First of all, high confidence results are displayed by the Microsoft.Office.Server.Search.WebControls.HighConfidenceWebPart (Microsoft.Office.Server.Search assembly). On the standard search result page (results.aspx) there are two instances of this web part. One is Search High Confidence Results, the other is Search Best Bets. If you check the properties of the HighConfidenceWebPart either by modifying the shared web part, or by using Reflector, you can see that this web part can display keyword matches with best bets and the mysterious high confidence results. By default the Search High Confidence Results web part instance is configured to display the high confidence results and the Search Best Bets web part instance is configured to display keywords and best bets (as one can guess from their name).

The SDK contains information about that when the Enterprise Search returns the results there is a HighConfidenceResults table that is “The result set containing high-confidence results”. Well, it is not very descriptive, is it?

Let’s see the formatting XSL for the HighConfidenceWebPart. You can check it in the XSL Editor in the Data View Properties section of the tool part. Fortunately, there is a template for the HighConfidenceResults, displayed below:

<xsl:template match="All_Results/HighConfidenceResults/Result"> 
 <xsl:if test="$DisplayHC = 'True' and $IsFirstPage = 'True'" >
  <xsl:variable name="prefix">IMNRC('</xsl:variable>
  <xsl:variable name="suffix">')</xsl:variable>
  <xsl:variable name="url" select="url"/>
  <xsl:variable name="id" select="id"/>
  <xsl:variable name="pictureurl" select="highconfidenceimageurl"/>
  <xsl:variable name="jobtitle" select="highconfidencedisplayproperty1"/>
  <xsl:variable name="workphone" select="highconfidencedisplayproperty2"/>
  <xsl:variable name="department" select="highconfidencedisplayproperty3"/>
  <xsl:variable name="officenumber" select="highconfidencedisplayproperty4"/>
  <xsl:variable name="preferredname" select="highconfidencedisplayproperty5"/>
  <xsl:variable name="aboutme" select="highconfidencedisplayproperty8"/>
  <xsl:variable name="responsibility" select="highconfidencedisplayproperty9"/>
  <xsl:variable name="skills" select="highconfidencedisplayproperty10"/>
  <xsl:variable name="workemail" select="highconfidencedisplayproperty11"/>

You can see, that all of the properties are related to persons. I found that if you search for a person specifying the full name, and there is match, then it is displayed as a high confidence result. In the web part properties you can specify if the title, image, description and other properties should be displayed for a high confidence match. There is a ResultsPerTypeLimit property (“Maximum matches per High Confidence type ”) that similar to the BestBetsLimit property (“Best Bets limit ” on the user interface). Based on my experience, the BestBetsLimit works as expected but the ResultsPerTypeLimit seems to have no effect on the displayed results. Checking the default formatting XSL shows that the BestBetsLimit property is used (BBLimit parameter), but the ResultsPerTypeLimit is not used, although it is declared as an XSL parameter with the same name.

You should include the following condition in the HighConfidenceResults template (see above) after checking the "$DisplayHC = 'True' and $IsFirstPage = 'True'" condition:

<xsl:if test="position() &lt;= $ ResultsPerTypeLimit " >