diff --git a/polynomials/poly.rkt b/polynomials/poly.rkt
index fe87b3f32..9b0cb5d9d 100644
--- a/polynomials/poly.rkt
+++ b/polynomials/poly.rkt
@@ -3,6 +3,7 @@
 (module common racket/base
   (provide curly?)
   (define (curly? stx)
+    ; Was the form in stx written with curly parentheses?    
     (let ([p (syntax-property stx 'paren-shape)])
       (and p 
            (or (eqv? p #\{)
diff --git a/statistics/chi-squared-test.rkt b/statistics/chi-squared-test.rkt
index a54cede2a..cfd83b025 100644
--- a/statistics/chi-squared-test.rkt
+++ b/statistics/chi-squared-test.rkt
@@ -1,4 +1,9 @@
 #lang racket
+;;;
+;;; This module implements Chi-squared tests for goodness of fit and
+;;; independence of categories.
+;;;
+
 (require racket/flonum
          (planet williams/science:4:5/science)
          (only-in (planet williams/science/unsafe-ops-utils)