08:17:42 RRSAgent has joined #poe 08:17:42 logging to http://www.w3.org/2017/05/18-poe-irc 08:17:44 RRSAgent, make logs public 08:17:44 Zakim has joined #poe 08:17:46 Zakim, this will be 08:17:46 I don't understand 'this will be', trackbot 08:17:47 Meeting: Permissions and Obligations Expression Working Group Teleconference 08:17:47 Date: 18 May 2017 08:17:59 RRSAgent, make logs public 08:18:09 present+ 08:18:17 Agenda: https://www.w3.org/2016/poe/wiki/Meetings:London2017 08:18:22 present+ 08:18:28 Chair: Renato/Ben 08:19:53 present+ 08:20:06 Hi guys - just trying to sort out wifi. Be with you soon. 08:22:02 Hope this helps: https://en.wikipedia.org/wiki/Wi-Fi 08:23:08 or this: http://www.dummies.com/computers/computer-networking/networking-components/configure-a-router/ 08:26:57 this will be a very peaceful f2f 08:27:32 Yes, technology ruins everything ;-) 08:29:04 phila has joined #poe 08:29:06 as long as they don't have to set up a beamer too.. :) 08:31:50 RRSAgent, make logs public 08:32:19 philA, who will dial-in ? 08:32:22 present+ Stuart, Victor, Michael, Dave, Ben, Phil, Linda_Burman 08:34:39 We should add "extraTable" to the ODRL vocabulary for future permissions ;-) 08:37:37 smyles has joined #poe 08:37:49 present+ 08:37:59 zakim, who is here 08:37:59 phila, you need to end that query with '?' 08:38:04 zakim, who is here? 08:38:04 Present: simonstey, renato, ivan, Stuart, Victor, Michael, Dave, Ben, Phil, Linda_Burman, extraChairs, smyles 08:38:06 On IRC I see smyles, phila, Zakim, RRSAgent, benws11111111112, renato, ivan, simonstey, trackbot 08:39:59 - extraChairs 08:40:12 zakim, who is here 08:40:12 renato, you need to end that query with '?' 08:40:28 zakim, who is here? 08:40:28 Present: simonstey, renato, ivan, Stuart, Victor, Michael, Dave, Ben, Phil, Linda_Burman, smyles 08:40:30 On IRC I see smyles, phila, Zakim, RRSAgent, benws11111111112, renato, ivan, simonstey, trackbot 08:40:33 davec has joined #poe 08:40:49 present+ 08:41:24 https://www.w3.org/2016/poe/wiki/Meetings:London2017 08:41:53 present+ 08:42:05 agenda: https://www.w3.org/2016/poe/wiki/Meetings:London2017 08:42:18 RRSAgent, draft minutes v2 08:42:18 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 08:43:11 michaelS has joined #poe 08:43:27 present+ 08:43:36 Linda has joined #POE 08:43:53 present+ 08:44:13 victor has joined #poe 08:44:15 present +victor 08:44:40 zakim, who is here? 08:44:40 Present: simonstey, renato, ivan, Stuart, Victor, Michael, Dave, Ben, Phil, Linda_Burman, smyles, davec, benws, michaelS, Linda 08:44:43 On IRC I see victor, Linda, michaelS, davec, smyles, phila, Zakim, RRSAgent, benws, renato, ivan, simonstey, trackbot 08:45:43 benws welcomes everyone to the london f2f + remote meeting and points to the agenda https://www.w3.org/2016/poe/wiki/Meetings:London2017 08:45:55 Topic: Requirements for an ODRL Processor 08:46:10 RRSAgent, draft minutes v2 08:46:10 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 08:46:31 q+ 08:46:32 renato what do we expect an odrl processor to do - expression, validation, enforcement? 08:46:57 renato this will determine what are the testing requirements 08:47:13 scribe: smyles 08:47:15 renato without specifying the nature of the odrl processor, we can't test it 08:47:18 scribeNick: smyles 08:47:28 +q 08:47:33 q- later 08:47:50 ack s 08:47:52 benws the authors of the formal semantics should be able to speak to the requirements 08:48:25 simon we need to clarify constraints in odrl - should an odrl processor do constraint checking? 08:48:52 simonstey we are in between - some constraints can be checked, others cannot be automatically evaluated 08:48:52 q+ 08:49:10 q+ to highlight https://w3c.github.io/poe/model/#dfn-odrl-processor 08:49:15 q+ 08:49:31 simonstey we should directly state - odrl processor must be able to check constraints (or decide not) 08:50:41 ok 08:50:54 s/ok// 08:50:57 simonstey constraints in odrl are currently a more concise version of the natural language expression. however, we have changed some constraints so that they could be automatically checked - e.g. current date or time 08:51:21 ack me 08:51:21 phila, you wanted to highlight https://w3c.github.io/poe/model/#dfn-odrl-processor 08:51:23 simonstey the question is should we fully follow that route - should odrl processor be able to evaluate constraints? 08:51:26 q+ 08:51:38 -> https://w3c.github.io/poe/model/#dfn-odrl-processor ODRL Processor 08:51:49 phila agress we should discuss what a processor should do. but we need to start with defining "what is an odrl processor?" 