diff --git a/cs622/proj3/notes.txt b/cs622/proj3/notes.txt
index 398d275..cd8b3ea 100644
--- a/cs622/proj3/notes.txt
+++ b/cs622/proj3/notes.txt
@@ -1,3 +1,9 @@
 - industrial case study
 - Extreme Programming (XP)
 - Agile
+- case studies lead to people in a field accepting results, but less than 10%
+of papers in respected journals involved a case study
+- ability to collect lightweight data influenced by presence of historical
+data, cooperativeness of personnel, availability of data, and tool support
+- Sabre Airline Solutions
+- {Construct, Internal, External, Experimental} Validity