Re: Problems with Zero Abundance observations
A customer has reported problems with zero abundance observations in Recorder 2002 but testing has also revealed problems in Recorder 6.
I input some single observations using Data Entry – Enter a species record in Recorder 2002 version 2.3.7.8. The ZERO_ABUNDANCE indicators in the TAXON_OCCURRENCE table were set to Yes or No correctly and the observations were included/excluded from reports produced using the Report Wizard as expected. The only problem was that each observation was listed in the filter result 4 times. I expected them to appear twice because each had 2 sets of measurement data but not 4 times.
I then input some observations using one of the customers recording cards, i.e.
Data Entry – Enter Species for a place – Level_III_Adult_Amphibian_Survey_Form_recordtype.
In this case the ZERO_ABUNDANCE indicators in the TAXON_OCCURRENCE table were set to No even when all the abundance measurement data for an observation was entered as 0 (zero). Thus the observations were all included in reports produced using the Report Wizard regardless of whether ‘Exclude Zero Abundance Data’ was ticked or not. Observations that had 3 sets of measurement data were listed 9 times. For one of the zero abundance observations, I used Access to change the ZERO_ABUNDANCE indicator in the TAXON_OCCURRENCE to Yes. It was then excluded from a report done using the Report Wizard when ‘Exclude Zero Abundance Data’ was ticked. This problem did not occur when the system supplied measurement unit ‘Count’ was used. It only occurred when using a user added measurement unit with a Data Type of Text.
These tests show that in Recorder 2002, the ZERO_ABUNDANCE indicator is not being set correctly for zero abundance observations when the measurement unit has a Data Type of Text.
I have also done some testing in Recorder 6 version 6.9.3.102 to see if there are similar problems there, the logic being that if there are, hopefully, JNCC will be able to get them fixed before this customer moves over to it. There are problems in Recorder 6 with the setting of the ZERO_ABUNDANCE indicator but they aren’t the same as in Recorder 2002. The ZERO_ABUNDANCE indicator was set correctly for the observations I entered using a recording card but not for those entered using Data Entry – Enter a species record. In this case the indicator was set to 0 (No), even when the abundance measurement data was 0, and the observations were included in the filter result when the tick was left on ‘Exclude Zero Abundance Data’ in the Report Wizard. Recorder 6 doesn’t report on abundance data in the same way as Recorder 2002 and I am pleased to say that, unlike Recorder 2002, individual taxon occurrences are only listed once. The trouble is that you have to select each measurement qualifier you want included in the report. This will be a nuisance if you are reporting on unfamiliar data and you don’t know what qualifiers have been used for entering it. It would be nice if there was an option to select all qualifiers used.
As with Recorder 2002, I found that if the ZERO_ABUNDANCE indicator was corrected in nbndata.mdb (the Access database that links to the SQL Server database) then the observations were excluded/included from the filter result correctly.
Given my findings, it is possible that any user’s system will contain observations where the ZERO_ABUNDANCE indicators are not set correctly. Hence, as well as needing the bugs fixed, users will need some code to correct zero abundance observations that have already been entered. Sarah (JNCC), could you please investigate this and let us know what can be done in Recorder 2002/Recorder 6. Please note that I have done enough testing to provide the information above but there could be other circumstances under which the ZERO_ABUNDANCE indicators are not set correctly.
E-mail: s.rankin@btinternet.com
Telephone: 01491 578633
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