diff --git a/README.md b/README.md
index b370285..1df50b8 100644
--- a/README.md
+++ b/README.md
@@ -3,5 +3,15 @@ Genomics
 
 Experiments with Python and Genomics
 
-THese are files related to experiments with Python and Bioinformatics, especially Rosalind.
+These are files related to experiments with Python and Bioinformatics, especially Rosalind.
 It is also a place to try working with Git.
+
+The file names are sometimes opaque.  One way to figure out what the
+programs do is to look at the "open" command, which should have the
+form:
+open("rosalind_xxxx","rU")
+Then the xxxx is a key to which Rosalind problem is solved.
+
+Obviously I should have named the programs more systematically.  Live
+and learn.
+