GoodRelations is a standardized vocabulary for product, price, and company data that can (1) be embedded into existing static and dynamic Web pages and that (2) can be processed by other computers. This increases the visibility of your products and services in the latest generation of search engines, recommender systems, and other novel applications.
Martin Hepp
martin.hepp at ebusiness-unibw.org
Fri Jul 20 07:21:19 CEST 2012
Dear all: In the context of the ongoing work of making GoodRelations directly available from the schema.org namespace, there was a discussion on the difference between the use of validFrom/validThrough attached to gr:Offering vs. gr:UnitPriceSpecification. I am relaying my reply below since I assume this topic is relevant for a broader audience. Best Martin Hepp Begin forwarded message: > >> in the GR integration proposal, is the field validThrough on Offer really needed? There is already priceValidUntil in http://schema.org/Offer. If it's needed, could you please disambiguate the two? > > Let me first provide a little bit of background: > > The two properties validFrom/validThrough can be applied to several GoodRelations types: > > 1. gr:Offering > 2. gr:PriceSpecification, including specializations like gr:DeliveryChargeSpecification, gr:PaymentChargeSpecification, and > gr:UnitPriceSpecification > 3. gr:License > 4. gr:OpeningHoursSpecification > > The semantics is always the same: It limits the temporal validity of the respective statement. > > The difference between attaching it to an offer vs. attaching it to a UnitPriceSpecification is that the former defines the validity of the offer and the latter the validity of the price. Both is pretty important: > > You may want to say that you offer rooms for rent from June 1 - September 30, which is then a property of the offer, i.e. the promise to grant someone some rights on something. > > You may also want to have two different prices for non-overlapping periods of time, e.g. an apple costs 2 USD regularly, but only 1 USD on July 4, 2012. Then, validFrom/validThrough is a property of the two price specifications. > > http://wiki.goodrelations-vocabulary.org/Cookbook/Pricing#Seasonal_Discounts_and_Special_Offers. > > Now, in the case of the schema.org integration, we have two ways of modeling prices: > > a) The simple, original schema.org pattern with the three properties > > price Number or Text The offer price of the product. > priceCurrency Text The currency (in 3-letter ISO 4217 format) of the offer price. > priceValidUntil Date The date after which the price is no longer available. > > **directly applied to the http://schema.org/Offer entity***, and > > b) the advanced GoodRelations pattern with a dedicated price entity, which allows quantity discounts, billing increments, etc. - lots of things that we need for more advanced pricing, in particular the video examples from > > http://wiki.goodrelations-vocabulary.org/Cookbook/Video_content > > So we will have the following choices with the enhanced http://schema.org/Offer itemtype: > > a) Offer with a simple price pattern > validFrom datetime - the start of the validity of the offer > validThrough datetime - the end of the validity of the offer > priceValidUntil date - the end of the validity of the price > > Note that certain legislations (e.g. in Germany) lean towards requiring price comparison sites to suppress expired prices. In that case, you may want to know that the offer is still valid, even if the price expired. > > b) Offer with an advanced price pattern > http://schema.org/Offer > validFrom datetime - the start of the validity of the offer > validThrough datetime - the end of the validity of the offer > > http://schema.org/UnitPriceSpecification > validFrom datetime - the start of the validity of the price > validThrough datetime - the end of the validity of the price > -------------------------------------------------------- martin hepp e-business & web science research group universitaet der bundeswehr muenchen e-mail: hepp at ebusiness-unibw.org phone: +49-(0)89-6004-4217 fax: +49-(0)89-6004-4620 www: http://www.unibw.de/ebusiness/ (group) http://www.heppnetz.de/ (personal) skype: mfhepp twitter: mfhepp Check out GoodRelations for E-Commerce on the Web of Linked Data! ================================================================= * Project Main Page: http://purl.org/goodrelations/