diff --git a/.travis.yml b/.travis.yml
index b7484b6..4cbb75e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,5 +3,3 @@ node_js:
   - '5'
   - '4'
   - '0.12'
-before_script:
-  - npm install -g jasmine-node
\ No newline at end of file
diff --git a/README.md b/README.md
index 097c301..f5785ff 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ wordpos
 
 wordpos is a set of *fast* part-of-speech (POS) utilities for Node.js using fast lookup in the WordNet database. 
 
-Version 1.x is a mojor update with no direct depedence on [natural's](http://github.com/NaturalNode/natural), with support for Promises, and roughly 5x speed improvement over previous version. 
+Version 1.x is a major update with no direct dependence on [natural's](http://github.com/NaturalNode/natural), with support for [Promises](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise), and roughly 5x speed improvement over previous version. 
  
 **CAUTION** The WordNet database [wordnet-db](https://github.com/moos/wordnet-db) comprises [155,287 words](http://wordnet.princeton.edu/wordnet/man/wnstats.7WN.html) (3.0 numbers) which uncompress to over **30 MB** of data in several *un*[browserify](https://github.com/substack/node-browserify)-able files.  It is *not* meant for the browser environment.
 
@@ -104,7 +104,7 @@ wordpos.getPOS(text, callback) -- callback receives a result object:
 ```
 
 If you're only interested in a certain POS (say, adjectives), using the particular getX() is faster
-than getPOS() which looks up the word in all index files. [stopwords](https://github.com/moos/wordpos/lib/natural/util/stopwords.js)are stripped out from text before lookup.
+than getPOS() which looks up the word in all index files. [stopwords](lib/natural/util/stopwords.js) are stripped out from text before lookup.
 
 If `text` is an *array*, all words are looked-up -- no deduplication, stopword filtering or tokenization is applied.
 
@@ -127,8 +127,7 @@ wordpos.getPOS('The angry bear chased the frightened little squirrel.', console.
   }
 
 ```
-This has no relation to correct grammar of given sentence, where here only 'bear' and 'squirrel'
-would be considered nouns. 
+This has no relation to correct grammar of given sentence, where here only 'bear' and 'squirrel' would be considered nouns. 
 
 #### isNoun(word, callback)
 #### isVerb(word, callback)
@@ -228,7 +227,33 @@ Access the array of stopwords.
 
 ## Promises
 
-TODO
+As of v1.0, all `get`, `is`, `rand`, and `lookup`  methods return a standard ES6 [Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise).
+
+```js
+wordpos.isVerb('fish').then(console.log);
+// true
+```
+
+Compound, with error handler:
+
+```js
+wordpos.isVerb('fish')
+  .then(console.log)
+  .then(doSomethingElse)
+  .catch(console.error);
+```
+
+Callbacks, if given, are executed _before_ the Promise is resolved.
+
+```js
+wordpos.isVerb('fish', console.log)
+  .then(console.log)
+  .catch(console.error);
+// true 'fish' 13
+// true
+```
+Note that callback receives full arguments (including profile, if enabled), while the Promise receives only the result of the call.  Also, beware that exceptions in the _callback_ will result in the Promise being _rejected_ and caught by `catch()`, if provided.
+
 
 ## Fast Index
 
@@ -236,7 +261,7 @@ Version 0.1.4 introduces `fastIndex` option.  This uses a secondary index on the
 
 Fast index improves performance **30x** over Natural's native methods. See blog article [Optimizing WordPos](http://blog.42at.com/optimizing-wordpos).
 
-As of version 1.0, the fast index option is always on and cannot be turned off.
+As of version 1.0, fast index is always on and cannot be turned off.
 
 ## Command-line: CLI
 
@@ -245,73 +270,15 @@ For CLI usage and examples, see [bin/README](bin).
 
