I only found out about this today, so I may have missed something. I have tried to use the demo, or at least I think I clicked through to it.
Anyway, I do have some questions and concerns. (These may be relevant to both the minimum viable product and future versions of the software.)
- When will the software overwrite existing values – always, sometimes or never? (The reason I ask, for those who are unaware, is that it's actually quite rare for it to be good practice to delete a previously valid value. Often either the new value should be marked as preferred (e.g. things that normally change over time) or the old value should be marked as deprecated (e.g. things that are newly discovered to be incorrect). In some cases none of the values should be preferred or deprecated (e.g. child (P40)), and in some cases multiple values may be preferred (e.g. occupation (P106)).)
- Will there be per-property or per-template options on Wikidata to specify what should happen when a value is modified, or will this be left to template creators? Allowing this to be set for each property would presumably save time and prevent stuff from breaking. (I think this might actually be possible with a Wikidata property to be used on other Wikidata properties, but that route wouldn't work for infoboxes that use the plain parser functions, as you would need a helper Lua module to bring the values to the templates.)
- Will the software surface the options to change preferred and deprecated ranks?
- If there are things that won't be editable through this interface, will the software assist the user in finding help or in modifying the item through the actual Wikidata interface?
- How will the software handle properties for which multiple values are used (e.g. occupation) and for which all (or some) of the values should be shown in an infobox?
- How will the software handle statements with qualifiers and references? If a value is overwritten, will the qualifiers and references stay? (Obligatory note that qualifiers can significantly change the meaning of a statement, especially for properties for which qualifiers are mandatory.)
- How will the software handle properties for which multiple statements with the same value but different qualifiers may be used (e.g. political offices held more than once, both non-consecutively and consecutively)? (I ask mainly because QuickStatements cannot add or modify such statements correctly.)
- On Wikidata, statements with an obvious sorting order are usually left out of order because it doesn't matter. If these are presented as sorted by the template (e.g. if Lua is used to sort the values), will the software be able to handle this properly or tell users not to break the existing values?
- Some Wikidata templates/modules can take the first value for a property (regardless of whether any values are preferred or deprecated) and discard the others. (I have recently used this configuration in several external link templates.) Will Wikidata Bridge be able to handle this? Will it be able to tell the user about the other values, if there are any?
- Will the software tell users how to add local parameters (e.g. fair use images) or allow users to do it through the interface?
- How will the software handle wikilinks? Assuming that the user is supposed to enter a page name and not a QID, if a user enters the title of a redirect that is linked to a Wikidata item, how will the software react? Will it ask the user to differentiate between the redirect's item and the target's item?
- How will the software handle units? As an example, on the English Wikipedia, both kilometres and miles may be acceptable for the same field, so it could be necessary to allow this to be modifiable (I would note that the demo/prototype actually omits the unit, which could be detrimental).
- Which datatypes will the software be able to support upon initial wide release? Is the goal to support every datatype, or just a subset of them?
As an editor of both Wikipedia and Wikidata, I'm cautiously supportive of this, but there are a lot of edge cases that would have to be handled before allowing random users to set this up everywhere, since you could break a lot of items by making it easy to enter bad data that looks correct into an infobox. It would be a shame if this just ends up making it more difficult for Wikidata editors to keep items in order.