diff --git a/README.md b/README.md
index 531ebbb2..9391542f 100644
--- a/README.md
+++ b/README.md
@@ -273,7 +273,16 @@ Returns the value for the specified *key* string. If the map does not have an en
 
 <a name="map_set" href="#map_set">#</a> <i>map</i>.<b>set</b>(<i>key</i>, <i>value</i>)
 
-Sets the *value* for the specified *key* string. If the map previously had an entry for the same *key* string, the old entry is replaced with the new value. Returns the map, allowing chaining.
+Sets the *value* for the specified *key* string. If the map previously had an entry for the same *key* string, the old entry is replaced with the new value. Returns the map, allowing chaining. For example:
+
+```js
+var m = map()
+    .set("foo", 1)
+    .set("bar", 2)
+    .set("baz", 3);
+
+m.get("foo"); // 1
+```
 
 <a name="map_remove" href="#map_remove">#</a> <i>map</i>.<b>remove</b>(<i>key</i>)
 
@@ -326,7 +335,16 @@ Returns true if and only if this set has an entry for the specified *value* stri
 
 <a name="set_add" href="#set_add">#</a> <i>set</i>.<b>add</b>(<i>value</i>)
 
-Adds the specified *value* string to this set. Returns the set, allowing chaining.
+Adds the specified *value* string to this set. Returns the set, allowing chaining. For example:
+
+```js
+var s = set()
+    .add("foo")
+    .add("bar")
+    .add("baz");
+
+s.has("foo"); // true
+```
 
 <a name="set_remove" href="#set_remove">#</a> <i>set</i>.<b>remove</b>(<i>value</i>)
 
diff --git a/package.json b/package.json
index c2e10b7f..3bb2db09 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "d3-arrays",
-  "version": "0.2.1",
+  "version": "0.3.0",
   "description": "Array manipulation, ordering, searching, summarizing, etc.",
   "keywords": [
     "d3",
diff --git a/test/map-test.js b/test/map-test.js
index cb8acac4..5a52d369 100644
--- a/test/map-test.js
+++ b/test/map-test.js
@@ -92,10 +92,8 @@ tape("map.size() returns the number of distinct keys", function(test) {
 });
 
 tape("map.clear() removes all entries", function(test) {
-  var m = arrays.map();
-  m.set("foo", 1);
-  m.set("bar", 2);
-  m.set("foo", 3);
+  var m = arrays.map().set("foo", 1).set("bar", 2).set("foo", 3);
+  test.equal(m.size(), 2);
   m.clear();
   test.equal(m.size(), 0);
   test.deepEqual(m.entries(), []);
@@ -159,9 +157,7 @@ tape("map.keys() returns an array of string keys", function(test) {
 });
 
 tape("map.keys() properly unescapes zero-prefixed keys", function(test) {
-  var m = arrays.map();
-  m.set("__proto__", 42);
-  m.set("$weird", 42);
+  var m = arrays.map().set("__proto__", 42).set("$weird", 42);
   test.deepEqual(m.keys().sort(), ["$weird", "__proto__"]);
   test.end();
 });
@@ -222,17 +218,13 @@ tape("map.has(key) empty maps do not have object built-ins", function(test) {
 });
 
 tape("map.has(key) can has keys using built-in names", function(test) {
-  var m = arrays.map();
-  m.set("__proto__", 42);
+  var m = arrays.map().set("__proto__", 42);
   test.equal(m.has("__proto__"), true);
   test.end();
 });
 
 tape("map.has(key) can has keys with null or undefined properties", function(test) {
-  var m = arrays.map();
-  m.set("", "");
-  m.set("null", null);
-  m.set("undefined", undefined);
+  var m = arrays.map().set("", "").set("null", null).set("undefined", undefined);
   test.equal(m.has(""), true);
   test.equal(m.has("null"), true);
   test.equal(m.has("undefined"), true);
@@ -348,10 +340,7 @@ tape("map.set(key, value) can replace values", function(test) {
 });
 
 tape("map.set(key, value) can set null, undefined or empty string values", function(test) {
-  var m = arrays.map();
-  m.set("", "");
-  m.set("null", null);
-  m.set("undefined", undefined);
+  var m = arrays.map().set("", "").set("null", null).set("undefined", undefined);
   test.equal(m.get(""), "");
   test.equal(m.get("null"), null);
   test.equal(m.get("undefined"), undefined);
diff --git a/test/set-test.js b/test/set-test.js
index 8697a948..33387947 100644
--- a/test/set-test.js
+++ b/test/set-test.js
@@ -52,10 +52,8 @@ tape("set.size() returns the number of distinct values", function(test) {
 });
 
 tape("set.clear() removes all values", function(test) {
-  var s = arrays.set();
-  s.add("foo");
-  s.add("bar");
-  s.add("foo");
+  var s = arrays.set().add("foo").add("bar").add("foo");
+  test.equal(s.size(), 2);
   s.clear();
   test.equal(s.size(), 0);
   test.deepEqual(s.values(), []);
@@ -202,15 +200,13 @@ tape("set.add(value) returns the set", function(test) {
 });
 
 tape("set.add(value) can add values using built-in names", function(test) {
-  var s = arrays.set();
-  s.add("__proto__");
+  var s = arrays.set().add("__proto__");
   test.equal(s.has("__proto__"), true);
   test.end();
 });
 
 tape("set.add(value) can add values using zero-prefixed names", function(test) {
-  var s = arrays.set();
-  s.add("$weird");
+  var s = arrays.set().add("$weird");
   test.equal(s.has("$weird"), true);
   test.end();
 });
@@ -228,10 +224,7 @@ tape("set.add(value) coerces values to strings", function(test) {
 });
 
 tape("set.add(value) can add null, undefined or empty string values", function(test) {
-  var s = arrays.set();
-  s.add("");
-  s.add("null");
-  s.add("undefined");
+  var s = arrays.set().add("").add("null").add("undefined");
   test.equal(s.has(""), true);
   test.equal(s.has("null"), true);
   test.equal(s.has("undefined"), true);