Linear trend estimation
![Red shaded values are greater than 99% of the rest; blue, 95%; green, 90%. In this case, the V values discussed in the text for (one-sided) 95% confidence is seen to be 0.2.](/Images/godic/202502/17/Random-trends-histogram1229.png")
![Illustration of the effect of filtering on r2. Black=unfiltered data; red=data averaged every 10 points; blue=data averaged every 100 points. All have the same trend, but more filtering leads to higher r2 of fitted trend line.](/Images/godic/202502/17/Random-data-plus-trend-r21229.png")
Trend estimation is a statistical technique to aid interpretation of data. When a series of measurements of a process are treated as a time series, trend estimation can be used to make and justify statements about tendencies in the data, by relating the measurements to the times at which they occurred. This model can then be used to describe the behaviour of the observed data.