Types of Data

Types of Data

1. Categorical Data

   • Non-numerical data placed in exclusive categories and then counted rather than measured
   • Nominal
     • Assigning numbers to objects to indicate different objects
       • Numbers themselves have no real 'meaning' other than differentiating between objects
         • Data which cannot be ordered
           • E.g. Car registration number
   • Ordinal
     • Assigning numbers to objects (like nominal), but the numbers here have meaningful order
       • E.g. Places in a race - 1st, 2nd and 3rd (number indicates order)

2. Interval and Ratio Data

   • Ratio
     • Differences are meaningful (like interval), ratios are meaningful and there is meaningful zero
       • E.g. Weight - 10kg is twice as much as 5kg, (meaningful ratio of 1:2), 0kg means no weight (meaningful zero)
   • Interval
     • Numbers have order (like ordinal) but there are equal intervals between adjacent categories
       • E.g. Temperature- difference between 30°C and 50°C is same as difference between 40°C and 60°C, same interval of 20°C on this scale

3. Quantitative and Qualitative Data

   • Quantitative
     • Numerical information
       • Measured on interval or ratio scales
         • E.g. Height
         • May be discrete or continuous
   • Qualititative
     • May be numeric or non-numeric
       • Measured on nominal or ordinal scales only
         • E.g. Gender
       • E.g. '1' can denote Male and '2' can denote Female

4. Discrete and Continuous Data

   • Discrete
     • Can only take in certain value (often whole numbers)
       • E.g. Number of children (can't have 1.5 children)
   • Continuous
     • Can take any value within a range
       • E.g. Weight can be 132.2lbs as opposed to just 132 pounds

5. Scales of Measurement

   • Nominal
     • Ordinal
       • Interval
         • Ratio