On the All Comments screen, several filters are available that make it much easier to deal with the large volume of comments you'll receive.
One of those filters is for Tags that you can add to Comments. Tags allow you to group Comments in a way that makes sense.
Adding a tag is easy. Simply click on the Add Tag button or the little blue plus sign. This creates a block in which you can type a new tag. As you type, previous tags that you've used will be shown. Once done, hit enter or click the little green check sign. The new tag will be added immediately.
Now that you've added some tags, you can easily filter the comments by them. Enter the Tag you'd like to filter in the Search Tags box and click Apply. You'll notice that tags you've already created are once again presented to you as you type.
Tags are an excellent tool for organising comments in a way that makes sense to you. This will make it much easier to deal with the large volume of comments you'll collect as you send out more surveys.