Acknowledgements

This content is made available under a Creative Commons Attribution-Share Alike 4.0 licence. You are free to use, adapt and re-use this material as long as you credit The Open University, OpenSTEM Africa appropriately and license the material under the same terms. For more information visit http://creativecommons.org/licenses/by-sa/4.0/

Grateful acknowledgement is made to the following sources:

• Ministry of Education logo, used with permission from Ghana Ministry of Education
• CENDLOS logo, used with permission from CENDLOS
• OPITO logo, used with permission from OPITO
• Figures 1a, 2, 3, 4, 5 & 6: The Open University

Every effort has been made to contact copyright owners. If any have been inadvertently overlooked, the publisher will be please to make necessary arrangements at the first opportunity.