 ## Benchmark
 
-Note: `wordpos-bench.js` requires a [forked uubench](https://github.com/moos/uubench) module.
-
-    cd bench
-    node wordpos-bench.js
-
-
-512-word corpus (< v0.1.4, comparable to Natural) :
-```
-  getPOS : 0 ops/s { iterations: 1, elapsed: 9039 }
-  getNouns : 0 ops/s { iterations: 1, elapsed: 2347 }
-  getVerbs : 0 ops/s { iterations: 1, elapsed: 2434 }
-  getAdjectives : 1 ops/s { iterations: 1, elapsed: 1698 }
-  getAdverbs : 0 ops/s { iterations: 1, elapsed: 2698 }
-done in 20359 msecs
-```
-
-512-word corpus (as of v0.1.4, with fastIndex) :
-```
-  getPOS : 18 ops/s { iterations: 1, elapsed: 57 }
-  getNouns : 48 ops/s { iterations: 1, elapsed: 21 }
-  getVerbs : 125 ops/s { iterations: 1, elapsed: 8 }
-  getAdjectives : 111 ops/s { iterations: 1, elapsed: 9 }
-  getAdverbs : 143 ops/s { iterations: 1, elapsed: 7 }
-done in 1375 msecs
-```
-
-220 words are looked-up (less stopwords and duplicates) on a win7/64-bit/dual-core/3GHz.  getPOS() is slowest as it searches through all four index files.
-
-### Version 1.0 Benchmark
-
-Re-run v0.1.16:
-```
-  getPOS : 11 ops/s { iterations: 1, elapsed: 90 }
-  getNouns : 21 ops/s { iterations: 1, elapsed: 47 }
-  getVerbs : 53 ops/s { iterations: 1, elapsed: 19 }
-  getAdjectives : 29 ops/s { iterations: 1, elapsed: 34 }
-  getAdverbs : 83 ops/s { iterations: 1, elapsed: 12 }
-  lookup : 1 ops/s { iterations: 1, elapsed: 720 }
-  lookupNoun : 1 ops/s { iterations: 1, elapsed: 676 }
-
-looked up 220 words
-done in 2459 msecs
-```
-
-V1.0:
-```
-  getPOS : 14 ops/s { iterations: 1, elapsed: 73 }
-  getNouns : 26 ops/s { iterations: 1, elapsed: 38 }
-  getVerbs : 42 ops/s { iterations: 1, elapsed: 24 }
-  getAdjectives : 24 ops/s { iterations: 1, elapsed: 42 }
-  getAdverbs : 26 ops/s { iterations: 1, elapsed: 38 }
-  lookup : 6 ops/s { iterations: 1, elapsed: 159 }
-  lookupNoun : 13 ops/s { iterations: 1, elapsed: 77 }
-
-looked up 221 words
-done in 1274 msecs
-```
-That's roughly **2x** better across the board.  Functions that read the data files see much improved performance: `lookup` about **5x** and `lookupNoun` over **8x**. 
-
+See [benchmark](benchmark/README).
 
 ## Changes
 
-1.0.1
- - Removed direct dependency on Natural.  Certain modules are included in /lib.
- - Add support for Promises.
- - Improved data file reads for up to **5x** performance increase.
- - Tests are now mocha-based with assert interface.
+1.0.0
+ - Removed npm dependency on Natural.  Certain modules are included in /lib.
+ - Add support for ES6 Promises.
+ - Improved data file reads for up to **5x** performance increase compared to previous version.
+ - Tests are now [mocha](https://mochajs.org/)-based with [chai](http://chaijs.com/) assert interface.
 
