Page 241 - qrps

© 2014 Pacific Crest 241
Technique Lookup Table
Category Ease of Use
Modifying ➌
Description The replacement of values in an attribute with new values based upon conditional
rules
 Benefits  Limitations
Can be used for clustering data, recording, building
frequencies, and remapping
Data not fitting a rule will become missing values
Tool Lookup
Application Survey data, restructuring relationships, organizing relationships
Example Lookup(“cities”,”city/States”) Produce a state mapping
Technique Merge
Category Ease of Use
Combining ➍
Description Integrating the data from two data sets into a single data file
 Benefits  Limitations
Can relate two sets of data based upon the key
attribute that is being studied
The key attribute occurrence must be in each data file
or that value will be missing associated data
Tool Mapping function or Merging function
Application Comparison studies - like high school vs. college performance
Example Merge(“High School”, “College”,StudentID)
Technique Moving Avg
Category Ease of Use
New Attribute ➋
Description Find the average of a number of periods both before and after the current period
 Benefits  Limitations
Smoothing out trend data so the trend data can be
seen more clearly
There will be missing values at the beginning and end
of the data because of no data to average
Tool Moving avg or a combination of functional transformations and Lag variables
Application Time series analysis - Reducing variability to see patterns
Example Movingavg(“Price”, 5) will produce a 5 day moving average of
Price
5.4 Transforming Data