16.3942115768 49% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1723.0 2260.96107784 76% => OK
No of words: 333.0 441.139720559 75% => More content wanted.
Chars per words: 5.17417417417 5.12650576532 101% => OK
Fourth root words length: 4.27180144563 4.56307096286 94% => OK
Word Length SD: 2.79636827535 2.78398813304 100% => OK
Unique words: 162.0 204.123752495 79% => More unique words wanted.
Unique words percentage: 0.486486486486 0.468620217663 104% => OK
syllable_count: 524.7 705.55239521 74% => OK
avg_syllables_per_word: 1.6 1.59920159681 100% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 1.0 4.96107784431 20% => OK
Article: 6.0 8.76447105788 68% => OK
Subordination: 3.0 2.70958083832 111% => OK
Conjunction: 2.0 1.67365269461 119% => OK
Preposition: 1.0 4.22255489022 24% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 12.0 19.7664670659 61% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 27.0 22.8473053892 118% => OK
Sentence length SD: 40.7665269826 57.8364921388 70% => OK
Chars per sentence: 143.583333333 119.503703932 120% => OK
Words per sentence: 27.75 23.324526521 119% => OK
Discourse Markers: 7.5 5.70786347227 131% => OK
Paragraphs: 4.0 5.15768463074 78% => More paragraphs wanted.
Language errors: 0.0 5.25449101796 0% => OK
Sentences with positive sentiment : 5.0 8.20758483034 61% => OK
Sentences with negative sentiment : 2.0 6.88822355289 29% => More negative sentences wanted.
Sentences with neutral sentiment: 5.0 4.67664670659 107% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.201883658332 0.218282227539 92% => OK
Sentence topic coherence: 0.0921328913028 0.0743258471296 124% => OK
Sentence topic coherence SD: 0.0576746445599 0.0701772020484 82% => OK
Paragraph topic coherence: 0.136436114246 0.128457276422 106% => OK
Paragraph topic coherence SD: 0.0667667418042 0.0628817314937 106% => OK
Essay readability:
automated_readability_index: 16.8 14.3799401198 117% => OK
flesch_reading_ease: 44.07 48.3550499002 91% => OK
smog_index: 8.8 7.1628742515 123% => OK
flesch_kincaid_grade: 13.8 12.197005988 113% => OK
coleman_liau_index: 13.0 12.5979740519 103% => OK
dale_chall_readability_score: 8.77 8.32208582834 105% => OK
difficult_words: 80.0 98.500998004 81% => More difficult words wanted.
linsear_write_formula: 11.0 12.3882235529 89% => OK
gunning_fog: 12.8 11.1389221557 115% => OK
text_standard: 13.0 11.9071856287 109% => OK
What are above readability scores?
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Rates: 50.0 out of 100
Scores by essay e-grader: 3.0 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.