# Longitudinal Coherence – Two Definitions

During the process of writing my assignment, i came across two different meanings of longitudinal coherence which caused me to become slightly confused.

The mathematical term of longitudinal coherence, stated by Liping Ma, is described as the layering of the subject. This can be like the curriculum and how there are layers of various stages in each topic area and what each ability should be learning and implementing. Ma describes that the teachers must be aware of all levels and areas of the curriculum and not only the stages they are teaching or have taught. This, therefore, means that the teachers understand what their students have previously learnt and what they’ll be learning in the future in order to lay the right foundations for future lessons.

On the other hand, when I was searching for other definitions of longitudinal coherence, i found that this term also has a different scientific meaning. Within physics, this term is defined as the “distance over which two waves from the same source point with slightly different wavelengths will completely dephase”. As I have never understood physics, I don’t understand exactly what this describes. However, relating it to the assignment, I believed that it was explaining how two different topics may cross over or link as they contain basic areas which can be used within both or multiple topics. As this is very similar to interconnectedness, it caused confusion. However, i never realised that there are two completely different meanings for longitudinal coherence and the scientific definition, therefore, has no relation at all to the topic being discussed within my assignment.

Although the scientific meaning of longitudinal coherence relates in no form to the mathematical definition, i found it extremely intriguing. I believe the scientific meaning in a way, of what i understand, can in fact be an interesting description of how subjects or topic areas can be totally different, however, have similarities.

Segre, C. (2010) ‘Longitudinal Coherence’. PHYS 570: Physics. Available at: http://phys.iit.edu/~segre/phys570/10F/lecture_04.pdf (Accessed: 20 November 2016)