This was posted a few days ago, so maybe this is too late of a feedback, but I just saw this so I'll give you some feedback anyway.
I'll start with the things that are easier to fix in your writing. First, you have to proofread. Little errors here and there are not going to affect your overall mark, but there are way too many grammatical and spelling errors here and this quality will surely negatively affect your score. The errors I point out and my edits are underlined for your reference.
Second, the essay is way too short. You need to develop each of your points more with counterexamples and stronger explanation. At the current stage, this essay would likely receive somewhere around 3-3.5 if the grader is generous.
An easy to way to fix this is by practicing essay structure. A simple formula to follow is:
Intro (where you re-state what the author argues and what evidences the author cites, and why those evidences are inadequate for his claim, and what kinds of evidence he might need to provide if he wants to make his argument more convincing)
[First,] then talk about one type of evidence he can provide to make his conclusion that one can only cross the Brim River with a boat. An example of a hypothetical evidence might be something like, maybe the Paleans did not have boats but they used other mechanisms to cross the river. Or maybe there was a trade route that went around the river by land, so that they didn't have to cross the river by boat. OR, you can also argue that the lack of presence of boats might be because those boats were destroyed years later. In that case, the author would have to show other corroborating evidence that concretizes the claim that the Paleans did not have access across the river by boats.
[Moreover,] maybe the Paleans in fact DIDN'T have boats, but maybe the people of Lithos did. In this case, you can expand on this by showing that, if the author can also provide evidence that, not only did the Paleans not have boats, but other villages also did not have access to Palea by boats, then the author's argument would be made stronger. That's another evidence the author can provide to make his case stronger.
[Finally,] and make another point here about the weakness of his evidences for his conclusion, and what kind of evidence he might need to make his argument stronger. Remember, the essay is about analyzing the evidence that the author provided for his argument. Your job is to show how the evidence he's provided either weakens or strengthens his case, and what kinds of evidence he might need to further provide in order to actually make his conclusion more convincing.
Then always end with a conclusion.
Now, about your response essay itself: Your conclusion doesn't seem very well connected to the previous points you were making. The points you've been making up until the conclusion were that, despite what the author says, the Paleans may have had ways of getting across the Brim River. It's a sudden shift in the conclusion to say that showing that these baskets existed in other societies outside of Palea and Lithos makes the author's argument stronger. You want to make sure your essay is consistent from beginning to end.
Also, you might want to reconsider that last conclusion because, if the baskets were found in other societies, it still doesn't negate the possibility that it is uniquely Palean. The fact that getting across the River to Lithos was a challenge for the Paleans doesn't mean that their connection with other villages also had the same challenges. Maybe Palea had easier access to another village than to Lithos. I would probably argue that, if the author was able to show that, aside from the lack of presence of boats, Palea was also a completely isolated village cut off from all other villages, then that would strengthen his argument.
So just as a quick summary:
1. Make sure you WRITE WRITE WRITE. You want to use up every single second of the test time and jampack as much detail and expansion of your points as possible. You can't just write one sentence or two sentences per point and move on to the next point. Each point you make should take up a paragraph on their own.
2. Keep your essay consistent from the intro to the conclusion. Your intro should state your main point, your 3 body paragraphs should each make a particular point that supports your intro argument, and then your conclusion should be a summary of the previous paragraphs. The conclusion should NOT be introducing some new element of thought into the essay. Also, as much as possible, the examples you use and the points you make should have some level of connection with preceding paragraphs and points. You want to build on previous thought.
Just as a reference, I got a 6 on the writing portion of the GRE. Here's a sample Analyze the Argument essay I wrote for the Princeton Review practice test, which gives you live grading on your essay. I got a 6 on this, so I think this should be somewhat helpful to your writing practice. The results don't show the prompt itself, so I'm just attaching the essay I submitted for your reference. Hope this helps!
