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Re: Use Cases vs. User Stories

From: Irene Polikoff <irene@topquadrant.com>
Date: Sun, 11 Jan 2015 11:42:08 -0500
Message-Id: <F52D2F75-FA10-4EFE-8EA4-BAA6DA16ECB8@topquadrant.com>
Cc: Public-data-shapes Wg <public-data-shapes-wg@w3.org>
To: Simon Steyskal <ssteyska@wu.ac.at>
Yes, LDP user stories are high grained. They are not the same as quickly implementable XP user stories, more like motivating scenarios of standard's application. I believe it is the same for our user stories.

LDP use cases, on the other hand, describe various actions (almost like methods) LDP API must support such as create container or retrieve description. They are not particularly formal at that, but they include snippets of RDF. If this is what we plan to do, then the use cases can only be done after the solution for representing RDF shapes is defined.

Irene

Sent from my iPhone

On Jan 11, 2015, at 4:33 AM, Simon Steyskal <ssteyska@wu.ac.at> wrote:

>> I think there has been no consideration given to being buildable in
>> short iterations, etc. Instead, it has been about informal stories as
>> a way to explain and ground the requirements. Similarly, in my
>> experience, people commonly use the term "use case" quite informally.
>> In the informal sense, there is very little difference between a use
>> case and a story.
> 
> +1
> 
> Nevertheless we might should stick to a similar approach as in the LDP use case & req. document described in [1]. Their user stories are rather informal stories of the form "XYZ wants to do ABC with JKL" and the respective use cases try to "formalize" those stories as you already pointed out.
> 
> Maybe we should start with the stories & requirements and leave the use cases aside for now?
> 
> simon
> 
> [1] http://www.w3.org/TR/ldp-ucr/
> 
> ---
> Dipl.-Ing. Simon Steyskal
> Institute for Information Business, WU Vienna
> 
> www: http://www.steyskal.info/  twitter: @simonsteys
> 
> 
> 
> Am 2015-01-09 21:01, schrieb Irene Polikoff:
>> Hmm… I don't believe the group is fully conforming to the XP
>> definition of the "user story". For example, referenced Wikepedia page
>> says:
>> · Stories are usually more fine-grained <than use cases> because they
>> have to be entirely buildable within an iteration (one or two weeks
>> for XP).
>> I think there has been no consideration given to being buildable in
>> short iterations, etc. Instead, it has been about informal stories as
>> a way to explain and ground the requirements. Similarly, in my
>> experience, people commonly use the term "use case" quite informally.
>> In the informal sense, there is very little difference between a use
>> case and a story.
>> With this I wonder if there was indeed a goal to produce formal use
>> cases expressed using some standard use case definition template (such
>> as post conditions, pre conditions, etc.) and possibly including UML
>> interaction diagrams?
>> Key differences noted between user stories and use cases are:
>> · Use cases organize requirements to form a narrative of how users
>> relate to and use a system. Hence they focus on user goals and how
>> interacting with a system satisfies the goals. Use case flows describe
>> sequences of interactions, and may be worded in terms of a formal
>> model.
>> Given this, what system would be described in such use cases? A
>> constraint validation engine? Something else?
>> · Must be accompanied and verifiable by test cases.
>> Will there be test cases for the system included with the use case
>> document?
>> Regards,
>> Irene
>> -----Original Message-----
>> From: Simon Steyskal [mailto:ssteyska@wu.ac.at]
>> Sent: Friday, January 09, 2015 4:33 AM
>> To: Public-data-shapes Wg
>> Subject: Use Cases vs. User Stories
>> Hi!
>> Since this WG should produce a "Use Case and Requirements" document
>> and we haven't defined any use cases so far, I was wondering whether
>> we should start a new wiki page for discussing/defining use cases, the
>> editors should come up with them, or we stick (at least for now) only
>> to our stories & requirements?
>> Unfortunately, UC and US are in general not interchangeable[2] (e.g.
>> in [1] both user stories and use cases are defined.)
>> cheers, simon
>> [1] http://www.w3.org/2012/ldp/hg/ldp-ucr.html [1]
>> [2] http://en.wikipedia.org/wiki/User_story#Comparing_with_use_cases
>> [2]
>> --
>> Dipl.-Ing. Simon Steyskal
>> Institute for Information Business, WU Vienna
>> www: http://www.steyskal.info/ [3] twitter: @simonsteys
>> Links:
>> ------
>> [1] http://www.w3.org/2012/ldp/hg/ldp-ucr.html
>> [2] http://en.wikipedia.org/wiki/User_story#Comparing_with_use_cases
>> [3] http://www.steyskal.info/
Received on Sunday, 11 January 2015 16:42:38 UTC

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