I am using SPD 2007, Sharepoint 2007. I have a list that has a column of Yes/No choices. I need to calculate the number of times "Yes" is chosen. Is there a way that this can be done with calculated columns? And if so, what is the formula? Thank you.
The easy way: If all they need to do is see at a glance the number of Yes answers, just create a view on the list that groups items by that column. You'll get the count totals out of the box. You can then drop a list view web part that consumes that view anywhere you want on the site.
The hard way: If you go down the path of trying to store this value in a list, you are talking about a list item event receiver, which involves Visual Studio and farm code.
Unfortunate not with a Calculated column as they are calculated at the list item level plus they only get updated when the list item is being updated.
You could use a group list view and and aggregate count function. Alternatively look at something like the Data View Webpart.