anchor.diff:  search system.
   
   The challenge for search engineers is to tweak this translation process from 
  -user entries to a concrete query in such a way, that the search results contain 
  -the most relevant information with respect to the users information need. This 
  +user entries to a concrete query, in such a way that the search results contain 
  +the most relevant information with respect to the user's information need. This 
   can only be done if the search result quality is evaluated constantly across a 
   representative test suite of typical user queries, so that improvements in the 
  -rankings for one particular query doesn't negatively effect the ranking for 
  +rankings for one particular query don't negatively affect the ranking for 
   other types of queries.
   
  -In order to get started with search quality evaluation, three basic things are 
  -needed:
  +In order to get started with search quality evaluation, you need three basic
  +things:
   
   . A collection of documents you want to evaluate your query performance against, 
     usually one or more indices.
   . A collection of typical search requests that users enter into your system.
  -. A set of document ratings that judge the documents relevance with respect to a 
  -  search request.
  +. A set of document ratings that represent the documents' relevance with respect
  +  to a search request.
     
   It is important to note that one set of document ratings is needed per test 
   query, and that the relevance judgements are based on the information need of 
  
positive.code: 
  The ranking evaluation API provides a convenient way to use this information in 
  a ranking evaluation request to calculate different search evaluation metrics. 
  This gives a first estimation of your overall search quality and give you a 
  measurement to optimize against when fine-tuning various aspect of the query 
  generation in your application.
  
  
negative.code: [cols="<,<",options="header",]
  |=======================================================================
  |Parameter |Description
  | `maximum_relevance` | Mandatory parameter. The highest relevance grade used in the user-supplied
  relevance judgments.
  |`k` | sets the maximum number of documents retrieved per query. This value will act in place of the usual `size` parameter
  in the query. Defaults to 10.
  