08:52:20 phila we have a definition "A system that provides services that creates, manipulates, and validates ODRL Policy expressions" 08:53:08 q- later 08:53:15 phila but we need to more fully specify the definition 08:53:36 michaelS exactly how should the processor be defined - is it a list of features? 08:53:54 phila yes, we should have a section in the document which lists all the things that a processor should do 08:53:56 q? 08:54:18 michaelS in the RightsML definition, yes we did believe that constraints should be evaluated 08:54:19 ack m 08:54:52 michaelS but the tricky thing in resolving constraints is interpreting the left operand. some are implicitly normative, others are explicitly non normative 08:55:32 michaelS we need to define the difference between normative and non normative more precisely 08:56:17 ack v 08:56:20 renato the normative and non-normative terms was based on the survey of current ODRL usage. if two or more uses were found a term was declared normative 08:56:24 http://delicias.dia.fi.upm.es/~vrodriguez/static/odrl/semantics1.pdf 08:56:37 q b 08:56:37 victor the editors of the formal semantics note met only once 08:56:40 q? 08:56:47 q+ 08:57:17 victor several possibilities were identified. SHACL was discussed, but maybe it doesn't cover everything? 08:57:35 victor should we require conversions between formats - XML, JSON, RDF? conclusion, no 08:57:53 victor should the processor validate profiles? also no 08:58:30 +q 08:58:42 victor other items were declared secondary. the main priority was to create a conformance validator 08:58:43 q+ 08:59:08 simonstey rules in the information model - you are able to check your policy conforms to the specification, e.g. via SHACL 08:59:31 simonstey odrl concepts all have shapes, which lets you confirm whether your policy conforms to the spec 08:59:59 q+ to distinguish between function and method 09:00:00 simonstey some constraints - e.g. absolute position - how can this be checked in a standardized way? 09:00:27 simonstey we as a working group must define how to automatically evaluate each constraint 09:00:48 simonstey some constraints are more straightforward, but many are too abstract to define in a standardized way 09:00:49 ack r 09:00:57 ack simonstey 09:01:17 renato it will be almost impossible to define constraint checking - too difficult to cover all cases 09:02:14 +q 09:02:18 renato we could validate that the expression is a valid ODRL policy, but it is out of scope to require that an ODRL processor can evaluate every constraint type 09:02:20 q? 09:02:27 ack benws 09:02:29 ack iv 09:02:46 q+ 09:02:52 ivan wondering whether it makes things too complicated to discuss "one" odrl processor 09:03:24 ivan there are several different type of task - saying they are all the same thing. perhaps it is better to discuss them using different names 09:03:55 ivan do we only have one odrl processor? no. we have a constraint processor (one kind) but several other kinds too 09:04:16 s/ivan /ivan: /g 09:04:21 ack me 09:04:21 phila, you wanted to distinguish between function and method 09:04:23 benws in the standard we should discuss a processor which validates that the processor is syntactically correct 09:04:44 phila agree that there should be a level beyond which we should not go 09:05:55 phila should an odrl processor as defined by the group check for conformance to the odrl standard? or do we say that an odrl processor requires valid odrl as an input 09:06:31 s/phila/phila:/g 09:07:21 q? 09:07:41 phila: an odrl processor does need to be able evaluate constraints - "is the sky blue?" "all of those things must be jpegs" - those are not things that can be specified within turtle or XML, therefore they must be evaluated via the processor 09:08:39 simonstey: constraint checking is integral - e.g. a duty is not fulfilled unless all of the constraints are satisfied 09:08:54 q+ 09:09:48 simonstey: for formal semantics - we could say "either a constraint evaluation result is either true or false". but i'm not sure if we need to help users more than that? 09:10:05 ack v 09:10:50 victor: we should have a numbered list of features that a processor must support. but are some features automatic and some are not? 09:11:23 ack s 09:11:31 q+ 09:11:37 ack r 09:11:42 phila: there are different types of constraints - some which can be evaluated automatically, but some not. and we need to prove that we have different machines that will provide the correct and consistent results 09:12:16 renato: we do talk about constraints in the spec. but currently not any further details on how to evaluate the constraints 09:12:30 CarolineB has joined #Poe 09:13:03 