diff --git a/doc/db_dump.php b/doc/db_dump.php
index 332eb18c4c..b40a5d24ec 100644
--- a/doc/db_dump.php
+++ b/doc/db_dump.php
@@ -1,42 +1,11 @@
 <?php
 require_once("docutil.php");
-page_head("Downloadable statistics data");
+page_head("File-based project statistics data");
 echo "
 
 <p>
-BOINC projects can export <b>statistics data</b>
-describing teams, users and hosts.
-This data can be used for various purposes:
-<ul>
-<li> To produce
-web sites that show statistics and leaderboards
-for one or more BOINC projects.
-Examples are listed at <a href=stats_sites.php>here</a>.
-
-<li> To produce dynamically-generated images
-(typically used as message-board signatures)
-that show user and/or team credit, possible across projects.
-Examples are listed at <a href=stats_sites.php>here</a>.
-
-<li> To produce downloadable XML files that
-summarize cross-project statistics.
-We're trying to <a href=stats_xml.php> standardize the XML format</a>.
-
-<li> To produce web RPC interfaces to XML summaries of
-individual user or team statistics.
-We're trying to <a href=stats_xml.php> standardize the XML format</a>.
-Examples are here:
-<a href=http://www.boinc.dk/index.php?page=download_stats_xml>
-http://www.boinc.dk/index.php?page=download_stats_xml</a> and
-<a href=http://www.boincstats.com/xml/xml_user_example.php>http://www.boincstats.com/xml/xml_user_example.php</a>.
-
-</ul>
-
-<p>
-Statistics data is exported in XML-format files.
-<p>
+Projects export statistics data in XML-format files.
 Most projects regenerate the files every 24 hours.
-<p>
 These files are contained in a download directory,
 linked to from the project's web site
 (generally X/stats/, where X is the project URL).
diff --git a/doc/stats.odg b/doc/stats.odg
index 42e2b2e34b..8b8a6c3f02 100644
Binary files a/doc/stats.odg and b/doc/stats.odg differ
diff --git a/doc/stats.php b/doc/stats.php
index cc7a599189..7916726ec1 100644
--- a/doc/stats.php
+++ b/doc/stats.php
@@ -4,8 +4,88 @@ require_once("docutil.php");
 
 page_head("Statistics data");
 echo "
-Stati
+<b>Statistics data</b> is the number of
+<a href=credit.php>Cobblestones</a> (credit units)
+granted to hosts, participants and teams by the
+various BOINC projects.
+This data can be used for various purposes, such as:
+<ul>
+<li> Producing
+web sites that show statistics and leaderboards
+for one or more BOINC projects.
+Examples are listed at <a href=stats_sites.php>here</a>.
+
+<li> Producing dynamically-generated images
+(typically used as message-board signatures)
+that show user and/or team credit, possible across projects.
+Examples are listed at <a href=stats_sites.php>here</a>.
+
+<li> Producing displays of current credit on
+cell phones and PDAs.
+</ul>
+
+<p>
+BOINC provides a flexible architecture for distributing
+statistics data, with the intent of enabling new uses of this data.
+<p>
 <img src=stats.png>
+<p>
+<center><b>The BOINC statistics data architecture</b></center>
+
+<h2>Project data</h2>
+<p>
+Each BOINC project provides data in two forms:
+<ul>
+<li> As
+<a href=db_dump.php>a set of downloadable files</a>
+(in a compressed XML format)
+that contain the project's complete current statistics.
+These files are typically updated once every 24 hours.
+<li> As
+<a href=rpc.php>a set of Web RPCs</a>
+that return an XML-format description of a given
+participant's credit,
+based on that participant's database ID.
+</ul>
+
+<p>
+Applications should access these data sources
+as infrequently as possible,
+to avoid imposing unnecessary load on project servers.
+For example, a Web RPCs to get a particular participant's data
+should made at most once per hour.
+
+
+<h2>Aggregate data</h2>
+<p>
+A <b>data aggregator</b> is a service that collects XML files
+from several projects,
+and computes the totals for participants and hosts
+(based on <a href=foo>cross-project IDs</a>)
+across these projects.
+This aggregate data is then exported in two ways:
+<ul>
+<li> As
+<a href=stats_xml.php>a set of downloadable files</a>
+(in a compressed XML format).
+<li> As
+<a href=stats_xml.php#rpc>a set of Web RPCs</a>
+that return an XML-format description of a given participant
+or host's credit,
+based on the cross-project ID.
+</ul>
+<p>
+Examples are here:
+<a href=http://www.boinc.dk/index.php?page=download_stats_xml>
+http://www.boinc.dk/index.php?page=download_stats_xml</a> and
+<a href=http://www.boincstats.com/xml/xml_user_example.php>http://www.boincstats.com/xml/xml_user_example.php</a>.
+
+<p>
+Application developers are encouraged to concentrate
+on aggregate rather than per-project data.
+This will encourage participants to join multiple projects,
+and will make it possible for new projects to quickly get
+many participants.
 ";
 
 page_tail();