How should missing {type definitions] be interpreted?

My apologies up front if this question has been 
answered many times. I've tried searching what 
I can think of with no success. 

I've read the spec and understand that if no type
attribute is supplied and no simpleType or complexType
child is specified then both attribute declarations
and element declarations have a default type of 
simple-ur-type or ur-type (respectively). 

However, I'm still confused about how a parser should 
interpret a schema with declarations that have no
{type definition} specified. I've tried the mail 
archives and haven't been able to find anything that
clearly explains whether the parser should: 

* treat the element or attribute as not being allowed
	to contain any data or children

* treat the element or attribute as being allowed 
	to contain any data or children

The datatype spec seems to imply, at least for attributes, 
that if no type is specified then the default simple-ur-type
is a union of all the built-in primitive types and thus
it would be valid for the attribute to contain data that 
matches any of these. 

What is correct here? 

Sara Mitchell