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Why we use multiple threshold instead of single threshold
Posted by:
Hamideh62
Date: July 30, 2019 03:52PM
Hi,I work on high utility itemset mining and reads an article that uses multiple threshold instead of single threshold . I dont know why we do this . What is the benefit of define multiple thresholds?
Re: Why we use multiple threshold instead of single threshold
Posted by:
sadeq
Date: July 31, 2019 02:22AM
HI,
This is because items have different nature in a given dataset. some items appear frequently whereas others appear rarely. mining with a proper single support threshold is hard since, with high support threshold, the interesting rare ones will be missed while mining with a small support threshold generates a huge amount of itemsets that makes them expensive to be analyzed.
To overcome this issue, assigning multiple support to reflect the nature of each item in the dataset. So, those itemsets with small support can be generated with a samll support threshold and those itemsets with high support can be generated with high support. in such case, we find both frequent and rare itemsets without generating a huge amount of itemsets. Also, interesting rare itemsets are generated.
Regards,
Sadeq
This is because items have different nature in a given dataset. some items appear frequently whereas others appear rarely. mining with a proper single support threshold is hard since, with high support threshold, the interesting rare ones will be missed while mining with a small support threshold generates a huge amount of itemsets that makes them expensive to be analyzed.
To overcome this issue, assigning multiple support to reflect the nature of each item in the dataset. So, those itemsets with small support can be generated with a samll support threshold and those itemsets with high support can be generated with high support. in such case, we find both frequent and rare itemsets without generating a huge amount of itemsets. Also, interesting rare itemsets are generated.
Regards,
Sadeq