This module is concerned with the process of estimation when we use a sample to give us some idea of what is happening in a larger population.

It covers a number of different aspects of this process. You will see button links at the top to take you directly to those sections if you have already visited this module before.

The button will always bring you back here. 

The button will give you access to a page with direct links to every page and every simulation worksheet in the module.

The button will give you access to other web-based resources that have been carefully selected by the authors to supplement the material here.

If you have not used any of the DISCUSS materials before, click here to see a brief introduction to how to make the best use of them and for the technical requirements.

There is also a 'recommended route' for you to work through this material in a logical order. The button link for the 'recommended route' at each stage will appear in red, so you should always be able to pick it up at any stage. There are a number of worksheets based on simulations which you can launch by clicking on the hyperlinks. When you finish, click on the continue button, at the top or bottom of the worksheet. You can still use your browser back button to return to the previous web page.

If you want to be able to come back to your answers at a future date, you will need to save the worksheet to a new file location when the browser prompts you.

We recommend that you open Excel now by clicking here. This will allow the interactive parts of the module to load much more quickly and you may also find it useful to have a blank spreadsheet available for you to go to sometimes.

We recommend you start by looking at why sampling is useful.  
Click on the Why Sample? button at the top of the page.

The interactive elements of this module use Microsoft Excel 97 and will not run unless this software (or a later version) is installed on your computer (or network).  Excel uses settings taken from the first worksheet opened in the session, so please ensure that you do not have Excel already running when you start to use any of our interactive elements. This site works most effectively when viewed using Internet Explorer.