Skills Checklist

After completing this chapter you should be able to......

• recognise time series data

• construct a times series plot

• identify the presence of trend, cycles, seasonality, structural change and irregular (random) fluctuations in a time series plot

• smooth a time series to help identify any trend

• graphically smooth a time series plot using median smoothing

• calculate and interpret seasonal indicies

calculate and interpret a trend line for linear trends

• use a trend line to make forecasts

Key vocabulary

Patterns, Trend, Cycles, Seasonality, Structural Change, Outliers, Irregular fluctuations, Trend line, Time-series, Association Table, Time labels, Smoothing, Median Smoothing, Moving average smoothing, Cyclical variation, Centring, Seasonal Variation, Seasonal Index, Deseasonalising, Reseasonalizing, Actual, Correcting for seasonality, forecasting, predictions,