usability - Checkboxes - Is better to check exceptions or to uncheck exceptions?

I have a grid of ~20 checkboxes which users can utilize to select features. Typically, user might have ~15 features selected ~5 unselected for a co configuration.

Deselection of features which a user doesn't have is important for the overall use of application, because removing unnecessary features makes the application easier to use.

As a default configuration if a user doesn't change this setting the app behaves as if the user has all of the features.

Which of these scenarios is better?

Scenario A

• The question is positive.


• All checkboxes are checked as default.


• If user doesn't have some feature he unchecks the checkbox.

Example A - Default state

Which of these features do you have?
[✔️] A [✔️] B [✔️] C [✔️] D [✔️] E

[✔️] F [✔️] G [✔️] H [✔️] I [✔️] J
[✔️] K [✔️] L [✔️] M [✔️] N [✔️] O
[✔️] P [✔️] Q [✔️] R [✔️] S [✔️] T

Example A - User has changed these settings

Which of these features do you have?
[✔️] A [ ] B [✔️] C [✔️] D [✔️] E
[ ] F [✔️] G [✔️] H [✔️] I [✔️] J
[✔️] K [✔️] L [ ] M [✔️] N [ ] O
[ ] P [✔️] Q [✔️] R [✔️] S [✔️] T

Scenario B

• The question is negative.


• All checkboxes are unchecked as default.


• If user doesn't have some feature he checks the checkbox.

Example B - Default state

Which of these features don't you have?
[ ] A [ ] B [ ] C [ ] D [ ] E

[ ] F [ ] G [ ] H [ ] I [ ] J
[ ] K [ ] L [ ] M [ ] N [ ] O
[ ] P [ ] Q [ ] R [ ] S [ ] T

Example B - User has changed these settings

Which of these features don't you have?
[ ] A [✔️] B [ ] C [ ] D [ ] E
[✔️] F [ ] G [ ] H [ ] I [ ] J
[ ] K [ ] L [✔️] M [ ] N [✔️] O
[✔️] P [ ] Q [ ] R [ ] S [ ] T

Scenario C

• Anything else?

Important note

I can't ask the user for the features he has because if he changes nothing the application has to behave as though he has all of the features. This behaviour can't be changed because of business logic (the customer requires it and doesn't accept any argument).

Answer

Scenario C (This is Scenario B with a slight twist)

• 
  

  No questions: Turn on/off features is used instead.

  
  


• 
  

  All checkboxes are unchecked as default.

  
  
  
  
  • If there are mandatory features that the user can't turn off, they shouldn't be included.
  
  
  
  


• 
  
  

  If user doesn't have a feature he checks the checkbox.

  
  

Example C - Default state.

Turn on/off features:

[□] A [□] B [□] C [□] D [□] E  
[□] F [□] G [□] H [□] I [□] J   
[□] K [□] L [□] M [□] N [□] O  
[□] P [□] Q [□] R [□] S [□] T

Example C - User turns on the features they want.

Turn on/off features:

[□] A [□] B [□] C [□] D [□] E  
[■] F [■] G [□] H [■] I [□] J   
[□] K [□] L [■] M [□] N [■] O  
[■] P [■] Q [□] R [□] S [□] T

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I feel this is the least intrusive on the user and gives them the best user experience out of what was given. I wouldn't necessarily want all the features turned on. I'd rather turn on what I want, when I want.