diff --git a/inst/anc/index.html b/inst/anc/index.html
index 64fcc76..0f3bdbc 100644
--- a/inst/anc/index.html
+++ b/inst/anc/index.html
@@ -356,17 +356,22 @@
 lives saved using the _Results → Maternal_ menu, and number of
 stillbirths prevented in the _Results → Stillbirth_ menu.
 
-# Evaluate the relative effectiveness of ANC
+Enter the values from Spectrum into the [ANC Impact Google
+Spreadsheet](https://docs.google.com/spreadsheets/d/1bdJjavgBQ9Q5ZU7ODK0jO0VvNO24V2TCifoAj8DEkEc/edit?usp=sharing).
+
+# Explore the relative effectiveness of ANC
 
 In the _LiST_ module, click _Effectiveness_ → Effectiveness of
 interventions (maternal)_. You will see numbers between 0 and 1 in a
 series of tables, or empty tables.  These numbers are "effectiveness",
 which is defined as "the fraction of deaths due to a specific cause
-that are reduced by the intervention".  These numbers tell you how
-many deaths a particular intervention prevented for a particular
-segment (maternal, in this example), divided by the total number of
-deaths in the segment. You can assess which ANC interventions were
-most effective in saving lives, if any, for this particular population
+that are reduced by the intervention", and "affected fraction", which
+is "the fraction of deaths due to a specific cause that are
+potentially able to be impacted by a specific intervention".
+"Effectiveness" tells you how many deaths a particular intervention
+prevented for a particular segment (maternal, in this example),
+divided by the total number of deaths in the segment. "Affected
+fraction" tells you how many that intervention has reached, again by
 segment.
 
 As before, you can repeat this exercise for each segment.