Hi Rodolfo, I am not sure if I understand you correctly so I will just try to explain how it works: With avg operator, you can get a valid "disaggregated" data value for period "within" the data collection frequency. So if you collect population with a yearly frequency for a data element with the avg operator, then you can also ask for the monthly value for a month in that year. In that case, the values will be the same - sort of a "standing value" for that period. If you have a value of e.g. 1000 people for the year, then the value for the month will also be 1000. This is just the nature of the data - if you have a population of 1000 for the year, then we must assume that the population for a month is also 1000.
We do not allow "average within a period" or disaggregations for data element which naturally sums across time. As an example, if you collect cases of some disease at a quarterly frequency, we don't allow retrieving the value for a month within that quarter simply using the average. The reason is that it would not be valid statistics - we have no evidence that not all cases happened in the last month of the quarter, etc. regards, Lars On Mon, May 19, 2014 at 1:48 PM, Rodolfo Melia <rme...@knowming.com> wrote: > Hi Lars - thanks for the quick reply. > > I though AVG was valid within the same data-collection period as well as > across time. If this is the case, how do you calculate an average within > the same data collection period? AN indicator that divides the DE that has > the answer between valid answers? Normally that will be completed forms, > but such variable is not available as a denominator. We will have to use a > different Data Element that count valid answers. Last, such indicator will > make sense within the same period, but not across periods, as it will give > you an incorrect value, I think. > > Are you sure that AVG only makes sense across-time? Wouldn't be better to > also use the same logic within the same period? What's the rationale? If > there anyone out not wanting AVG to be calculated on the same data > collection period as across periods? > > R > > *Rodolfo Meliá* > *Principal | *rme...@knowming.com > Skype: rod.melia | +44 777 576 4090 | +1 708 872 7636 > www.knowming.com > > > On Mon, May 19, 2014 at 12:05 PM, Lars Helge Øverland <larshe...@gmail.com > > wrote: > >> Hi James, >> >> the "aggregation operator" refers to the time dimension - data will be >> averaged through time but still summed in the org unit hierarchy dimension. >> We could make this clearer in the system I guess. >> >> regards, >> >> Lars >> >> >> >> On Mon, May 19, 2014 at 12:55 PM, James Chang <jamesbch...@gmail.com>wrote: >> >>> Hi, >>> >>> On DHIS demo site, http://apps.dhis2.org/demo, >>> 'Average' aggregation operator seem to do 'Sum' instead. >>> >>> I didn't do any data entry or ran Analytics, but only looking at the >>> current data, 'Total Population' in 'Ngelehun CHC' and 'Njandama MCHP' seem >>> to sum on 'Badjia' even though the 'Total Population' is set to 'Average' >>> for Aggregation operator. >>> >>> See the attached images. >>> >>> >>> _______________________________________________ >>> Mailing list: https://launchpad.net/~dhis2-devs >>> Post to : dhis2-devs@lists.launchpad.net >>> Unsubscribe : https://launchpad.net/~dhis2-devs >>> More help : https://help.launchpad.net/ListHelp >>> >>> >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~dhis2-devs >> Post to : dhis2-devs@lists.launchpad.net >> Unsubscribe : https://launchpad.net/~dhis2-devs >> More help : https://help.launchpad.net/ListHelp >> >> >
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