diff --git a/README.md b/README.md
index 1762fc3..90fb183 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # average
 
 Calculate statistics of a sequence iteratively in a single pass, using
-constant memory and avoiding numerical problems. The calculations can be
+constant space and avoiding numerical problems. The calculations can be
 easily parallelized by using `merge`.
 
 [![Documentation Status]][docs.rs]
@@ -25,4 +25,4 @@ easily parallelized by using `merge`.
 ## Related Projects
 
 * [`quantiles`](https://crates.io/crates/quantiles):
-  Provides quantile estimates with bounded error but using variable memory.
+  Provides quantile estimates with bounded error but using growing space.
diff --git a/src/quantile.rs b/src/quantile.rs
index 0b6e52f..1e23f4f 100644
--- a/src/quantile.rs
+++ b/src/quantile.rs
@@ -9,7 +9,7 @@ use super::Estimate;
 /// Estimate the p-quantile of a sequence of numbers ("population").
 ///
 /// The algorithm uses constant space but does not provide any upper bound on
-/// the error. For algorithms that use variable space with bounded error, see
+/// the error. For algorithms that use growing space with bounded error, see
 /// the [`quantiles`](https://crates.io/crates/quantiles) crate. They are
 /// recommended over this algorithm for small samples.
 // This uses the P² algorithm introduced here: