Time series
Also called: Time series data · Topic: Economic Data: Census, NSS, Surveys and Statistical Tools · NCERT: Class 11, Ch 3 "Organisation of Data"; Class 11, Ch 4 "Presentation of Data"; Class 11, Ch 8 "Use of Statistical Tools"
Meaning
A time series is data arranged in time order: by year, quarter, month or census round. It can also be seen as data on two variables where one of them is time. Arranging data by time is called chronological classification. It lets us see a series' long-run trend, its seasonal and cyclical patterns, and one-off shocks. It is usually shown on an arithmetic line graph, with time on the X-axis.
Example
India's population by census year: 35.7 crore (1951), 43.8, 54.6, 68.4, 81.8, 102.7, and 121.0 crore (2011).
Don't confuse with
- Spatial classification: this arranges data by place, not time. An example is wheat yield in 2013 across India, France, China and other countries.
Related concepts
- Trend
- Seasonality
- Cyclicity
- Compound annual growth rate
- Leading indicators
- Purchasing Managers' Index