Page 240 - qrps

Quantitative Reasoning & Problem Solving
240 © 2014 Pacific Crest
Technique Functional Transformation
Category Ease of Use
New Attribute ➊
Description Creating new variables as a functional relationship of existing variables
 Benefits  Limitations
Make any univariate or multivariate computational
transformation of existing attributes
Any missing values in any of the original data will
produce a missing value in the computed attribute
Tool Math formula
Application Across the board
Example Net Rev = Units * (price - direct cost) - Fixed Cost
Technique Group ___ Category Ease of Use
Reduction ➌
Description For a specific variable calculate the statistic for that value - sum, average, SD etc
 Benefits  Limitations
Allows for comparison studies between states,
professions, divisions, etc.
What to do with missing values within a group so the
statistics can still be calculated
Tool Groupmean GroupSD
Application Social analysis, financial analysis, sport statistics
Example Groupmean(Table, ethnic)
Technique Lag
Category Ease of Use
New Attribute ➊
Description Moving the data upward or downward
 Benefits  Limitations
Can slide the data to make comparison of sequential
values
Values that don’t have a value to be moved into it
become missing values
Tool Lag Function
Application Time series analysis, differencing, runs
Example Lag(Table,”Rev”, 3) will move down 3 positions