Statistics and simple questions

Students are usually taught statistics in the context of well-defined questions. For example,

Students are usually presented with relevant data and asked to draw a conclusion. Although it is important to master the statistical techniques to extract information from pre-collected data,

The use of statistics in the real world is rarely so simple.

Statistics for complex problems

In practice, problems are rarely so well-defined and there may be various different ways to collect data to throw light on them.

Collection and analysis of data to help attack the problem usually suggest further questions for which further data are required. Several cycles of data collection and analysis are usually needed, with considerable input from an expert in the problem area between each cycle of the process.

Continuous quality improvement

One important example of this type of continuing process arises in business and industrial contexts where statistics is an important part of the long-term monitoring of performance. The process may simply monitor existing systems to ensure that they continue to perform at their current levels, or the aim may be to improve aspects of the system. The latter is often called continuous quality improvement or total quality management.

Detecting problems

Problems in a process are usually detected by collecting and analysing data about the performance of the system. Various different types of data can be collected to throw light on the performance of a system. In this section, we describe one particularly useful way to monitor processes.

Control charts are an important tool for detection of problems in a process.