The term 'couch potato' may seem harmless, but television watching has

Could you please evaluate my essay from Princeton Review practice test 9? What puzzles me is that Princeton reviewer's grade was 3.5 and I have been receiving grades of 1-2 grade units lower from Princeton than I have from other platforms / essay graders, making it more difficult to gauge my actual AWA level.

Prompt:

"The term 'couch potato' may seem harmless, but television watching has been shown to shift mental activity from higher brain regions to lower ones. That is because TV is a one-way medium, reducing one's tendency to engage and interact. Using a computer, on the other hand, is a two-way activity that encourages interaction. Since many television watchers report feeling sluggish and even sleepy after several hours' viewing, it is clear that switching off the TV and switching on the computer will result in increased energy, brain activity, and mental sharpness."

Answer:

The author of the argument claims that using a computer instead of watching television will result to increased energy, brain activity and mental sharpness. In order to support this claim, the author mentions that television watching shifts mental activity to lower brain regions, that computers encourage more interaction than televisions do and that TV watchers report feelings of sluggishness and sleepiness after several hours of viewing. The argument, as it stands, is unsubstantiated, as it relies on assumptions which are not clearly supported by the evidence and whose truth is necessary in order to reach to that particular conclusion.

First of all, the author cites that television shifts mental activity from higher brain regions to lower ones. For one thing, he does not provide any study or evidence to validiate this claim. Most importantly, he does not cite any link between the location of the mental activity within the brain and the resulting levels of energy, mental sharpness or brain activity. On the contrary, he merely assummes that shifting mental activity in lower areas of the brain causes lower energy levels, mental sharpness and brain functioning, and vice versa. In order to better evaluate the usefulness of this evidence for the argument's conclusion, one would require a scientific correlation between the brain region of mental activity and the individuals' energy and brain activity levels in general.

Furthermore, just because the computer is a two-way medium, its users do not necessarily interact with it any more than they do with television. In particular, if the purpose of the individual is to watch a movie or a series, switching to a computer will result in minimal differences in the individual's level of engagement and, according to the author's line of reasoning, to the level of mental sharpness and activity.

Lastly, the author clearly implies that the level of engagement is crucial when it comes to energy and brain activity levels. While this thought might have some merit, extensive use of either a computer of a television can be almost equally exhausting mentally. Even if many television users feel sluggish or sleepy after several hours of viewing, that might aswell be the case for computer users. In order to strengthen his line of reasoning, the author should articulate the consequences of excessive hour of computer usage on the subsequent levels of energy, brain activity etc.

To summarize, the argument omits the aforementioned key several factors, on the basis of which it could better be evaluated. An established link between the region of mental activity and activity levels and the effects of excessive computer usage on the same levels comprise necessary information that the author should provide and the absence of which renders the argument unconvincing.