Descriptive Statistics Flashcards
What are the levels of measurement from lowest to highest in terms of value?
- Nominal
- Ordinal
- Interval
- Ratio
What is the Nominal scale of measurement?
- Measure of identity or category
- Useful for quantifying qualitative data
- Does not provide order or magnitude
What is the Ordinal scale of measurement?
- A measure of order or rank
- Used to arrange data in series
- Does not provide info regarding magnitude of difference between ranks
What is the Interval scale of measurement?
- Measure of order and quantity
- Differences between values can be calculated
- Cannot establish an ‘x-fold’ increase between values
What is the Ratio scale of measurement?
- Interval scale with absolute zero, ‘x-fold’ differences can be calculated
- Subsumes all other levels of measurement
What are the SI Units for Distance, Mass, Time, Temperature, Mole, Current and Luminance?
- Metres
- Kilograms
- Seconds
- Kelvin
- Moles
- Amperes
- Candela
What is a discrete variable?
- Cannot be sub-divided
- Used to describe specific and distinct points on a scale
- E.g. Sex, RPE, Heart Rate
What is a continuous variable?
- Can theoretically take any value between two points on a continuum, e.g. Time
What are the three indicators of central tendency?
- Mode
- Median
- Mean
What are the disadvantages of using the Mode?
- Terminal statistic (can’t do anything else with the info)
- A given sub-group could make this measure unrepresentative
What are the advantages of using the Mode?
- Quick and Easy
- Unaffected by Extreme Scores
- Can be used at any level of measurement
What is the Mode?
the most frequently occurring score
What is the Median?
The middle score
What are the advantages of using the Median?
- Unaffected by extreme scores
- Can be used on all levels except nominal
What are the disadvantages of using the Median?
- Only considers order, value ignored