renato: should we have an odrl processor that validate syntax and something else (not called a "processor") which evaluates the constraints 09:13:06 Present+CarolineB 09:13:06 +1 to Renato 09:13:18 RRSAgent: 09:13:18 I'm logging. I don't understand '', phila. Try /msg RRSAgent help 09:13:29 RRSAgent, draft minutes v2 09:13:29 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 09:14:13 benws: is there room for a different part of the processor which says "given that the constraint is satisfied" (even if we don't say how) "then this permission is actionable" 09:14:34 s/^renato /renato: /g 09:14:41 RRSAgent, draft minutes v2 09:14:41 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 09:14:58 simonstey: we could say "if all of the constraints are satisfied then the action is actionable" 09:15:09 simonstey: we could say "if all of the constraints on a duty are satisfied then the action is actionable" 09:15:13 s/renato /renato: /g 09:15:21 RRSAgent, draft minutes v2 09:15:21 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 09:15:30 i can see an easy task to build an automated processor if "constraint validation" is a made as a "black box". 09:16:17 s/benws /benws: /g 09:16:34 benws: if a constraint (a left operand) was strongly defined in a profile to have a meaning within the context then we could evaluate the permission 09:16:40 s/simonstey /simonestey: /g 09:16:56 q+ 09:17:06 s/michaelS /michaelS: / 09:17:26 s/victor /victor: / 09:17:30 s/victor /victor: /g 09:17:33 benws: perhaps we should require that all profiles meet that definition standard - that they must be precisely defined within a context 09:17:33 s/michaelS /michaelS: /g 09:17:34 https://w3c.github.io/poe/vocab/#term-absoluteSpatialPosition 09:17:49 RRSAgent, draft minutes v2 09:17:49 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 09:17:56 q? 09:18:03 q+ 09:18:03 ack benws 09:18:05 q+ 09:18:11 simonstey: an example of a constraint which cannot be checked in a general way is absolute position 09:18:25 victor: points out that some constraints could be manually checked 09:19:02 http://w3c.github.io/poe/vocab/#term-absoluteTemporalPosition 09:19:10 michaelS: example - advertising clip has to be between 1 minute and 1.30 minute of a stream. how could this be checked by an ODRL processor? 09:19:12 ack m 09:19:43 michaelS: how well do some left operands work? such as count of usages? 09:19:51 q+ 09:20:24 benws: there is only so far we can go in machine readable representation 09:21:05 davec: many of these constraints are not edge cases 09:21:17 benws: agreed 09:21:33 ack r 09:21:43 davec: some constraints can't be done programmatically, but are core to odrl 09:22:12 renato: we should take the black box approach for constraints. how else can we cover all the cases? 09:22:24 Side note: I find the word "processor" too broad. For example, I can conceive a service that given a ODRL expression, an automatically generated English expression is given. This would be a "processor", wouldn't it? I believe that this software would abide to the constraints we are discussing now --although not called "processor", but "validator" 09:22:35 q? 09:22:42 renato: if we try to enforce constraints, then there is a risk that our group would be misunderstood in is intent 09:23:21 renato: we can have a processor which validates the odrl properties, but the actually checking of the constraints needs to be done by some external system 09:23:36 ack me 09:23:39 renato: POE has the word "expression" in the name, since that is the scope 09:23:54 q+ 09:24:00 phila: the notion of "actionable" is useful 09:24:17 smyles: I agree with where we seem to be getting 09:24:40 ... The thing I built that I call an ODRL processor, consults context 09:25:05 ... It asks "is this constraint satisfied" but doesn't ask how do you know 09:25:07 q 09:25:10 q? 09:25:16 ack s 09:25:32 smyles: The separation is useful as is the black box concept 09:25:33 ack i 09:25:45 ivan: i agree but ... 09:26:05 ivan: the processor must be more than what, say, SHACL can do 09:26:21 ivan: this would then be a testable thing for our CR criteria 09:26:54 LindA: will the ODRL engine check whether the constraint has been processed? 09:26:55 q+ 09:27:29 ack i 09:28:04 q+ 09:28:10 ivan: do we need an engine, which depends on the true or false of the constraint evaluation and then acts upon it 09:28:26 ivan: if so, then this evaluation must be defined and testable 09:29:16 phila: each constraint needs to be evaluated via a "black box" which returns "true or false" 09:29:28 q+ 09:29:35 ack p 09:29:53 benws: the processor then makes decisions based on the true / false status of the constraints 09:29:58 ack r 09:30:05 renato: can the black box be a human? 