In previous version of JMP, a double click on a column header was enough to open the Column Info.
In JMP19 a double click can be used to edit the column name.
To get the old behavior back, one can go to Preferences / Tables and activate "Double Click Opens Column Info".

With this setting, an extra click is needed to edit the column name: The user has to select the column name manually in the 'Column Info'.
If the column name was selected immediately after opening the 'Column Info' window(*),
both features could be accessed simultaneously.
- double-click to open the Column Info
- double click to edit the column name
great: "OK" is still active after manually selecting the column name.
So, if you closed your eyes, you wouldn't notice the difference between this advanced Colum Info (*) and the JMP19-"edit column" via Double Click on the Header: Just double click, type the new name and press enter.
If you want to do more than just change the name, stay in the column info menu and make whatever changes you need.
What is your experience?
Have you wondered about the new behavior?
How often do you have to change the column name? How often do you change another setting?
-> Did you activate the legacy mode via the preferences?
What do you think about (*)?
In the future, the first 10 minutes in a JMP for Beginners Webinar:
->"Just Double click on the Column Header to open the Column Info".
<- "Teacher, this doesn't work on my computer."
<- "neither on mine"
<- "dito"
<- "it worked for ages! but the function seems to be gone"
<- "hey, on my computer it works"
?!?!
...
-> "Hm, let's start a survey - which setting should we use in our company".
<- 50/50
"If there was an option to get both functions at the same time"
How did we change a column name in JMP<= 18?
- select the column name in the Header - ... - write the new column name - Enter
[just works if no row is selected]
- click on the the column name in the column menu on the left - click again - write the new name - Enter (*)
- Double Click on the Column Header to open the column Info
write the new column name - wonder nothing happend - wonder why the column name is not selected - select the column name
- write the new column name again - press Enter.
(*) same behavior to change the name of a Table Scripts in JMP <=18: select the script - click again - write - Enter.
now in JMP19: double click
https://community.jmp.com/t5/Discussions/Undocumented-Secrets/m-p/908323/highlight/true#M106664