Page 243 - qrps

© 2014 Pacific Crest 243
Technique Search
Category Ease of Use
Reduction ➌
Description Slicing a set of data from a larger data set based upon a search criteria
 Benefits  Limitations
Select the data of interest and filter out data not part
of the analysis
There is often information in the observations not
selected that may influence understanding the
information in the searched data
Tool Normally a search function
Application Narrowing the focus on a specific population
Example Search(Table,”age”, 15<age<25)
Technique Select
Category Ease of Use
Reduction ➋
Description Slicing a set of data from a larger data set based upon some rule -such as every 10th
row
 Benefits  Limitations
Often it is easier to work on a smaller set of data to
get a feel for the data before working on the whole
data set
The analysis may be biased based upon the sample
and needs careful validation with the complete data
Tool Select Function
Application Reduction of the data to a fraction of the original data to build a model before testing
with the rest of the data
Example Select(Table, .1) 1 of every 10 rows is selected
Technique Sort
Category Ease of Use
Rearrangement ➊
Description Changes the order of the data base using the sort type chosen for a specific attribute
 Benefits  Limitations
Allows study of sequencing patterns Blank values are separated; lose original order of
entry
Tool Normally a sort function
Application Determining the median, time series, clustering groups
Example Sort(Table,”age”) Will sort the set of people from lowest to
highest in age
5.4 Transforming Data