--This will show where only one table has the person (as comparing exact match on first and last name)

select	min([srcTable]) as srcTable
	,[last]
	,[first]
	,min(title) as title
from	(
	select 'roster' as [srcTable], [last], [first], title from roster
	union all
	select 'employees' as [srcTable], [last], [first], title from employees
	) d
group by [last]
	,[first]
having count(*) = 1 --limit restuls to where only one row exists from both tables


--This shows where the person exists in both table with different titles
select	e.[last]
	e.[first]
	e.title as emloyee_Title
	r.title as roster_Title
from	employees e
inner join roster r 
	on r.[last] = e.[last]
	and r.[first] = e.[first]
where	isNull(r.title,'no Title') != isNull(e.title, 'no Title')