One of the main challenges teachers have to go through is how to evaluate our student's learning process. Traditionally, evaluation has been made through exams and plain exercises which, in my opinion, are rather thought for teachers to rate the student more easily, but don't really assess if they have learned the content properly.
For this reason, it is interesting to create rubrics with evaluating criteria, and to think of methods which go beyond the traditional ones. For example, the portfolio: a compilation of tasks which show the student's progress on the topic, they portray very faithfully how they have advanced through the units, and not only do they show the final result (as opposed to exams), but we can also see the difference between how the student did at the beginning and at the end. There are many tools to create rubrics, such as Rubrica or Corubrics, which make this job much easier, so we have actually no excuse to keep using the traditional memorisation method.
I think that evaluation really is an issue: teachers normally go through the easiest way to evaluate their students, without taking into account that they are perahps not evaluating them correctly. If we start using different evaluation techniques, we will be able to assess more accurately what students have learnt or not learnt, and thus know what to do for them to improve.
Cover image taken from the following link: https://www.un.org/democracyfund/Docs/PostProjectEvaluations.html