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Hello,
I analyse texts with Text Mining in SAS EM and already did a decision tree plus a logistic regression.
As a result I am getting e.g. an average square error (ASE). Can this indicator sufficently accept a hypothesis?
Or are there better indicators?
Thanks, in advance and hope you have an idea.
Kind regards,
Benjamin
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H Benjamin,
ASE is an estimate of model's mean squared error and it is not directly used for hypothesis testing. For example, in predictive modeling, you can use your model’s ASE on training and validation data to get an indication of overfitting. If your goal is overall hypothesis testing (between the target and all of the input variables), then you need to look at the overall p-value in the ANOVA table (available as on output of the Regression node). Total variance explained by the model and the model’s ASE (also degrees of freedoms of the model) are used together to calculate this p-value.
Hope this helps!
Funda
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Hi Benjamin,
More context please.
What does your Text Mining flow look like? And what are you trying to predict?
A general walk-through of your data and your goal would be nice too!
Thanks,
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Hi Migual,
The Text Mining flow contains nothing special. In detail it contains Text Parsing-, Text Filter-, Text Topic-,Text Cluster-, Data Partition-, Decision Tree- and Regression-Node. I try to determine, if the text topics (independent var.) can explain a metrical targer variable (e.g. company size). A null hypothesis could be: There is no correlation between the text topics and the company size.
Hope this make things clearer.
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H Benjamin,
ASE is an estimate of model's mean squared error and it is not directly used for hypothesis testing. For example, in predictive modeling, you can use your model’s ASE on training and validation data to get an indication of overfitting. If your goal is overall hypothesis testing (between the target and all of the input variables), then you need to look at the overall p-value in the ANOVA table (available as on output of the Regression node). Total variance explained by the model and the model’s ASE (also degrees of freedoms of the model) are used together to calculate this p-value.
Hope this helps!
Funda
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Hi Funda,
This sounds very good to me, the p-value is what I have been seeking for. I will try this.
Thank you.
Kind regards,
Benjamin
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Hi,
I tried this at SAS EM, but unfortunately I couldn't find the mentioned ANOVA table (with the p-value) of the Regresssion node.
Where can I find this table?
Best regards,
Benjamin
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ANOVA (Analysis of Variance) table is avalibale as an output of the regression node. P-value is shown by the pink arrow
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OK, I was in the wrong node (decision tree) 😉 Now I've found it.
Thank's again.