Formative assessment for manual editing

[alpha-beta-soup]

cf #67

Not an easy one for which to write a formative assessment in the middle, for reasons including that the point of this workshop is to teach Snakemake and at this point no Snakefiles have been seen. So I tried to recap the lesson conceptually with some questions for consideration after only a minor script edit. The questions are intended to reinforce ideas introduced in this episode:

• Computationally-expensive workflows mean that it's important to adopt a workflow tool that can work out what parts need to be updated in response to input changes.
• That static inputs may change independently and that it is an overhead to have to know about these changes.
• That a script is an input as well as a static file (book), by having students edit the graph style and then regenerate outputs. (In my experience it is revelatory to students to realise that scripts are entities that change in a similar way as static input files. This is a powerful idea that is important to introduce early since it has high value.)

I'm happy to make any suggested changes, or equally to have the whole assessment rejected for any reason.