diff --git a/collects/teachpack/htdp/Docs/dir.thtml b/collects/teachpack/htdp/Docs/dir.thtml
index 3be73cc43c..8ff9259cdf 100644
--- a/collects/teachpack/htdp/Docs/dir.thtml
+++ b/collects/teachpack/htdp/Docs/dir.thtml
@@ -4,7 +4,7 @@
 <p>The teachpack <code>dir.ss</code> provides two-structures and one
 operation:
 <menu>
-  <li> <code>(define-struct dir (names dirs files))</code>
+  <li> <code>(define-struct dir (name dirs files))</code>
 
   <li> <code>(define-struct file (name size content))</code>
 
@@ -15,10 +15,10 @@ operation:
 <p>The teachpack relies on two data definitions:
 <menu>
 <li>
-   A directory is
-   <code>({(idx make-dir)} string[path] (listof directory) (listof file))</code>
+   A Directory is
+   <code>({(idx make-dir)} string[path] (listof Directory) (listof File))</code>
 <li>
-   A file is <code>({(idx make-file)} string[file name])</code>
+   A File is <code>({(idx make-file)} String PositiveNumber (listof Char))</code>
 </menu>
 
 Sample: Set teachpack to <code>dir.ss</code> and execute. Then evaluate
diff --git a/collects/teachpack/htdp/Docs/world.thtml b/collects/teachpack/htdp/Docs/world.thtml
index ab2d3cf97c..223f215eb3 100644
--- a/collects/teachpack/htdp/Docs/world.thtml
+++ b/collects/teachpack/htdp/Docs/world.thtml
@@ -83,7 +83,10 @@ students to simulate a small world of animated drawings and games:
    <code>(add-line scene x0 y0 x1 y1 c)</code>
    places a line of color <code>c</code> from <code>(x0,y0)</code> to
    <code>(x1,y1)</code> into <code>scene</code>;  
-   <code>(x,y)</code> are comp. graph. coordinates
+   <code>(x,y)</code> are comp. graph. coordinates; 
+   in contrast to the {(idx image.ss)} <code>add-line</code> function, this
+   one cuts off those portions of the line that go beyond the boundaries of
+   the given <code>Scene.</code>
    
 <li><code>{(idx run-movie)}   : (Listof Image) -> true </code><br>
    <code>(run-movie loi)</code>