You'll notice that my essay is SIGNIFICANTLY longer than yours. Length really matters. Even if you make a few grammatical mistakes and even if you might not feel too confident on the subject, as long as you fit in a lot of words to help make each point as detailed as possible, it goes a long way to helping you. The Princeton Review book (I think) actually talks about how one of the common features of 5.5+ essays is that they're all quite long.
The movie producer makes several assumptions that are not warranted and that require solid substantiation if his argument is to be convincing. First, the producer assumes that the amount of retakes done in commercials are wasteful. Second, even if one were to assume that the produce is correct about the wastefulness of the advertising industry, it is not then clear that the next step which the producer takes in assuming that this particular inexperienced director, due to his background in commercial advertisements, will definitely reflect the trend of the advertising industry's wastefulness is a warranted assumption. And third, the producer assumes that, due to the inexperience of the director, the quality of the film will be directly related to the amount of retakes that the director will undertake. All of these assumptions must be proven true in order for his argument to be convincing.
First, the producer may be missing some crucial information regarding why the advertising industry in particular takes multiple takes after multiple takes. Commercials are inherently short, not usually focused on the artistic expression through the medium of film, and instead focused on selling the product about which the commercial is made, not the commercial itself. As such, the approach to filming commercials may be inherently different to filming movies. It may be plausible that the reason why commercial directors require multiple takes is because the actors themselves are not as talented as A-list actors in movies. It is often the case that commercials hire unknown models and inexperienced and new actors, which may explain why there are multiple takes. In such a case, it may not be the problem of the director at all. Moreover, because the commercials are primarily focused on selling a product rather than artistic expression, it may be that the sales team, the marketing team, and the executive team of the company, may have much more say in the creation of the film, which means that a director will have much more to consider besides artistic creativity in making the commercials. The assumption that the high spending of the advertising industry will also directly translate into the movie making industry due to the director's advertisement background is without sufficient grounds and must be substantiated if it is to be taken seriously.Second, the producer assumes that a director whose background is in advertisements is also not able to adapt to the new context in which the director will be working. A sufficiently talented director may have no problem adjusting his approach and method in order to fit the context in which he is now in. For example, [took out the name for privacy, but if you can use real life examples, great!] Productions, a very recently founded production company, began with filming wedding videos and music videos before switching to advertisements, and the founder often speaks of the adjustments he has to make in order to accommodate the new purpose of the films. That is, a creative director, whether experienced or inexperienced, will often have the talent to adjust and switch his approach to filming based on what he is filming and for what purpose. The producer's argument seems to neglect the creativity and versatility of advertisement directors.Lastly, the producer assumes that inexperienced directors will require many takes before creating a quality final product. However, it is not at all clear that the two are directly related. For example, to use the hypothetical situation mentioned above, it may have very well been the case that the many retakes that the director had done in the past were due to feedback and direction of the executive, sales, and marketing teams for which he was working, rather than anything that the director thought was lacking when it comes to the film quality itself. In such a case, on the one hand, it was ultimately the executive/sales/marketing teams' decision to do takes multiple times rather than the choice of the director. On the other hand, even if it was the explicit choice of the director, it may very well have been the fact that the director has to keep in mind many other factors besides telling a compelling story through the medium of film that led to his multiple retakes. Often times, telling a story in a dramatic and highly descriptive and artistic manner does not always translate to the ability to sell a product. The producer has not considered that a director's ability in this new context to focus strictly on creating a compelling story through a medium of the movie may allow the director to be more focused and less reliant on multiple takes. As such, the producer, if his request for 10% increase in budget is to be convincing, must substantiate his assumptions by showing that the particular director has a history of wasteful scene retakes which are not the result of multiple factors outside his control, but rather the result of his own ineptitude.In conclusion, the producer makes too many unsubstantiated and unwarranted assumptions that are not fair to the director nor convincing to those he would be pitching his 10% increase request. These assumptions must be explicitly stated, then explained and substantiated with evidence before his request can be convincing enough for the studio to provide him with the extra funds.
Hope this is helpful and let me know if you have any questions!