IN can be a tricky field because of how names are formatted.  A mistake people sometimes make is they use parentheses and not quotes in their inventor searches.  For example:

• ANO:(Apple Inc) AND IN:"Smith, Michael" returns 20 US patents
• ANO:(Apple Inc) AND IN:(Smith, Michael) returns 23 US patents.  In this case, Michael and Smith must be in the inventor fields but not necessarily next to each other.  So there could be a Michael Jones and a John Smith that were both in the inventor fields, and this search would return the document.  Therefore, the search over-attributes Michael Smith's patent activity while at Apple.

Another technique is to use a proximity search in the IN field to ensure you capture mistakes that may have been made by entering a name in reverse order.  It occasionally happens with Chinese names, because they may be accidentally listed in reverse.

• IN:Zhang NEAR1 Zhijun  -->  This query finds instance of both strings "Zhang Zhijun" and "Zhijun Zhang."
• IN:Steve NEAR2 Jobs  -->  Finds instances of name no matter where the middle initial is placed.

Remember that the NEAR and ADJ syntax are not the same thing.  ADJ1 would not have returned "Zhang Zhijun" and "Zhijun Zhang."