Measurement Scales & Data Characteristics Flashcards
Types of Data
Variable, Data, and Factor
Variable - question or field name
Data - answer or observations about the variable
Factor - variable of interest in an analysis
4 Basic Measurement Scales
- Ratio
- Interval
- Ordinal
- Nominal
Measurement Scale Groupings
Quantitative/Qualitative
- Quantitative - numerical
- Discrete - whole numbers
- Continuous - decimals
- Qualitative - categorical
Cardinal and Count Data
Quantitative and discrete
Quantitative Continuous Scales
Interval and Ratio
Ratio -
absolute “zero” treated as the point of origin, and equal + definitive ratio between sets
can be multiplied
positive
Interval-
No absolute zero (temperature - Kelvin)
can be negative
Time Data Scale
- Continuous
- keeps restarting from zero at set periodicity
- distance b/w readings is measurable and comparable
- Need to consider seasons/time-zones
Qualitative Scales
-
Ordinal
- ordered
- distance b/w points not known or varies
- no absolute “zero”
- no math should be done on results
-
Nominal
- subgroups - with or without order and dichotomous
One hot encoding
Making qualitative data into 1s and 0s
New Data Types
- Images
- Video
- Audio
- GPS data
- Unstructured text
What affects data reliability?
NSFTEL
Data characteristics:
- Nature
- Source
- Format
- Timing
- Extent
- Level of aggregation
What is the importance of the nature of data?
- Financial vs nonfinancial
- Quantitative vs qualitative
- Completeness
- Accuracy
- Fitness for purpose
Reliability
Consistent and repeatable
Valid data
measures what you think it is measuring
Data quality
Data quality = reliability + validity
Data integrity as a subset of data quality
Characteristics
- Completeness
- Uniqueness
- consistency
- timeliness
- validity
- accuracy