@@ -10,9 +10,13 @@ This lesson shows how to use Python and scikit-image to do basic image processin
 
 This lesson assumes you have a working knowledge of Python and some previous exposure to the Bash shell.
 These requirements can be fulfilled by:
-a) completing a Software Carpentry Python workshop **or**
-b) completing a Data Carpentry Ecology workshop (with Python) **and** a Data Carpentry Genomics workshop **or**
-c) independent exposure to both Python and the Bash shell.
+
+- a) completing a Software Carpentry Python workshop
+- b) completing a Data Carpentry Ecology workshop (with Python) **and** a Data Carpentry Genomics workshop
+- c) independent exposure to both Python and the Bash shell.
+
+Note: this lesson also requires some basic familiarity with [NumPy](https://numpy.org/doc/stable/index.html) arrays. 
+For example, as covered in the Software Carpentry [Programming with Python lesson](https://swcarpentry.github.io/python-novice-inflammation/02-numpy.html).
 
 If you're unsure whether you have enough experience to participate in this workshop, please read over
 [this detailed list](learners/prereqs.md), which gives all of the functions, operators, and other concepts you will need