 0.1.16 
  - Changed dependency to wordnet-db (renamed from WNdb)
diff --git a/bench/README.md b/bench/README.md
new file mode 100644
index 0000000..e658ce5
--- /dev/null
+++ b/bench/README.md
@@ -0,0 +1,80 @@
+## Benchmark
+
+```bash
+    cd bench
+    node wordpos-bench.js
+```
+
+### Version 1.0 Benchmark
+
+The following benchmarks were run on a Win8.1/Core i7/3.5GHz machine on a Seagate 500GB SATA II, 7200 RPM disk.  The corpus was a 512-word text, with stopwords and duplicates removed, resulting in 220 words looked-up. 
+
+#### Pre v0.14 (comparable to Natural)
+```
+  getPOS : 1 ops/s { iterations: 1, elapsed: 1514 }
+  getNouns : 2 ops/s { iterations: 1, elapsed: 409 }
+  getVerbs : 2 ops/s { iterations: 1, elapsed: 418 }
+  getAdjectives : 3 ops/s { iterations: 1, elapsed: 332 }
+  getAdverbs : 4 ops/s { iterations: 1, elapsed: 272 }
+  lookup : 1 ops/s { iterations: 1, elapsed: 1981 }
+  lookupNoun : 0 ops/s { iterations: 1, elapsed: 2016 }
+
+looked up 220 words
+done in 7770 msecs
+```
+
+#### v0.1.16 (with fastIndex):
+```
+  getPOS : 11 ops/s { iterations: 1, elapsed: 90 }
+  getNouns : 21 ops/s { iterations: 1, elapsed: 47 }
+  getVerbs : 53 ops/s { iterations: 1, elapsed: 19 }
+  getAdjectives : 29 ops/s { iterations: 1, elapsed: 34 }
+  getAdverbs : 83 ops/s { iterations: 1, elapsed: 12 }
+  lookup : 1 ops/s { iterations: 1, elapsed: 720 }
+  lookupNoun : 1 ops/s { iterations: 1, elapsed: 676 }
+
+looked up 220 words
+done in 2459 msecs
+```
+
+#### v1.0:
+```
+  getPOS : 14 ops/s { iterations: 1, elapsed: 73 }
+  getNouns : 26 ops/s { iterations: 1, elapsed: 38 }
+  getVerbs : 42 ops/s { iterations: 1, elapsed: 24 }
+  getAdjectives : 24 ops/s { iterations: 1, elapsed: 42 }
+  getAdverbs : 26 ops/s { iterations: 1, elapsed: 38 }
+  lookup : 6 ops/s { iterations: 1, elapsed: 159 }
+  lookupNoun : 13 ops/s { iterations: 1, elapsed: 77 }
+
+looked up 221 words
+done in 1274 msecs
+```
+
+These are **3.5x** better compared to v0.1.16 and **15x** better compared to pre v0.14, overall.  Functions that read the data files see much improved performance: `lookup` about **13x** and `lookupNoun` **26x** compared to pre v0.14. 
+
+
+### Old benchmark
+
+512-word corpus (< v0.1.4, comparable to Natural) :
+```
+  getPOS : 0 ops/s { iterations: 1, elapsed: 9039 }
+  getNouns : 0 ops/s { iterations: 1, elapsed: 2347 }
+  getVerbs : 0 ops/s { iterations: 1, elapsed: 2434 }
+  getAdjectives : 1 ops/s { iterations: 1, elapsed: 1698 }
+  getAdverbs : 0 ops/s { iterations: 1, elapsed: 2698 }
+done in 20359 msecs
+```
+
+512-word corpus (as of v0.1.4, with fastIndex) :
+```
+  getPOS : 18 ops/s { iterations: 1, elapsed: 57 }
+  getNouns : 48 ops/s { iterations: 1, elapsed: 21 }
+  getVerbs : 125 ops/s { iterations: 1, elapsed: 8 }
+  getAdjectives : 111 ops/s { iterations: 1, elapsed: 9 }
+  getAdverbs : 143 ops/s { iterations: 1, elapsed: 7 }
+done in 1375 msecs
+```
+
+220 words are looked-up (less stopwords and duplicates) on a win7/64-bit/dual-core/3GHz.  getPOS() is slowest as it searches through all four index files.
+
diff --git a/bench/wordpos-bench.js b/bench/wordpos-bench.js
index 715cb6c..87361eb 100644
--- a/bench/wordpos-bench.js
+++ b/bench/wordpos-bench.js
@@ -1,15 +1,23 @@
+/**
+ * wordpos-bench.js
+ *
+ * Copyright (c) 2012-2016 mooster@42at.com
+ * https://github.com/moos/wordpos
+ *
+ * Released under MIT license
+ */
 
-var uubench = require('uubench'), // from: https://github.com/moos/uubench
+var Bench = require('mini-bench'),
   fs = require('fs'),
   _ = require('underscore')._,
   WordPOS = require('../src/wordpos'),
   wordpos = new WordPOS();
 
 
-suite = new uubench.Suite({
+suite = new Bench.Suite({
   type: 'fixed',
   iterations: 1,
-  sync: true,	// important!
+  async: false,	// important!
 
   start: function(tests){
     console.log('starting %d tests', tests.length);
@@ -110,6 +118,7 @@ suite.section('--512 words--', function(next){
   suite.options.iterations = 1;
   next();
 });
+
 suite.bench('getPOS', getPOS);
 suite.bench('getNouns', getNouns);
 suite.bench('getVerbs', getVerbs);
@@ -118,6 +127,4 @@ suite.bench('getAdverbs', getAdverbs);
 suite.bench('lookup', lookup);
 suite.bench('lookupNoun', lookupNoun);
 
-
-
 suite.run();
diff --git a/package.json b/package.json
index 9d54917..58b4d53 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,15 @@
 {
   "name": "wordpos",
   "author": "Moos <mooster@42at.com>",
-  "keywords": ["natural", "language", "wordnet", "adjectives", "nouns", "adverbs", "verbs"],
+  "keywords": [
+    "natural",
+    "language",
+    "wordnet",
+    "adjectives",
+    "nouns",
+    "adverbs",
+    "verbs"
+  ],
   "description": "wordpos is a set of part-of-speech utilities for Node.js using the WordNet database.",
   "version": "1.0.0-RC1",
   "homepage": "https://github.com/moos/wordpos",
@@ -10,18 +18,18 @@
   },
   "bin": "./bin/wordpos-cli.js",
   "dependencies": {
+    "commander": "^2.0.0",
     "underscore": ">=1.3.1",
-    "wordnet-db": "latest",
-    "commander": "^2.0.0"
+    "wordnet-db": "latest"
   },
   "devDependencies": {
-    "uubench": "git://github.com/moos/uubench.git",
+    "mini-bench": "^1.0.0",
     "chai": "*",
     "mocha": "*"
   },
-  "repository" : {
-    "type" : "git",
-    "url" : "git://github.com/moos/wordpos.git"
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/moos/wordpos.git"
   },
   "main": "./src/wordpos.js",
   "scripts": {
diff --git a/src/dataFile.js b/src/dataFile.js
index 63a870c..fa01208 100644
--- a/src/dataFile.js
+++ b/src/dataFile.js
@@ -1,24 +1,41 @@
+/*!
+ * dataFile.js
+ *
+ * Copyright (c) 2012-2016 mooster@42at.com
+ * https://github.com/moos/wordpos
+ *
+ * Portions: Copyright (c) 2011, Chris Umbel
+ *
+ * Released under MIT license
+ */
 
 var fs = require('fs'),
   path = require('path'),
   _ = require('underscore');
 
