diff --git a/server.go b/server.go
index 753b131..e93dc94 100644
--- a/server.go
+++ b/server.go
@@ -136,7 +136,11 @@ type event struct {
 //
 //------------------------------------------------------------------------------
 
-// Creates a new server with a log at the given path.
+// Creates a new server with a log at the given path. transporter must
+// not be nil. stateMachine can be nil if snapshotting and log
+// compaction is to be disabled. context can be anything (including nil)
+// and is not used by the raft package except returned by
+// Server.Context(). connectionString can be anything.
 func NewServer(name string, path string, transporter Transporter, stateMachine StateMachine, context interface{}, connectionString string) (Server, error) {
 	if name == "" {
 		return nil, errors.New("raft.Server: Name cannot be blank")
diff --git a/statemachine.go b/statemachine.go
index e59036c..a0a22e8 100644
--- a/statemachine.go
+++ b/statemachine.go
@@ -7,7 +7,8 @@ package raft
 //------------------------------------------------------------------------------
 
 // StateMachine is the interface for allowing the host application to save and
-// recovery the state machine
+// recovery the state machine. This makes it possible to make snapshots
+// and compact the log.
 type StateMachine interface {
 	Save() ([]byte, error)
 	Recovery([]byte) error