Why am I seeing highlighted search terms I didn't use in the Hub / EBSCOHost?
EBSCO is designed to support a wide range of searching - basic to expert.
This can have unintended consequences when the two styles of searching cross over
The below explanation relates to the Hub but also applies in EHost as the interfaces share the same underlying search engines.
If you search with "Find all my terms" and all the search expanders turned off for:
heart attack
Then EBSCO interfaces will do some basic term mapping in the background - the result will be the inclusion of more records as it will include myocardial infarction. The myocardial infarction search term hits will be highlighted as they are treated as part of your search.
If you search with the same settings in place for:
heart AND attack
You will only get records with heart AND attack somewhere in the searched fields - records that do not include those terms and instead use myocardial infarction will not be returned
Similarly a search for:
"heart attack"
Does not trigger the basic background term mapping - you would just get the two terms in order and directly next to each other.