 
-// courtesy of natural.WordNet
-// TODO link
+/**
+ * parse a single data file line, returning data object
+ *
+ * @param line {string} - a single line from WordNet data file
+ * @returns {object}
+ *
+ * Credit for this routine to https://github.com/NaturalNode/natural
+ */
 function lineDataToJSON(line) {
   var data = line.split('| '),
     tokens = data[0].split(/\s+/),
     ptrs = [],
     wCnt = parseInt(tokens[3], 16),
-    synonyms = [];
+    synonyms = [],
+    i;
 
-  for(var i = 0; i < wCnt; i++) {
+  for(i = 0; i < wCnt; i++) {
     synonyms.push(tokens[4 + i * 2]);
   }
 
   var ptrOffset = (wCnt - 1) * 2 + 6;
-  for(var i = 0; i < parseInt(tokens[ptrOffset], 10); i++) {
+  for(i = 0; i < parseInt(tokens[ptrOffset], 10); i++) {
     ptrs.push({
       pointerSymbol: tokens[ptrOffset + 1 + i * 4],
       synsetOffset: parseInt(tokens[ptrOffset + 2 + i * 4], 10),
@@ -51,10 +68,15 @@ function lineDataToJSON(line) {
   };
 }
 
-
+/**
+ * read data file at location (bound to a data file).
+ * Reads nominal length and checks for EOL.  Continue reading until EOL.
+ *
+ * @param location {Number} - seek location
+ * @param callback {function} - callback function
+ */
 function readLocation(location, callback) {
   //console.log('## read location ', this.fileName, location);
-
   var
     file = this,
     str = '',
@@ -68,8 +90,6 @@ function readLocation(location, callback) {
       return;
     }
     //console.log('  read %d bytes at <%d>', count, location);
-    //console.log(str);
-
     callback(null, lineDataToJSON(str));
   });
 
@@ -77,10 +97,9 @@ function readLocation(location, callback) {
     fs.read(file.fd, buffer, 0, len, pos, function (err, count) {
       str += buffer.toString('ascii');
       var eol = str.indexOf('\n');
-
       //console.log('  -- read %d bytes at <%d>', count, pos, eol);
-
       if (eol === -1 && len < file.maxLineLength) {
+        // continue reading
         return readChunk(pos + count, cb);
       }
 
@@ -90,14 +109,19 @@ function readLocation(location, callback) {
   }
 }
 
+/**
+ * main lookup function
+ *
+ * @param record {object} - record to lookup, obtained from index.find()
+ * @param callback{function} (optional) - callback function
+ * @returns {Promise}
+ */
 function lookup(record, callback) {
   var results = [],
     self = this,
     offsets = record.synsetOffset;
 
   return new Promise(function(resolve, reject) {
-    //console.log('data lookup', record);
-
     offsets
       .map(function (offset) {
         return _.partial(readLocation.bind(self), offset);
@@ -109,7 +133,6 @@ function lookup(record, callback) {
 
     function done(lastResult) {
       closeFile();
-      //console.log('done promise -- ');
       if (lastResult instanceof Error) {
         callback && callback(lastResult, []);
         reject(lastResult);
@@ -129,7 +152,6 @@ function lookup(record, callback) {
       //console.log(' ... opening', self.filePath);
       self.fd = fs.openSync(self.filePath, 'r');
     }
-
     // ref count so we know when to close the main index file
     ++self.refcount;
     return Promise.resolve();
@@ -145,13 +167,17 @@ function lookup(record, callback) {
   }
 }
 
-
+/**
+ * turn ordinary function into a promising one!
+ *
+ * @param collect {Array} - used to collect results
+ * @returns {Function}
+ */
 function promisifyInto(collect) {
   return function(fn) {
     return function() {
       return new Promise(function (resolve, reject) {
-        fn(function (error, result) {               // Note callback signature!
-          //console.log('cb from get', arguments)
+        fn(function (error, result) {   // Note: callback signature!
           if (error) {
             reject(error);
           }
@@ -166,7 +192,13 @@ function promisifyInto(collect) {
 }
 
 
-
+/**
+ * DataFile class
+ *
+ * @param dictPath {string} - path to dict folder
+ * @param name {string} - POS name
+ * @constructor
+ */
 var DataFile = function(dictPath, name) {
   this.dictPath = dictPath;
   this.fileName = 'data.' + name;
@@ -177,13 +209,23 @@ var DataFile = function(dictPath, name) {
   this.refcount = 0;
 };
 
