Exploration & description/Livestock species owned

Note that in such situations where there are suspicions about the authenticity of certain data values and having first checked the raw data to see whether there may have been a mistake in data entry, any changes to the data file should always be documented and kept in what is sometimes referred to as an 'Audit trail' file. For the purpose of this case study a note has been made at the foot of CS11Doc1 - see below.

GenStat has a facility that defines values to be temporarily missing (Spread → Column → Temporary missing values...) but retains the value in the file. This can be useful during exploratory analysis to see what impact omitting a value may have on the analysis and saves preliminary editing of a data file and delays any necessity of documenting any alteration to the data.

Edited data

Values in the following records in CS11Data1 have been replaced by missing values: