Another way to interact with people in your Google+ Professional Learning Community is to show your agreement or appreciation by adding a "+1" to a post or comment. Here is how Google describes a +1:
When you read a post that makes you want to cheer, +1 is your applause; when you watch a video that has you in stitches, +1 is your laughter; when you see a photo that perfectly captures that special moment, +1 is your 5-star review.
When you +1 a post on Google+, the creator of that post AND the people the post was shared with can see your +1. The creator of the post will receive a notification that you +1'd their post.
When you +1 a comment, the creator of that post, the people the post was shared AND the person who made the comment can see your +1. The creator of the comment will receive a notification that you +1'd their comment. So, a good rule of thumb is to only +1 posts, comments or photos when you’re comfortable with other users seeing your recommendation.
To +1 a post, just click the "+1" button below the post
You can tell that you have +1ed a post because the +1 button will be red and your Profile picture will be visible. To remove your +1, just click the red +1 button.
To +1 a specific comment, hover your mouse cursor above the comment and a small +1 button will appear. Click the small button to add your +1 to that comment
As +1s are added to comments and posts, the number on the +1 button increases by one. The more +1s, the higher the number displayed