NO.PZ202304050200007103
问题如下：
After cleansingthe data, Steele then preprocesses the dataset. She creates two new variables:an “Age” variable based on the firm’s IPO date and an “Interest Coverage Ratio”variable equal to EBIT divided by interest expense. She also deletes the “IPODate” variable from the dataset.
During the preprocessing of the data in Exhibit 1,what type of data transformation did Steele perform during the datapreprocessing step?
选项：
A.
Extraction
B.
Conversion
C.
Aggregation
解释：
A is correct. During the data preprocessing step,Steele created a new “Age” variable based on the firm’s IPO date and thendeleted the “IPO Date” variable from the dataset. She also created a new“Interest Coverage Ratio” variable equal to EBIT divided by interest expense.Extraction refers to a data transformation where a new variable is extractedfrom a current variable for ease of analyzing and using for training an MLmodel, such as creating an age variable from a date variable or a ratiovariable. Steele also performed a selection transformation by deleting the IPODate variable, which refers to deleting the data columns that are not neededfor the project.
date conversion具体来说是做什么呢？和extraction怎么区分？