There are at least two way to interpret missing values:
unknown / unobserved
known / missing
We currently assume missing values fall into the later case, but it might be nice to have the ability to say you know there is an attribute there, but it's value is unobservable, such as a masked value.
There are at least two way to interpret missing values:
We currently assume missing values fall into the later case, but it might be nice to have the ability to say you know there is an attribute there, but it's value is unobservable, such as a masked value.
Might be nice to add the ability to handle this.