-// maximum read length at a time
+/**
+ * maximum read length at a time
+ * @type {Number}
+ */
 var MAX_SINGLE_READ_LENGTH = 512;
 
-//DataFile.prototype.get = get;
+/**
+ * lookup
+ */
 DataFile.prototype.lookup = lookup;
 
-// e.g.: wc -L data.adv as of v3.1
+
+/**
+ * maximum line length in each data file - used to optimize reads
+ *
+ * wc -L data.adv as of v3.1
+ */
 DataFile.MAX_LINE_LENGTH = {
   noun: 12972,
   verb: 7713,
@@ -191,4 +233,5 @@ DataFile.MAX_LINE_LENGTH = {
   adv: 638
 };
 
+
 module.exports = DataFile;
diff --git a/src/indexFile.js b/src/indexFile.js
index 1e7ed06..413e6d6 100644
--- a/src/indexFile.js
+++ b/src/indexFile.js
@@ -6,6 +6,8 @@
  * Copyright (c) 2012-2016 mooster@42at.com
  * https://github.com/moos/wordpos
  *
+ * Portions: Copyright (c) 2011, Chris Umbel
+ *
  * Released under MIT license
  */
 
@@ -16,6 +18,7 @@ var _ = require('underscore')._,
   piper = require('./piper'),
   KEY_LENGTH = 3;
 
+
 /**
  * load fast index bucket data
  *
@@ -112,7 +115,7 @@ function find(search, callback) {
   // pay the piper
   this.piper(task, readIndexForKey, args, context, collector);
 
-  function collector(key, index, search, callback, buffer){
+  function collector(_key, index, search, callback, buffer){
     var lines = buffer.toString().split('\n'),
       keys = lines.map(function(line){
         return line.substring(0,line.indexOf(' '));
@@ -136,21 +139,24 @@ function find(search, callback) {
  * @param word {string} - search word
  * @param callback {function} - callback function receives result
  * @returns none
+ *
+ * Credit for this routine to https://github.com/NaturalNode/natural
  */
 function lookup(word, callback) {
   var self = this;
 
   return new Promise(function(resolve, reject){
     self.find(word, function (record) {
-      var indexRecord = null;
+      var indexRecord = null,
+        i;
 
       if (record.status == 'hit') {
         var ptrs = [], offsets = [];
 
-        for (var i = 0; i < parseInt(record.tokens[3]); i++)
+        for (i = 0; i < parseInt(record.tokens[3]); i++)
           ptrs.push(record.tokens[i]);
 
-        for (var i = 0; i < parseInt(record.tokens[2]); i++)
+        for (i = 0; i < parseInt(record.tokens[2]); i++)
           offsets.push(parseInt(record.tokens[ptrs.length + 6 + i], 10));
 
         indexRecord = {
diff --git a/src/piper.js b/src/piper.js
index a5c18b5..4645d9e 100644
--- a/src/piper.js
+++ b/src/piper.js
@@ -12,7 +12,6 @@
 
 var _ = require('underscore')._,
   util = require('util'),
-  path = require('path'),
   fs = require('fs');
 
 /**
@@ -21,7 +20,7 @@ var _ = require('underscore')._,
  *
  * @param task {string} - task name unique to method!
  * @param method {function} - method to execute, gets (args, ... , callback)
- * @param args {array} - args to pass to method
+ * @param args {Array} - args to pass to method
  * @param context {object} - other params to remember and sent to callback
  * @param callback {function} - result callback
  */
diff --git a/src/rand.js b/src/rand.js
index ec29047..fd94cd3 100644
--- a/src/rand.js
+++ b/src/rand.js
@@ -36,10 +36,10 @@ function makeRandX(pos){
       callback = opts;
     }
 
-    index.rand(startsWith, count, function(record) {
+    return index.rand(startsWith, count, function (record) {
       args.push(record, startsWith);
       profile && args.push(new Date() - start);
-      callback.apply(null, args);
+      callback && callback.apply(null, args);
     });
   };
 }
@@ -50,6 +50,7 @@ function makeRandX(pos){
  * @param startsWith {string} - get random word(s) that start with this, or ''
  * @param num {number} - number of words to return
  * @param callback {function} - callback function, receives words array and startsWith
+ * @returns Promise
  */
 function rand(startsWith, num, callback){
   var self = this,
@@ -57,102 +58,115 @@ function rand(startsWith, num, callback){
     trie = this.fastIndex.trie,
     key, keys;
 
-  //console.log('-- ', startsWith, num, self.fastIndex.indexKeys.length);
-  if (startsWith){
-    key = startsWith.slice(0, KEY_LENGTH);
+  return new Promise(function(resolve, reject) {
 
