Acknowledgements
This session of the course was written by Anna Page on behalf of the Free Learning team at The Open University.
Images
Figure 1: John T. Spencer https://www.flickr.com/ photos/ edrethink/ 8731759135 [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] CC-BY-2.0
Every effort has been made to contact copyright owners. If any have been inadvertently overlooked, the publishers will be pleased to make the necessary arrangements at the first opportunity.
7.3 Summary