Lab - $group and Accumulators

In the first part of the question it says

In the last lab, we calculated a normalized rating that required us to know what the minimum and maximum values for imdb.votes were. These values were found using the $group stage!

Did I miss a lab, where we did some grouping of the normalised rating? The last lab I did was Chapter 2: Basic Aggregation - LAB - Bringing it all together?


Yes, it refers to the “Chapter 2 LAB - Bringing it all together”, which does not calculate the normalized rating using $group. Will pass this to the curriculum developers to edit the text. Thank you very much for pointing this out.

José Carlos

I’m writing to say that as at Jan 2021, the text has not been edited to reflect that the normalized rating calculation was done in the $project stage rather than $group


The thing is, that all of the heavy lifting in actually creating the course content is done, this is about fine tuning that content for clarity.

I know I sound very whiney, but I do appreciate the content that has been created, but it’s about taking that content from A to A+. Possibly I have a bad case of OCD ?

Hi @NMullins, @Neil_01783,

We understand that the course content needs to be updated. We are already working on that while we are discussing these issues.

The course needs a major revamp and both content and delivery need to be changed in this case.
Therefore we are not making changes to the current version. We will soon be updating regarding the launch of a new revamped course.

Please feel free to reach out if you have any questions.

Kind Regards,

1 Like

So, I just got back to this section, and remembered it again.

Yep the real work was using the $regex to find the “Won digits Oscar…”, which I wasn’t that familiar with, and still aren’t 2 years later.

If this question stays in the rework, then a pointer in the notes for $regex would be a benefit.

Also the regex in the solution should have oscar? not oscars? since that oscars? gives the wrong answer. It excludes all the “Won 1 Oscar”


we don’t need to use regex, as the course is not yet at that level. so in this case we can use just simple functions like “$split” and “$arrayElemAt” and filter out “Won” and “no.of Oscars”

I hope this works.

Anil Kumar G