-    /**
-     * if key is 'a' or 'ab' (<3 chars), search for ALL keys starting with that.
-     */
-    if (key.length < KEY_LENGTH) {
+    //console.log('-- ', startsWith, num, self.fastIndex.indexKeys.length);
+    if (startsWith) {
+      key = startsWith.slice(0, KEY_LENGTH);
 
-      // calc trie if haven't done so yet
-      if (!trie){
-        trie = new Trie();
-        trie.addStrings(self.fastIndex.indexKeys);
-        this.fastIndex.trie = trie;
-        //console.log(' +++ Trie calc ');
+      /**
+       * if key is 'a' or 'ab' (<3 chars), search for ALL keys starting with that.
+       */
+      if (key.length < KEY_LENGTH) {
+
+        // calc trie if haven't done so yet
+        if (!trie) {
+          trie = new Trie();
+          trie.addStrings(self.fastIndex.indexKeys);
+          self.fastIndex.trie = trie;
+          //console.log(' +++ Trie calc ');
+        }
+
+        try {
+          // trie throws if not found!!!!!
+          keys = trie.keysWithPrefix(startsWith);
+        } catch (e) {
+          keys = [];
+        }
+
+        // read all keys then select random word.
+        // May be large disk read!
+        key = keys[0];
+        nextKey = _.last(keys);
       }
 
-      try{
-        // trie throws if not found!!!!!
-        keys = trie.keysWithPrefix( startsWith );
-      } catch(e){
-        keys = [];
+      if (!key || !(key in self.fastIndex.offsets))  {
+        callback && callback([], startsWith);
+        resolve([]);
       }
 
-      // read all keys then select random word.
-      // May be large disk read!
-      key = keys[0];
-      nextKey = _.last(keys);
+    } else {
+      // no startWith given - random select among keys
+      keys = _.sample(self.fastIndex.indexKeys, num);
+
+      // if num > 1, run each key independently and collect results
+      if (num > 1) {
+        var results = [], ii = 0;
+        _(keys).each(function (startsWith) {
+          self.rand(startsWith, 1, function (result) {
+            results.push(result[0]);
+            if (++ii == num) {
+              callback && callback(results, '');
+              resolve(results);
+            }
+          });
+        });
+        return;
+      }
+      key = keys;
     }
 
-    if (!key || !(key in self.fastIndex.offsets)) return process.nextTick(function(){ callback([], startsWith) });
+    // prepare the piper
+    var args = [key, nextKey, self],
+      task = 'rand:' + key + nextKey,
+      context = [startsWith, num, callback]; // last arg MUST be callback
 
-  } else {
-    // no startWith given - random select among keys
-    keys = _.sample( this.fastIndex.indexKeys, num );
+    // pay the piper
+    self.piper(task, IndexFile.readIndexBetweenKeys, args, context, collector);
 
-    // if num > 1, run each key independently and collect results
-    if (num > 1){
-      var results = [], ii = 0;
-      _(keys).each(function(startsWith){
-        self.rand(startsWith, 1, function(result){
-          results.push(result[0]);
-          if (++ii == num) {
-            callback(results, '');
-          }
-        })
-      });
-      return;
-    }
-    key = keys;
-  }
-//  console.log(' using key', key, nextKey);
+    function collector(key, nextKey, index, startsWith, num, callback, buffer) {
+      var lines = buffer.toString().split('\n'),
+        matches = lines.map(function (line) {
+          return line.substring(0, line.indexOf(' '));
+        });
+      //console.log(' got lines for key ', key, lines.length);
 
-  // prepare the piper
-  var args = [key, nextKey, this],
-    task = 'rand:' + key + nextKey,
-    context = [startsWith, num, callback]; // last arg MUST be callback
+      // we got bunch of matches for key - now search within for startsWith
+      if (startsWith !== key) {
+        // binary search for startsWith within set of matches
+        var ind = _.sortedIndex(matches, startsWith);
+        if (ind >= lines.length || matches[ind].indexOf(startsWith) === -1) {
+          callback && callback([], startsWith);
+          resolve([]);
+          return;
+        }
 
-  // pay the piper
-  this.piper(task, IndexFile.readIndexBetweenKeys, args, context, collector);
-
-  function collector(key, nextKey, index, startsWith, num, callback, buffer){
-    var lines = buffer.toString().split('\n'),
-      matches = lines.map(function(line){
-        return line.substring(0,line.indexOf(' '));
-      });
-
-    //console.log(' got lines for key ', key, lines.length);
-
-    // we got bunch of matches for key - now search within for startsWith
-    if (startsWith !== key){
-
-      // binary search for startsWith within set of matches
-      var ind = _.sortedIndex(matches, startsWith);
-      if (ind >= lines.length || matches[ind].indexOf(startsWith) === -1){
-        return callback([], startsWith);
+        var trie = new Trie();
+        trie.addStrings(matches);
+        //console.log('Trie > ', trie.matchesWithPrefix( startsWith ));
+        matches = trie.keysWithPrefix(startsWith);
       }
 
