i. Long Term Trend

Discuss the trend first.

• • The trend gives us the general direction in which the data is headed.

  • The trend is the average of the series data and is determined by a process called 'smoothing'.

  • Start with an 'eyeball description' of whether the series is increasing, decreasing or remaining constant. This can then be improved by looking at start and end values of the trend line.

  • Describe these changes in context by stating the rate of change that is occurring.

Remember:

• To get higher grades, you need to contextualise your findings.

• Once you have performed your analysis, you will need to relate your findings back to the problem you are investigating.

  • • i.e What do the numbers tell you about what is happening in the real world problem you are studying?

Discussing the overall trend involves describing what is happening to the blue line on our recomposed data graphs.

Is it increasing, decreasing or doing something else?

Describe this with numbers. Specify exact locations on the graph with dates to back up your comments.

For higher grades you should be describing the changes in the trend in context and linking it to your purpose. You should always start by stating the start and finish values, and then elaborate on what is happening in between. You could also think about how much of the variation in the raw data is due to the change in this trend.

For each of the graphs write a comment about the long term trend.

The first two have been done for you.