diff --git a/src/data.jl b/src/data.jl
index 87e87b94..be5497b6 100644
--- a/src/data.jl
+++ b/src/data.jl
@@ -1,7 +1,23 @@
 export onehot, onecold, chunk, partition, batches, sequences
 
+"""
+    onehot('b', ['a', 'b', 'c', 'd']) => [false, true, false, false]
+
+    onehot(Float32, 'c', ['a', 'b', 'c', 'd']) => [0., 0., 1., 0.]
+
+Produce a one-hot-encoded version of an item, given a list of possible values
+for the item.
+"""
 onehot(T::Type, label, labels) = T[i == label for i in labels]
 onehot(label, labels) = onehot(Int, label, labels)
+
+"""
+    onecold([0.0, 1.0, 0.0, ...],
+            ['a', 'b', 'c', ...]) => 'b'
+
+The inverse of `onehot`; takes an output prediction vector and a list of
+possible values, and produces the appropriate value.
+"""
 onecold(pred, labels = 1:length(pred)) = labels[findfirst(pred, maximum(pred))]
 
 using Iterators