I've included some screenshots below. Some posts will display different titles depending on what was searched. I don't know which title tag Google is using to give the page an SEO grade.
The page has this title:
"LSAT 69, Reading Comprehension, Passage 1, Small Farms"
That's too wide to display in the snippet. So, if there are no keywords, Google displays a shorter title, that looks like it was generated by Yoast, because it includes my sitename
With no keywords entered: https://www.dropbox.com/s/dfsezsxy4r7bov2/Title%20was%20too%20long.png
With keywords, part of the longer title is displayed:
https://www.dropbox.com/s/2htelbx7v4eeopd/Title%20with%20Keywords.png
Going forward, I'm just going to use shorter titles. But, do you have any insight into what's going on here, and do you know which title Google would use for SEO purposes?