- Reviewing progress
- Methods
- Regional
Methods of reviewing progress - regional indicators
Not everyone is able to look at a graph and immediately understand the messages, and it is useful to be able to summarise what the indicators tell us. So to highlight whether or not things are moving in the right or wrong direction, a set of traffic lights are used.
The 'traffic lights' are:
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= clear improvement |
 |
= little or no change |
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= clear deterioration |
 |
= insufficient or no comparable data |
based on an assessment of the latest data compared with the position for earlier years.
For most indicators it will be very clear whether there has been an improvement or a deterioration, and hence whether a green or red traffic light is warranted. However where the amounts of change are small it can be difficult to judge whether they are sufficient to indicate that there has been a clear improvement or deterioration. So as a basic rule of thumb where an indicator value has changed by less than 3 per cent, the traffic light has been set at amber, indicating little or no change. The choice of 3 per cent as the threshold is arbitrary but has proven to be helpful in deciding on the most appropriate traffic light. There are a few exceptions to this rule, where for example the indicator has been historically stable and / or almost at the level it can be expected to achieve. In such cases a smaller amount of change may be regarded as indicating an improvement or deterioration. In one or two cases the level of change may be greater than 3 per cent but the traffic light is nevertheless amber. This will apply where the limits of data collection imply that a larger percentage change is necessary for it to be regarded as showing a clear change.
The choice of baselines is of course also to some extent arbitrary. The duration of time series data avaliable at a regional level is highly variable so all assessments have been made using the first available year as a baseline.
However, owing to year on year variation the position at the beginning of a time series may be unrepresentative of the trend and could unduly influence our assumptions about the degree of progress made. To reduce the impact of the precise baseline year, where possible a three-year average around the baseline year has been used. So an assessment of change since 1990 for example, will be based on a comparison of the latest year's data with the average of data for 1989-91, if data are available.
Indicator presentation
For each indicator that we have data for, one or more charts are provided. In most cases a bar chart compares regional performance with the national average for the earliest and latest data available. Where at least 5 years trend data is available a chart of each regions progress against the national average has been shown. The presentation of the charts has been simplified as far possible. For example on the x-axis not all years for which data are presented have been indicated.
Many indicators have several components and these may be shown as an index, which means that the value of the component for a base year, mainly 1990, is treated as representing 100 (per cent). Subsequent or preceding values of the indicator are then shown in relation to that base value - in effect as a percentage of it. This allows trends in components with different units to be more easily compared from the base year.
The traffic lights, summarising the medium and short-term change are shown beneath the charts. If trends in individual components of an indicator are moving in the same direction then a combined assessment will be made, rather than presenting multiple traffic lights.
A short statistical commentary on the indicator is then provided to highlight and explain the trends.
Updated: 07 March 2005