Re: Schema.org extensions versus core

So, for example, schema:Course:

How would one quantitatively justify schema:Course in terms of impressions?
On May 6, 2015 4:44 PM, "Guha" <guha@google.com> wrote:

> I am referring to users of applications that consume the data (like search
> engines).
>
> guha
>
> On Wed, May 6, 2015 at 1:50 AM, Martin Hepp <martin.hepp@unibw.de> wrote:
>
>> Dear Guha:
>> Thanks for this important guideline! One question - could you please
>> clarify what you mean with:
>>
>> > 2. It must have at least 10m weekly users. Preferably 100m
>>
>> Does this refer to the number of times a type or facet is relevant for a
>> search engine query? Or the total number of human visitors to the Web sites
>> that implement the conceptual elements?
>>
>> Martin
>>
>>
>>
>> > On 06 May 2015, at 03:59, Guha <guha@google.com> wrote:
>> >
>> > There has been a request to clarify when something should go into an
>> extension versus when something should go into the core. Here is a first
>> stab at clarifying that.
>> >
>> > For something to be in the core, the following conditions must be
>> satisfied:
>> >
>> > 1. There must be at least a 1000 sites that will use it. Preferably
>> 10,000+
>> > 2. It must have at least 10m weekly users. Preferably 100m
>> > 3. The vocabulary must be relatively compact. Less than 20 terms.
>> >
>> > Of course, these are not hard constraints. We also recognize that
>> vocabularies evolve and more usage than planned might happen. We expect
>> terms or entire vocabularies to move from the extensions to core and vice
>> versa.
>> >
>> > This is a start of the discussion.
>> >
>> > guha
>> >
>>
>>
>> -----------------------------------
>> martin hepp  http://www.heppnetz.de
>> mhepp@computer.org          @mfhepp
>>
>>
>>
>>
>>
>