-      // FIXME --- using Trie's new keysWithPrefix not yet pushed to npm.
-      // see https://github.com/NaturalNode/natural/commit/5fc86c42e41c1314bfc6a37384dd14acf5f4bb7b
-
-      var trie = new Trie();
-
-      trie.addStrings(matches);
-      //console.log('Trie > ', trie.matchesWithPrefix( startsWith ));
-
-      matches = trie.keysWithPrefix( startsWith );
+      var words = _.sample(matches, num);
+      callback && callback(words, startsWith);
+      resolve(words);
     }
 
-    var words = _.sample(matches, num);
-    callback(words, startsWith);
-  }
+  }); // Promise
 }
 
+// relative weight of each POS word count (DB 3.1 numbers)
+var POS_factor = {
+  Noun: 26,
+  Verb: 3,
+  Adjective: 5,
+  Adverb: 1,
+  Total: 37
+};
+
 /**
  * rand() - for all Index files
+ * @returns Promise
  */
 function randAll(opts, callback) {
   var
@@ -163,12 +177,7 @@ function randAll(opts, callback) {
     count = opts && opts.count || 1,
     args = [null, startsWith],
     parts = 'Noun Verb Adjective Adverb'.split(' '),
-    self = this,
-    done = function(){
-      profile && (args.push(new Date() - start));
-      args[0] = results;
-      callback.apply(null, args)
-    };
+    self = this;
 
   if (typeof opts === 'function') {
     callback = opts;
@@ -176,36 +185,45 @@ function randAll(opts, callback) {
     opts = _.clone(opts);
   }
 
-  // TODO -- or loop count times each time getting 1 from random part!!
-  // slower but more random.
 
-  // select at random a part to look at
-  var doParts = _.sample(parts, parts.length);
-  tryPart();
+  return new Promise(function(resolve, reject) {
+    // select at random a POS to look at
+    var doParts = _.sample(parts, parts.length);
+    tryPart();
 
-  function tryPart(){
-    var rand = 'rand' + doParts.pop();
-    self[ rand ](opts, partCallback);
-  }
+    function tryPart() {
+      var part = doParts.pop(),
+        rand = 'rand' + part,
+        factor = POS_factor[part],
+        weight = factor / POS_factor.Total;
 
-  function partCallback(result){
-    if (result) {
-      results = _.uniq(results.concat(result));  // make sure it's unique!
+      // pick count according to relative weight
+      opts.count = Math.ceil(count * weight * 1.1); // guard against dupes
+      self[rand](opts, partCallback);
     }
 
-    //console.log(result);
-    if (results.length < count && doParts.length) {
-      // reduce count for next part -- NO! may get duplicates
-      // opts.count = count - results.length;
-      return tryPart();
+    function partCallback(result) {
+      if (result) {
+        results = _.uniq(results.concat(result));  // make sure it's unique!
+      }
+
+      if (results.length < count && doParts.length) {
+        return tryPart();
+      }
+
+      // final random and trim excess
+      results = _.sample(results, count);
+      done();
     }
 
-    // trim excess
-    if (results.length > count) {
-      results.length = count;
+    function done() {
+      profile && (args.push(new Date() - start));
+      args[0] = results;
+      callback && callback.apply(null, args);
+      resolve(results);
     }
-    done();
-  }
+
+  }); // Promise
 }
 
 /**
diff --git a/src/wordpos.js b/src/wordpos.js
index 666c21a..29a286f 100644
--- a/src/wordpos.js
+++ b/src/wordpos.js
@@ -1,4 +1,4 @@
-/**
+/*!
 * wordpos.js
 *
 *    Node.js part-of-speech utilities using WordNet database.
@@ -149,11 +149,11 @@ function get(isFn) {
   };
 }
 
+// setImmediate executes callback AFTER promise handlers.
+// Without it, exceptions in callback may be caught by Promise.
 function nextTick(fn, args) {
   if (fn) {
-    setImmediate(function(){
-      fn.apply(null, args);
-    });
+    fn.apply(null, args);
   }
 }
 
@@ -216,7 +216,7 @@ var wordposProto = WordPOS.prototype;
  * lookup a word in all indexes
  *
  * @param word {string} - search word
- * @param callback {Functino} (optional) - callback with (results, word) signature
+ * @param callback {Function} (optional) - callback with (results, word) signature
  * @returns {Promise}
  */
 wordposProto.lookup = function(word, callback) {
@@ -362,7 +362,17 @@ wordposProto.getVerbs = get('isVerb');
 wordposProto.parse = prepText;
 
 
+/**
+ * access to WordNet DB
+ * @type {object}
+ */
 WordPOS.WNdb = WNdb;
+
+/**
+ * access to stopwords
+ * @type {Array}
+ */
 WordPOS.stopwords = stopwords;
 
+
 module.exports = WordPOS;
diff --git a/test.js b/test.js
deleted file mode 100644
index 45a6324..0000000
--- a/test.js
+++ /dev/null
@@ -1,40 +0,0 @@
-var
-    WordPOS       = require('./src/wordpos'),
-    wordpos       = new WordPOS({profile: true}),
-	getAllPOS = wordpos.getPOS
-	;
-
-
-console.log(1111,
-  wordpos.lookup('foot')
-  //wordpos.getPOS('was doing the work the ashtray closer Also known as inject and foldl, reduce boils down a list of values into a single value', console.log
-  .then(function(result){
-    console.log(' xxx - ', result)
-  })
-  .catch(function(result){
-    console.log(' error xxx - ', result)
-  }));
-
-//wordpos.rand({count: 3},console.log)
-
-return;
-
-
-//getAllPOS('se', console.log)
-wordpos.getPOS('se', console.log)
-
-
-
-
- a=wordpos.getPOS('se', function(res) {
-    console.log(1, res)
-    wordpos.getPOS('sea hey who work', function(res) {
-      console.log(2, res)
-      wordpos.getPOS('sear done work ', function(res) {
-        console.log(3, res)
-        console.log('all done');
-      });
-    });
-  });
-
-  console.log(a)
\ No newline at end of file
diff --git a/test/validate_test.js b/test/validate_test.js
index df42d61..f463d91 100644
--- a/test/validate_test.js
+++ b/test/validate_test.js
@@ -1,7 +1,7 @@
 /**
  * validate_test.js
  *
- * Run validate on all four main index files
+ *     Run validate on all four main index files
  *
  * Copyright (c) 2012-2016 mooster@42at.com
  * https://github.com/moos/wordpos
diff --git a/test/wordpos_test.js b/test/wordpos_test.js
index b349f83..9eb1fce 100644
--- a/test/wordpos_test.js
+++ b/test/wordpos_test.js
@@ -1,11 +1,11 @@
 /**
- * wordpos_spec.js
+ * wordpos_test.js
  *
- *     test file for main wordpos functionality
+ *   test file for main wordpos functionality
  *
  * Usage:
  *   npm install mocha -g
- *   mocha wordpos_spec.js --verbose
+ *   mocha wordpos_test.js
  *
  *   or
  *
@@ -388,4 +388,29 @@ describe('Promise pattern', function() {
       assert.equal(result, true);
     });
   });
+
+  it('rand()', function () {
+    return wordpos.rand({count: 5}).then(function (result) {
+      assert.equal(result.length, 5);
+    });
+  });
+
+  it('randNoun()', function () {
+    return wordpos.randNoun().then(function (result) {
+      assert.equal(result.length, 1);
+    });
+  });
+
+  it('randNoun({count: 3})', function () {
+    return wordpos.randNoun({count: 3}).then(function (result) {
+      assert.equal(result.length, 3);
+    });
+  });
+
+  it('randNoun({startsWith: "foo"})', function () {
+    return wordpos.randNoun({startsWith: 'foo'}).then(function (result) {
+      assert.equal(result.length, 1);
+      assert.equal(result[0].indexOf('foo'), 0);
+    });
+  });
 });
\ No newline at end of file
diff --git a/tools/stat.js b/tools/stat.js
index 77c0922..e045ae7 100644
--- a/tools/stat.js
+++ b/tools/stat.js
@@ -1,7 +1,7 @@
 /**
  * stat.js
  *
- * generate fast index for WordNet index files
+ *     generate fast index for WordNet index files
  *
  * Usage:
  *    node stat [--no-stats] index.adv ...
@@ -40,7 +40,7 @@
  *      read index file between the two offsets
  *  	binary search read data O(log avg)
  *
- * Copyright (c) 2012 mooster@42at.com
+ * Copyright (c) 2012-2016 mooster@42at.com
  * https://github.com/moos/wordpos
  *
  * Released under MIT license
@@ -48,7 +48,7 @@
 var
   WNdb = require('../src/wordpos').WNdb,
   util = require('util'),
-  BufferedReader = require ("./buffered-reader"),
+  BufferedReader = require ('./buffered-reader'),
   _ = require('underscore')._,
   fs = require('fs'),
   path = require('path'),
diff --git a/tools/validate.js b/tools/validate.js
index e9fa3f0..f29cc8c 100644
--- a/tools/validate.js
+++ b/tools/validate.js
@@ -1,12 +1,12 @@
 /**
  * validate.js
  *
- * read each index.<pos> file, and look up using wordpos and confirm find all words
+ *    read each index.<pos> file, and look up using wordpos and confirm find all words
  *
  * Usage:
  *    node validate index.adv
  *
- * Copyright (c) 2012 mooster@42at.com
+ * Copyright (c) 2012-2016 mooster@42at.com
  * https://github.com/moos/wordpos
  *
  * Released under MIT license