diff --git a/collects/scribblings/reference/concurrency.scrbl b/collects/scribblings/reference/concurrency.scrbl
index d9098d684f..e0a9ca6729 100644
--- a/collects/scribblings/reference/concurrency.scrbl
+++ b/collects/scribblings/reference/concurrency.scrbl
@@ -3,11 +3,9 @@
 
 @title[#:tag "concurrency" #:style 'toc]{Concurrency}
 
-PLT Scheme supports multiple threads of control within a
-program. Threads run concurrently, in the sense that one thread can
-preempt another without its cooperation, but threads currently all run
-on the same processor (i.e., the same underlying OS process and
-thread).
+PLT Scheme supports multiple threads of control within a program,
+thread-local storage, some primitive synchronization mechanisms, and a
+framework for composing synchronization abstractions.
 
 @local-table-of-contents[]
 
diff --git a/collects/scribblings/reference/eval-model.scrbl b/collects/scribblings/reference/eval-model.scrbl
index b9303df996..c646ebf7f4 100644
--- a/collects/scribblings/reference/eval-model.scrbl
+++ b/collects/scribblings/reference/eval-model.scrbl
@@ -650,8 +650,12 @@ escape-continuation aborts can cross continuation barriers.
 @;------------------------------------------------------------------------
 @section[#:tag "thread-model"]{Threads}
 
-Scheme supports multiple, pre-emptive @deftech{threads} of
-evaluation. Threads are created explicitly by functions such as @scheme[thread]. 
+Scheme supports multiple @deftech{threads} of evaluation.  Threads run
+concurrently, in the sense that one thread can preempt another without
+its cooperation, but threads currently all run on the same processor
+(i.e., the same underlying OS process and thread).
+
+Threads are created explicitly by functions such as @scheme[thread]. 
 In terms of the evaluation model, each step in evaluation actually consists of multiple concurrent
 expressions, up to one per thread, rather than a single expression. The expressions all
 share the same objects and top-level variables, so that they can