Hi all, over the past years a lot of people have rightfully complained about how we are handling rounding and uncertainty in quanity values. Until now when entering 124 m it will be parsed, stored and displaied as 124 +/-1 m. People then often tried to change this to 124 +/-0 m in order to prevent the uncertainty from being shown. This is often incorrect. People also disagreed with the default of +/-1 instead of +/-0.5. We have sat down and discussed at length how to improve this situation and have now prepared two changes: 1) If no uncertainty is explicitely entered, we do not try to guess it and no uncertainty will be displayed. But if an uncertatinty is given it will always be displayed even if it is +/-0. 2) In order to apply correct rounding (in particular for unit conversion) we still need to know the uncertatiny intervall. If no uncertainty was explicitely given we still will need to guess it. We have now halfed the default uncertainty intervall to be consistent with the rounding intervall. So for example 124 would be treated as 124 +/-0.5 when applying rounding.
We now have a lot of quantity values that are marked as exact (+/-0) while their uncertainty is not explicitely known. With the above changes all of these will be shown with +/-0. We also have a lot of values that have the old default precision (+/-1) which prevents the new default from being used. Therefor we suggest the following two bot runs: * Remove +/-0 from quantity values. * Remove the precision if it is equal to the old default precision. Both should be applied to properties that represent measured quantities. We should avoid applying them to properties that represent conversions or similar wexactly-defined values. We can prepare the bot for this. This requires a breaking change to the API and JSON binding. Daniel will send a separate email about that in a minute. We plan to make this change on the live system on November 15th. It can be tested on the beta before that. I will let you know when. Cheers Lydia -- Lydia Pintscher - http://about.me/lydia.pintscher Product Manager for Wikidata Wikimedia Deutschland e.V. Tempelhofer Ufer 23-24 10963 Berlin www.wikimedia.de Wikimedia Deutschland - Gesellschaft zur Förderung Freien Wissens e. V. Eingetragen im Vereinsregister des Amtsgerichts Berlin-Charlottenburg unter der Nummer 23855 Nz. Als gemeinnützig anerkannt durch das Finanzamt für Körperschaften I Berlin, Steuernummer 27/029/42207. _______________________________________________ Wikidata mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikidata
