diff --git a/nltk_trainer/__init__.py b/nltk_trainer/__init__.py
index 448bda2..d66e209 100644
--- a/nltk_trainer/__init__.py
+++ b/nltk_trainer/__init__.py
@@ -38,15 +38,20 @@ def load_corpus_reader(corpus, reader=None, fileids=None, **kwargs):
 			raise ValueError('you must specify a corpus reader')
 		
 		if not fileids:
-			raise ValueError('you must specify the corpus fileids')
+			fileids = '.*'
 		
-		if os.path.isdir(corpus):
-			root = corpus
-		else:
+		root = os.path.expanduser(corpus)
+		
+		if not os.path.isdir(root):
+			if not corpus.startswith('corpora/'):
+				path = 'corpora/%s' % corpus
+			else:
+				path = corpus
+			
 			try:
-				root = nltk.data.find(corpus)
+				root = nltk.data.find(path)
 			except LookupError:
-				raise ValueError('cannot find corpus path %s' % corpus)
+				raise ValueError('cannot find corpus path for %s' % corpus)
 		
 		reader_cls = import_attr(reader)
 		real_corpus = reader_cls(root, fileids, **kwargs)
diff --git a/train_chunker.py b/train_chunker.py
index 778c202..ed0718e 100755
--- a/train_chunker.py
+++ b/train_chunker.py
@@ -69,14 +69,10 @@
 ## corpus reader ##
 ###################
 
-chunked_corpus = load_corpus_reader(args.corpus, reader=args.reader, fileids=args.fileids)
-
-if not chunked_corpus:
-	raise ValueError('%s is an unknown corpus')
-
 if args.trace:
-	print 'loading nltk.corpus.%s' % args.corpus
-# trigger loading so it has its true class
+	print 'loading %s' % args.corpus
+
+chunked_corpus = load_corpus_reader(args.corpus, reader=args.reader, fileids=args.fileids)
 chunked_corpus.fileids()
 fileids = args.fileids
 kwargs = {}
diff --git a/train_classifier.py b/train_classifier.py
index 5711c42..697aae2 100755
--- a/train_classifier.py
+++ b/train_classifier.py
@@ -10,7 +10,7 @@
 from nltk.metrics import BigramAssocMeasures, f_measure, masi_distance, precision, recall
 from nltk.probability import FreqDist, ConditionalFreqDist
 from nltk.util import ngrams
-from nltk_trainer import dump_object, import_attr
+from nltk_trainer import dump_object, import_attr, load_corpus_reader
 from nltk_trainer.classification import corpus, scoring
 from nltk_trainer.classification.featx import bag_of_words, bag_of_words_in_set, train_test_feats
 from nltk_trainer.classification.multi import MultiBinaryClassifier
@@ -37,9 +37,9 @@
 	help='number of most informative features to show, works for all algorithms except DecisionTree')
 
 corpus_group = parser.add_argument_group('Training Corpus')
-corpus_group.add_argument('--reader', choices=('plaintext', 'tagged'),
-	default='plaintext',
-	help='specify categorized plaintext or part-of-speech tagged corpus')
+corpus_group.add_argument('--reader',
+	default='nltk.corpus.reader.CategorizedPlaintextCorpusReader',
+	help='Full module path to a corpus reader class, such as %(default)s')
 corpus_group.add_argument('--cat_pattern', default='(.+)/.+',
 	help='''A regular expression pattern to identify categories based on file paths.
 	If cat_file is also given, this pattern is used to identify corpus file ids.
@@ -129,11 +129,6 @@
 ## corpus reader ##
 ###################
 
-reader_class = {
-	'plaintext': CategorizedPlaintextCorpusReader,
-	'tagged': CategorizedTaggedCorpusReader
-}
-
 reader_args = []
 reader_kwargs = {}
 
@@ -160,8 +155,15 @@
 if args.para_block_reader:
 	reader_kwargs['para_block_reader'] = import_attr(args.para_block_reader)
 
-categorized_corpus = LazyCorpusLoader(args.corpus, reader_class[args.reader],
+if args.trace:
+	print 'loading %s' % args.corpus
+
+categorized_corpus = load_corpus_reader(args.corpus, args.reader,
 	*reader_args, **reader_kwargs)
+
+if not hasattr(categorized_corpus, 'categories'):
+	raise ValueError('%s is does not have categories for classification')
+
 labels = categorized_corpus.categories()
 nlabels = len(labels)
 
@@ -291,9 +293,6 @@ def norm_words(words):
 	scoring.cross_fold(train_feats, trainf, accuracy, folds=args.cross_fold,
 		trace=args.trace, metrics=not args.no_eval, informative=args.show_most_informative)
 else:
-	if args.trace:
-		print 'training %s classifier' % args.classifier
-	
 	classifier = trainf(train_feats)
 
 ################
diff --git a/train_tagger.py b/train_tagger.py
index 3666a78..f7e74c7 100755
--- a/train_tagger.py
+++ b/train_tagger.py
@@ -109,16 +109,10 @@
 ## corpus reader ##
 ###################
 
-tagged_corpus = load_corpus_reader(args.corpus, reader=args.reader, fileids=args.fileids)
-
-if not tagged_corpus:
-	raise ValueError('%s is an unknown corpus')
-
 if args.trace:
-	print 'loading nltk.corpus.%s' % args.corpus
-# trigger loading so it has its true class
-tagged_corpus.fileids()
-# fileid is used for corpus naming, if it exists
+	print 'loading %s' % args.corpus
+
+tagged_corpus = load_corpus_reader(args.corpus, reader=args.reader, fileids=args.fileids)
 fileids = args.fileids
 kwargs = {}
 
@@ -130,7 +124,7 @@
 	raise ValueError('%s does not support simplify_tags' % args.corpus)
 
 if isinstance(tagged_corpus, SwitchboardCorpusReader):
-	if args.fileids:
+	if fileids:
 		raise ValueError('fileids cannot be used with switchboard')
 	
 	tagged_sents = list(itertools.chain(*[[list(s) for s in d if s] for d in tagged_corpus.tagged_discourses(**kwargs)]))