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sql server data mining : Newbie question on EQUAL_AREAS and cases


Bob
9/20/2005 10:53:20 AM
I've created a view joining (in essence) customers with sales. I am
then trying to predict sales amount (continuous) by customer attribute
inputs. I selected DISCRETIZED(EQUAL_AREAS,4) for the predicted
variable (sales amount).

What I don't understand is what "value" is telling me in the model. I
can understand the number of cases associated with "node total" under
value, as well as the number of cases associated with "missing".
However, the other values are numbers like "832.125", with an
associated case total of 593. Now to get that case total, the sales
amount had to be between 175 and 1,490. So in short, what the heck are
the actual sales ranges associated with these "equal buckets".

Also, as to the definition of "case", I understand that in my example
the case is a "customer" with a key of customer_id. But in the data
mining model, the number associated with "cases" for the "all" category
is a distinct count of all the input variables and the predicted
variable. So even though I define the case to be customer_id, the data
mining output makes the case count much higher and equal to again, the
distinct count of all the variables in the model.

Thanks.

--Bob Harford
Data Warehousing Architect
AlphaInsight Corp. / Falls Church, VA
Raman Iyer [MS]
9/20/2005 12:35:39 PM
The value you see for discretized columns is the midpoint of the discretized
range. To get the actual range endpoints, you can use the RangeMin and
RangeMax functions:
SELECT DISTINT RangeMin([sales amount]), RangeMax([sales amount]) FROM
<YourModel>

Re. the case question:
If your mining model key column is customer_id, the number of cases should
be the same as the number of customers.
Can you provide your model creation statement? Are you using Analysis
Services 2000 or 2005?

--
-Raman Iyer
SQL Server Data Mining
[This posting is provided "AS IS" with no warranties, and confers no
rights.]

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