This is a question about double data entry in EpiData :

We commonly use EpiData to do double data entry. We use Tools > Prepare Double Entry Verification and select the field ID for matching records.

When we open the *_dbl file for data entry, a box usually opens stating 'double data entry verification mode / data compared with *.rec / compared by Field ID'.

What does it mean when that box does not open ? Are we simply entering records into the _dbl file without comparing fields from the *.rec file ?

Recently we have experienced the box opening *and* the box NOT opening when selecting the same _dbl file for data entry. How can we know for certain that all records in the _dbl file have been verified - even when the box does not open.

Thanks in advance.