<sect1 id='about-statistics'>
<title>About statistics</title>
<para>Some exercises will show some statistics for different periods of time:
<emphasis>Session</emphasis>, <emphasis>Today</emphasis>, <emphasis>Last 7
days</emphasis> and <emphasis>Total</emphasis>. The program uses two
different kind of tables.</para>

<informalfigure>
  <screenshot>
    <mediaobject>
      <imageobject>
        <imagedata fileref="figures/statistics.png" format="PNG"/>
      </imageobject>
      <textobject>
        <phrase>Screenshot of the percentages table of a statistics page.</phrase>
      </textobject>
    </mediaobject>
  </screenshot>
</informalfigure>
<para>The first table, as shown in the screenshot above, have one
row for each question in the lesson file. 
<emphasis>Percent</emphasis> is the percentage of the times the question have
been answered correctly. <emphasis>Count</emphasis> is the number of times
the question have been asked.
</para>

<para>In the second type of table, the columns have the same labels as the rows,
but the labels are not displayed because it will make the table
too wide. So in the screenshot above, column 1 should have the label
<emphasis>m3↑</emphasis> and column 2 <emphasis>M3↑</emphasis>.

For the questions identified by the label of each row, each
column tell how many times the user have answered the different possible
answers. The bold number is the number of times the correct answer have
been give.</para>

</sect1>