09:30:09 everyone: yes! 09:31:03 phila: it is literally true or false coming back from the API 09:31:22 lindA: introduces herself to the team 09:31:24 https://www.linkedin.com/in/lindaburman/ 09:31:41 davec: introduces himself to the team 09:31:56 https://www.linkedin.com/in/davecompton/ 09:32:09 q? 09:32:47 benws: asking whether formal semantics support the odrl processor we have just agreed? 09:32:54 victor: yes i think so 09:33:19 simonstey: yes, since something else will do the actual constraint evaluation 09:33:38 victor: if we do an implementation, will that count? 09:33:41 phila: yes 09:34:07 phila: stages. the concept of an odrl processor, then the 09:34:23 proposal: we define fully the concept of an odrl processor 09:34:39 ... 09:34:41 +1 09:34:57 phila: knowing that we therefore have to show independent implementations exist 09:35:23 phila: they don't have to be open source or commerical or public, but they must be shown to exist 09:35:28 +1 09:35:34 +1 09:35:35 +1 09:35:36 +1 09:35:38 +1 09:35:38 +1 09:35:42 +1 09:35:43 +1 09:35:47 +1 09:36:05 resolution: we define fully the concept of an odrl processor 09:36:32 phila: what does the odrl do (and not do)? 09:37:00 phila: do we want validation of the odrl policy a part of the processor? 09:37:17 benws: it is better to split validation from processor 09:38:07 victor: we should have a validator and something else 09:38:17 victor: what should we call the "something else" 09:39:14 policy 09:39:19 linda: evaluation is not sufficient to determine whether something is actionable 09:39:47 michaelS: we should not forget about restrictions 09:40:03 benws: suggest - a validator and an evaluator 09:40:05 q? 09:40:30 phila: the process of validation is seperate from evluation 09:40:44 s/evluation/evaluation/ 09:41:04 +q 09:41:39 michaelS: validation could include structural items, such as duties can only be there for permissions not restrictions 09:41:43 ack s 09:42:06 simonstey: on the one side is syntactic validation and on the other semantic validation 09:42:34 simonstey: semantic validation could detect contradictory statements, for example 09:43:01 benws: three elements? syntactic validation, semantic validation and then evaluation 09:43:12 simonstey: no, just syntactic and semantic validation 09:43:26 benws: you also need to know whether the policy is actionable or not 09:43:40 q+ to say you can't eliminate nonsense 09:44:09 simonstey: if you already know whether a policy is semantically correct then is there anything left for evaluation? 09:45:03 phila: syntactic validation tends to mean just whether a parser can read the file, so we are really talking about "semantic validation" 09:45:05 s/syntactic/structural ? 09:45:41 phila: can you write a syntactic and smenaticaly valid policy which is still nonsense? yes 09:45:49 q- 09:46:16 simonstey: if two rules are not actionable at the same time, you need to evaluate them - such as for conflict detection 09:46:34 simonstey: structural validation - is this valid odrl? 09:46:58 benws: aggregations of policies is an issue, for later debate 09:46:59 q+ 09:47:16 benws: we should only discuss the processor 09:47:30 benws: structural validation for correct odrl 09:48:07 benws: given values (e.g. via an API) for constraints being true or false, then there is an evaluation step to determine whether the policy is actionable 09:48:29 ack d 09:49:09 davec: how do we handle contradictory constraints? 09:49:22 benws: this is beyond the scope of what we're talking about 09:49:52 benws: odrl validator and an evaluator 09:50:12 ODRL Validator = odrl policy meets IM requirements 09:51:00 proposal: an odrl validator checks the correctness of the policy 09:51:37 [debate about what does "correctness" mean] 09:51:43 conformance? 09:52:04 ivan: could we define correctness by the set of tests we define 09:52:33 victor: correctness has a specific meaning, will this be confusing 09:52:43 :-) 09:53:06 proposal: an odrl validator checks the conformance of the policy to the ODRL standard 09:53:12 +1 09:53:18 +1 09:53:19 +1 09:53:20 +1 09:53:21 +1 09:53:21 +1 09:53:22 +1 09:53:26 +1 09:53:38 +1 09:54:18 proposal: an odrl evaluator determines whether the policy is actionable, including with reference to external boolean returning processes 09:54:27 +1 09:54:30 resolution: an odrl validator checks the conformance of the policy to the ODRL standard 09:54:41 RRSAgent, draft minutes v2 09:54:41 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 09:55:38 +q 09:55:55 proposal: an odrl evaluator determines whether the policy is actionable 09:56:08 ack s 09:56:21 simonstey: what does it mean for a policy to be actionable? 