Your reviewer is right about the last sentence. The obvious grammatical error is that it ought to be two sentences: you need to change the comma after 'detailed' into a full stop. Other grammatical issues: It's hard to tell whether the 'the' in the first line is correct. If youare listing other subcategories, it's fine. Otherwise, it should be 'a'. You don't allocate something into something. 'Allocate' basically means 'give', rather than 'put'. You could say, for example, 'allocating a separate subcategory to all such emotions' There are also a few vocabulary issues: The phrase 'beyond a guest's expectations' is confusing. 'Beyond' suggests better than they expected, but this doesn't fit the idea of disgust or boredom. Perhaps it should be 'outside the guest's expectations'. 'All mentioned emotions' is wrong. This is because the participle 'mentioned' cannot be used as an attributive adjective. The simplest solution is to say 'all such emotions' here. You could change 'Such emotions' on the previous line to 'These emotions' to avoid repetition. 'Detailed' doesn't quite express the right idea. An adjective such as 'unwieldy' might work. 'Compile' is not the right word. We compile something when we collect information from different sources and put it together to produce a document, list or book. Here's my suggested revision: Sentiment is a subcategory comprising the emotional reactions of a customer other than satisfaction, such as surprise, disgust, boredom. These emotions usually occur when something falls outside a guest’s expectations. My data suggests that allocating separate subcategories to all such emotions would make the taxonomy unwieldy. They were therefore grouped into a single subcategory.

As Jeff suggested, it seems your Reviewer wants a different style. Welcome to the ugly world of reviewing. :) Sentiment is the subcategory comprising emotional reactions of a customer other than satisfaction, such as surprise, disgust, boredom. Such emotions usually occur when something is beyond a guest’s expectations. My data suggests that allocating all the mentioned emotions into separate subcategories would make the taxonomy too detailed, therefore they were compiled into one subcategory. I changed "suggest" into "suggests" my data suggests, as data is usually collective. I changed "all mentioned" into "all the mentioned" If this seems relatively minor to you, I would agree with you. Allocating into is a little unusual You could go with My data suggests that allocating all the mentioned emotions to separate subcategories Again minor. compiled into one subcategory. --> compiled into a single subcategory. You have the skill to shuffle this yourself. I think what you have to decide is whether the reviewer will remember what they read and saw: that is do you need to change anything? Or perhaps completely reword the last sentence. All the mentioned emotions were allocated to a single subcategory as data suggested the taxonomy would become too detailed if they each had (formed?) their own (subcategory).

Hi Liza, I haven't corrected (it wasn't necessary) but I changed a lot of sentences to show you another way you could write this paragraph. Alternatively, if you only want to change the last sentence, I suggest breaking it into two as I have done. I hope this helps! Michelle https://www.italki.com/michelle Sentiment is the subcategory comprising the emotional reactions of a customer other than satisfaction. For example, surprise, disgust, or boredom. Such emotions usually occur when a customer's expectations are not met. My data suggests that allocating these emotions into separate subcategories would become too cumbersome. Therefore, they were compiled into the one subcategory. Cumbersome = awkward/unwieldy/unmanageable

Allocate all red cars to the left lane. Allocate all scratched cars to the left lane. Allocate all answered questions to the archive pile. ... that allocating all answered questions to the archive ... ... that allocating all mentioned emotions into .... Whatever the rule quoted, this does not seem incorrect to me. Well, you learn something every day. :)

Jeff, thanks a lot for your kind words, but my reviewer asked me to revise it because the last sentence is "not well constructed".