Video #17 (Levels of Measurement) Flashcards
What are the two reasons we use numerical data?
1) They are understood by the computer
2) They can be subject to mathematical operations
Why do we use numerical values?
To represent phenonmena
What the scales of measurement?
Nominal, Ordinal, Interval, Ratio (NOIR)
What is nominal data?
Data can only be named
What is ordinal data?
Data can be ordered, but still only named
What is interval data?
The gap between the values is important rather than the value itself
What is ratio data?
Data with values
Why should we use numerical data?
Numerical data allows for implications to be present about the data
What does the “group” data operation do?
The operation creates broader categories for nominal and ordinal data (Richmond, Burnaby, Abbotsford, Mission —> GVA, Fraser Valley)
What does the “isolate” data function do?
The isolate function can select any data type and set others aside
What are things you can’t do with numerical operations in GIS?
1) Multiply nominal or ordinal data
2) Divide or multiply two different types of data (#10 best cityx100,000 people doesn’t show us anything important
What are some things you can do with numerical operations?
1) Divide population by area (ratio data) to get pop. density
2) Subtract elevation B by elevation A to get difference of elevation
What is the benefit of having bigger numbers in your data?
It allows for a stronger basis for analysis