09:56:48 proposal: an odrl evaluator determines whether the permission is actionable 09:56:54 Rule? 09:57:46 proposal: an odrl evaluator determines whether the permissions and prohibitions of a policy are actionable 09:58:34 +1 09:58:36 +1 09:58:39 +1 09:58:39 +1 09:58:40 +1 09:58:44 0 09:58:44 +1 09:58:47 0 09:58:47 +0 09:58:50 +0.9 09:59:01 i dont think an external reader will understand the word actionable 09:59:28 simonstey: what does it mean to be "actionable" in this context 09:59:40 i woulud speak in terms of actions, not prohbitions and permissions 10:00:27 michaelS: we should be careful - actions are only parts of the permissions and prohibitions 10:01:05 benws: that is not the job of the evaluator 10:01:36 renato: the evaluator is really about evaluating constraints and duties 10:02:17 renato: the evaluator is mainly about checking whether the constraints are satisfied 10:03:02 phila: we are trying to determine what the evaluator does and what the black box does 10:04:06 michaelS: is the verb "applies" clearer? 10:04:27 benws: applies to ... what? 10:04:52 benws: "in effect" captures the concept more precisely 10:06:09 proposal: an odrl evaluator determines whether the permissions and prohibitions of a policy are in effect 10:06:12 +1 10:06:12 +1 10:06:13 +1 10:06:14 Linda has joined #POE 10:06:14 +1 10:06:16 +1 10:06:19 +0 10:06:20 +1 10:06:23 +0.99999999 10:06:23 +1 10:06:35 +1 10:08:11 +1 10:08:59 resolution: an odrl evaluator determines whether the permissions and prohibitions of a policy are in effect 10:10:10 RRSAgent: 10:10:10 I'm logging. I don't understand '', phila. Try /msg RRSAgent help 10:10:20 Back in 20 mins 10:11:05 phila: does an evaluator specify whether a set of permissions and restrictions are in effect for a specific use 10:11:13 RRSAgent, draft minutes v2 10:11:13 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 10:11:19 phila: does an evaluator specify whether a set of permissions and restrictions are in effect for a specific target 10:11:37 [coffee or tea break] 10:11:46 RRSAgent, draft minutes v2 10:11:46 I have made the request to generate http://www.w3.org/2017/05/18-poe-minutes.html phila 10:30:18 nandana has joined #poe 10:30:29 back 10:34:58 we too - slowly 10:34:58 We're back too 10:39:08 scribe: phila 10:39:11 CarolineB has joined #Poe 10:39:16 scribenick: phila 10:39:34 phila: in re-reading the spec, i was looking at the discussion of "scope" 10:39:45 https://w3c.github.io/poe/model/#asset-scope 10:39:53 phila: the target - where does the permission apply 10:40:04 https://w3c.github.io/poe/model/#party-scope 10:40:13 phila: within that, you can add a "scope" - the value given was a URI 10:40:20 http://w3c.github.io/poe/model/#asset-scope 10:40:46 phila: the URI given was meant - via some voodoo - "this is only applicable to e.g. JPEGs" 10:40:52 benws: connection with processing? 10:41:05 phila: there is a lot of processing going on there 10:41:09 q+ 10:41:15 benws: the target can be one or more URIs 10:41:32 benws: what those URIs mean is outside the scope of URI 10:42:09 renato: what exactly is the problem with scope? 10:42:37 renato: scope limits the application of that particular permission to URIs that match that additional scope URI 10:42:52 q? 10:43:09 renato: e.g. you refer to a catalogue, then you limit to to a subset of the catalogue that match the scope parameter 10:43:19 benws: how is this different than a constraint? 10:43:23 scribeNick: smyles 10:43:42 q+ 10:43:48 renato: it could be handled by constraint in that particular example, but there is also a scope process for parties and assets 10:43:52 victor has joined #poe 10:44:09 benws: is scope really just syntactic sugar? ans so could it be eliminated? 10:44:14 s/ans/and/ 10:44:28 benws: constraints could be applicable to the target 10:44:43 +q 10:44:46 +q 10:45:14 benws: is scope anything beyond what you can do with constraints? 10:45:55 renato: this was a requirement which was accepted by the working group, so we can eliminate it, but we did previously discuss and agree 10:46:17 phila: the processor needs to understand that.. 10:46:32 q? 10:46:36 benws: no, processors cannot understand constraints themselves 10:47:12 benws: processors use the results of constraint evaluation, the odrl engine does not in itself evaluation scope 10:47:36 phila: will be happy if the requirement can be satisfied via constraints and so eliminate scope as a different concept 10:47:46