Individual, discrete and continuous series
Also called: Ungrouped data, Grouped data · Topic: Economic Data: Census, NSS, Surveys and Statistical Tools · NCERT: Class 11, Ch 5 "Measures of Central Tendency"
Meaning
These are the three forms in which data can be arranged to calculate averages and other measures.
- Individual series (ungrouped data): each observation is listed separately. Mean = ΣX/N.
- Discrete series: each distinct value is shown with its frequency, meaning how often it occurs. Mean = Σfx/Σf.
- Continuous series: data are grouped into class intervals with frequencies. Each class is represented by its class mark (mid-point) = (UL + LL)/2. Mean = Σfm/Σf.
Discrete and continuous series are both grouped data.
Example
Individual series: five farm incomes of 500, 550, 600, 650 and 700. Discrete series: household size 1, 2, 3 … with the number of households at each size. Continuous series: marks of 100 students in classes 0-10 (1 student), 10-20 (8 students), and so on.
Don't confuse with
- Discrete vs continuous variable: this is about the nature of the variable itself. A discrete variable moves in jumps, such as a number of students. A continuous variable can take any value, such as height. A series is about how the data are arranged.