Keyword error creating smart collection in LrC

"I created a smart filter for the first shoot, MATCH ALL, KEYWORDS, CONTAINS ALL, 2019 03 CORNWALL (PENZANCE). However, it returns all photos from both shoots (606 images in total), ie the smart filter is picking up images from both shoots.

Meanwhile if I create a filter for the second shoot MATCH ALL, KEYWORDS, CONTAINS ALL, 2019 09 CORNWALL (PENZANCE) it correctly returns just the 178 images from this shoot."

LR's text-matching operators were poorly designed, especially with respect to keywords containing spaces.

The criterion "Keywords contains all x1 x2 ... xn" matches a photo if, for each "xi", there is a keyword directly or indirectly assigned to the photo that contains "xi" somewhere in its name.

In your example, perhaps the photos assigned the keyword "2019 09 CORNWALL (PENZANCE)" were also assigned "94032".  So the criterion "Keywords contains all 2019 03 CORNWALL (PENZANCE)" matches because each of the strings "2019", "03", "CORNWALL", and "(PENZANCE)" is contained in at least one of the keywords assigned to the photos. 

Note that the Keywords criteria examine both keywords directly assigned to the photo and the hierarchical ancestors of those directly assigned keywords.  E.g. "contains all 03" would match the hierarchical keyword "94032 > Newtown".

If you don't think this explains what you're observing, the most efficient way to figure out the explanation would be:

1. In Library, select several of the photos that are assigned "2019 09 CORNWALL (PENZANCE)".

2. Do File > Export As Catalog, selecting just the option Export Selected Photos Only. The actual photos won't be included in the exported catalog, but that's fine.

3. Zip up the exported catalog folder and upload the .zip to Wetransfer, Dropbox, Google Drive or similar free service and post the sharing link here.

* * *

There are various ways to handle LR's design bugs with keyword matching:

1. Don't use spaces in your keywords. E.g. use "2019_09_CORNWALL_(PENZANCE)".

2. Use the Keyword List and Metadata browser to match exact keywords, as described in the link dj_paige posted above.

3. Use the Any Filter plugin, which has operators for matching text exactly.

Note that a previous workaround, using:

Match all of the following rules:
    Keywords starts with x
    Keywords ends with x

broke in LR 13.3:

https://community.adobe.com/t5/lightroom-classic-bugs/p-starts-with-text-filter-on-captions-or-filename-incorrectly-matches-words/idi-p/14729614

Smart Collection rules do sometimes have problems with multi-word keyword searching. Better is to simply select the keywords you want in the Keyword List panel, then the problem goes away. https://helpx.adobe.com/lightroom-classic/help/finding-photos-catalog.html

May I also suggest strongly that dates do not belong in keywords. The metadata containing dates is already in the original photo files, and LrC can work with those. If you had only keyword Cornwall (Penzance), you can still filter by date elsewhere in the Smart Collection definition or in the filter bar.

May I also suggest that a better hierarchy is to put the State above the City, such as, so if you want all Cornwall photos, those are easy to obtain from the Cornwall keyword, and if you want only the Penzance photos, you can find them easily using the Penzance keyword. In fact, keywords work better if they refer to a single piece of information, such as the city, rather than multiple pieces of information like you have with city state and date.

Cornwall

        Penzance

My hierarchy looks like this:

Hi @BPH8! Welcome to the community!

I tested this out on my end by creating two different smart collections using the same keywords you mentioned: 2019 03 CORNWALL (PENZANCE) and 2019 09 CORNWALL (PENZANCE). For me, they returned the correct photos as expected.

Perhaps one of the keywords got accidentally moved underneath the other in the hierarchy. You can check this by typing the keywords into the Keyword List search box and seeing if it has any child keywords.

Another possibility is that a keyword somehow got added as a synonym for the other. In the Keyword List panel, double-click each of the keywords in turn to see if one of them has any synonyms.
Hope this helps! 😊

Alek