How do I talk about methodology mistakes In a scientific project report? I'm writing up my 3rd year engineering project (The equivalent of a dissertation in other subjects), and I'm struggling to write the chapter in which my method failed I couldn't get any results.

My project is on Neural Networks, and when I started my project I tried to program my own Neural Network from scratch, however this did not work properly (The feed forward part worked, but because of the convoluted way I had programmed it I couldn't implement the back propagation part). After I realized this I used an off-the-shelf program to create my neural network, which worked much better.

The problem is that I must have spent about a quarter of the year programming my own Neural Network from scratch, so I want to include it as a chapter in my report to show the marker that I have put over the recommended 300 hours work into my project, and that I understand the inner working of Neural Networks.

How should I write this chapter? So far I have started the chapter as if it is going to work, then I wrote about exactly what I have done and how it works, and then at the end where the results should be I want to explain that the custom implementation of the neural network meant that I couldn't implement back propagation, and therefore couldn't get results. But I can't do this without it looking like I have lazily given up on that chapter, and abruptly given an excuse to move on to the next chapter (The working version of the neural network).
You wrote:


  I want to include it as a chapter in my report to show the marker that I have put over the recommended 300 hours work into my project


Nooooooooo.

Don't do that. This is a postgraduate degree, and you're expected to take the research seriously. It's not a 9-5 grunt job or prison sentence where you turn up, serve your time, and get the reward at the end of your allotted time.

Show what you've learnt. That's what the markers are interested in. You say that you've learnt the inner workings of neural networks. That's great. So demonstrate and document what you've learnt.

And don't document the tortuous process you used. Don't describe how you went from A to B via C,D,E,...X,Y.

Just report that you started at A, ended at B, you've found that the shortest route between those points is {whatever it is}, and briefly document the dead ends and traps that future researchers should avoid.