I am not sure of the difference between "Methods" and "Methodology". In my dissertation, how should I name the chapter that describes the tools and methods I used to obtain my result?
I use the following definition:
Methods are very simply, the things you did. The methods you used to achieve the result you're presenting. The could be new, or they could be existing methods.
A methodology is one level higher, a meta-method if you will. It is a method for creating a method. In other words a framework: a set of ideas and principles that can be applied to different contexts to create a specific method for that context.
So the line is a little blurry. If you're describing an experimental approach which is standard and unsurprising, you should definitely use methods. If the methods section is a part of the actual results you're presenting, you might use methodology, but only if you think it's sufficiently general.
As a policy, I would err on the side of caution and use methods if you're not sure. Using methodology when methods will do sounds pompous and unnecessarily complicates the text.