Modal dialog for ipykernel installs & better messages

When running a notebook without ipykernel the user will be presented with the same message today, but modal diaglog as follows:

Should probably change the message, doesn’t seem to be descriptive enought. Feels way too technical. Someone starting jupyter notebooks or not aware of ipykernel will just ignore this.

It should ideally be along the lines: In order to run notebooks IPykernel needs to be installed, do you want to install ipykernel?

[greazer]

I don’t think we need an experiment, yet. We are trying to find out whether users are simply not seeing the notification or whether they are just ignoring (by accident or on purpose). Putting the same message in a modal dialog box can certainly help answer the question as to whether they ignoring the message. To do so, we would just leave the message and operations the same, just make it modal.

However, if you try and “get into the heads” of some of our pure Jupyter customers it seems highly likely that many, if not most, of them will have zero familiarity with ipykernel itself. If so, that definitely would affect how they respond to any such notification regardless of whether it’s modal or not. “I’m trying to use a Jupyter notebook. What does this ipykernel thing have to do with that?” I don’t think we need an experiment to check this hypothesis either.

I don’t think it hurts to make this message modal since the user is clearly trying to run a cell and simply will not be able to. Putting up a message to clearly indicate that they are blocked from what they are attempting to do seems completely reasonable.

With all that said, I would propose that we go ahead with a modal solution but change the message to say:

 "Running cells requires either Jupyter or the ipykernel package to be installed. __Learn More...__"

           "Install Jupyter" / "Install ipykernel" / "Choose different kernel" / "Cancel" 

“Learn More…” is a link or some “additional info” affordance to a page describing this problem.

I assume we can have 4 buttons. “Choose different kernel” isn’t technically necessary and I’m not even sure if it’s appropriate based on our current kernel finding algorithm. But I think it could help new users find an appropriate kernel without relying on them to find how to change it themselves, thus improving first-time success. It can also provide telemetry to help us understand whether users HAVE appropriate kernels available, but aren’t getting selected correctly.

Note that if the user presses “Choose different kernel” then the kernel should be chosen and the run operation should be attempted automatically. If the new kernel still isn’t good, then the same modal dialog would appear.

[claudiaregio]

ideally we run one version against the one we have today which most people appear to “ignore”, but if we have to a/b/n it we can do that too. I think I can narrow this down to one version to test