Q:

Calculate unique rows based on conditional count

From the table below, I want to calculate the number of occurrences of score 0.0000 when the status is not 3. In addition, I want to return unique rows by question ID. 
I've tried COUNT and Group by clauses, but I couldn't get very far. Any help in the right direction would be greatly appreciated.
question_id question_desc   status  class_id    score
650               DE           3    1          0.0000
650               DE           2    1          1.0000
651             ADELA          2    1          1.0000
651             ADELA          2    1          1.0000
652               AE           2    1          1.0000
652               AE           2    1          1.0000
653               AP           2    1          0.0000
653               AP           2    1          1.0000

...transformed to... 
question_id question_desc   count 
650               DE           0
651             ADELA          0
652               AE           0
653               AP           1

A:

You can use case to count only rows that meet a condition:
select  question_id
,       question_desc
,       count(case when score = 0 and status <> 3 then 1 end) as [count]
from    YourTable
group by
        question_id
,       question_desc

That's assuming score is an exact numeric type, like decimal.  If it's an approximate numeric type, like float or real, use:
,       count(case when abs(score) < 0.00005 and status <> 3 then 1 end) as [count]

