Filtering in the report on a particular column containing empty values will not provide expected results without using "IS NOT EMPTY" or "IS EMPTY" condition.SummaryFor Example: Let us assume there are 5 records.Now only 2 records having values for Assignment group (hardware and software).where rest of the records having empty values for Assignment group column.Now try to filter the report using the condition as belowCondition: "Assignment group" ->"IS NOT" -> "Hardware"Actual Result: 1Expected Result: 4 Because here filter will Apply on the non-empty values for matching condition but not on the Empty values.So to avoid this, Please use another filter along with that as below. Condition : "Assignment Group" ->"IS EMPTY" You can try using different ways to match your requirement.But "IS EMPTY" or "IS NOT EMPTY" is required to use if there are any empty values on the filtering column.Related LinksFor more information,Please check the related case #CS4688109 which contain detailed information.