View source for SE450:G4

==Next Meeting = 3/27 Tuesday 10:30am @ lab==
[[https://www.se.auckland.ac.nz/research/projects/softeng401.2007/056/Vivid%20Spatial%20Constellations%20v3.ppt Presentation Slides v3 FINAL]]

== Additional info for slides ==
Andrea> Hi guys! Yes, I agree, a short explanation of how VSICO works is good.

Here's some more info:

Domain VISCO has been developed for: The analysis of visual data in Geographical Information Systems. 


What is a GIS?

GIS allows people to study geographic information. There are 2 types of features in geographic information- Physical and Human. Physical features are things like rivers, lakes, mountains, buildings etc... Human features include population, migration,territories etc... So Visco has been designed for physical geographic information.[1]


Target users:

A range of industries use GIS. Eg. Forestry (to manage resources), agriculture (analysing crop yields), military (troop movement)[1]. The people using GIS would probably have come from a geography background, so understanding the concept of querying visual data would be easy for them. The physical metaphor of using real world, common household objects, is easily understood by most people, including users of VISCO.


References: http://www.gis.rgs.org/10.html

Other points about VISCO-

Progressive evaluation - Query is parsed as it is constructed, which allows 1)relationships to other objects to be calculated and 2) creates an animation of the effects of the query. This reduces error proneness.

Hidden dependancies - occur when layers are on top of each other (because within a layer there are no hidden dependancies).

Diffusiveness - using predefined operators = terse
	      - sketching from scratch = build complex queries with many layers
	     
Abstraction gradient - Building query from scratch lowers abstraction gradient, whereas having to use and interpret system icons raises abstraction gradient 

Typos on slide:

Last slide - "Diffusiveness through"???
Last slide - diagram: shouldn't an increase in abstraction gradient  decrease diffusiveness??

How about we remove "Target audience" from the first slide and be more specific? :-)

==Meeting on Tuesday 20th at 10:30am, the labs<br>==
[[https://www.se.auckland.ac.nz/research/projects/softeng401.2007/133/Vivid%20Spatial%20Constellations.ppt Presentation Slides]]
Vinty> Hi guys, I think for the presentation, we should say something, at least one or two sentences, about how VISCO works. (eg. what is constructing queries step by step?) Otherwise, I don't think they will understand the trade-off we are talking about. What do you think?  

Mary> I just realised after looking at the slides that we really have glossed over how VISCO works, we didn't really talk about what happens when you use it. For normal people who have never touched GIS systems, I can imagine that it'd be quite hard to grasp at first (I know I didn't really understand the paper until the examples!) So I'm thinking we should probably simply describe how to construct a very easy query (like the example we have on the slides with the 3 rectangles representing the layout of the building?) And so I added "Example Query: " on the intro page to remind Peter of it :)
I uploaded this as Presentation Slide v2 <br>
[[https://www.se.auckland.ac.nz/research/projects/softeng401.2007/102/Vivid%20Spatial%20Constellations%20v2.ppt Presentation Slides v2]] <br>
Changes I made in v2 were:<br>
- changed the trade-off diagram~ (please tell me if you like the new one better!) <br>
- added SOFTENG450 and Group 4 on the first slide <br>
- also, a very small issue, but I just thought it'd improve the readability of the ppt... replaced the ++ and -- on the last slide with ↑ and ↓

Vinty> I changed a little bit more on the slides, just make the sentences on the last slide more consistent, for exampel: Use of metaphor: +... -... I feel like this way is easier for people to understand.
The slide is uploaded onto the previous link

==New Updated Information on VISCO==
[[Image:Sampleviscoquery.JPG]]
[[Image:Viscoquerystructure.JPG]]<br>
A new paper (1 year later, 1998) on VISCO and updates of VISCO: https://www.se.auckland.ac.nz/research/projects/softeng401.2007/133/visco%20evolution.pdf <br>
See http://www.sts.tu-harburg.de/~mi.wessel/visco/visco.html<br>
Contains some up to date information regarding VISCO usage... as well as interface designs, including an incredibly low resolution 50mb quicktime on the usage of VISCO with a practical query, including stepping examples and reconstruction of a query based on backwards steps. Also includes an example of a running query as well as the results of the query before and after a modification.<br>
Quicktime link here from university:

==Meeting 1 minutes: Discussion of DSVLs and Evaluation of them==
===Abstraction Gradient===
Fragmentation occurs only once within components, and this creates a medium level in terms of abstraction since the components themselves may be comprised of only objects, but the components cannot be comprised of component parts.
===Closeness of Mapping===
Metaphor strength is high and only constraining factors require addressing in terms of closeness of mapping.
===Consistency===
Inferential programming is a key point in most languages, but this is a baseline comparison with other languages in this field, which we have no knowledge of. 
===Diffuseness===
Individual items are used in order to express components, and in the case of components, several objects, But never several components. Addresses flexibility within the language.
===Error-Proneness===
Metainformation is a lot of guessing at constraints, and CAN lead to errors. Incremental query building reduces errors.
===Hard Mental Operations===
None
===Hidden Dependencies===
With intersection/disjunction in addition to transparent layers there is a certain level of unresolved ambiguity. Invisible code also contributes to this problem.
===Premature Commitment===
All layers present are editable. No premature commitment required.
===Progressive Evaluation===
All queries can be analyzed stepwise and the construction of queries can also be done stepwise.
===Role-Expressiveness===
Animations show possibilities for objects and create possible component structures out of these animations.
===Secondary Notation===
System uses coloring automatically to address this, however this alters the parameters of 'secondary notation' and transforms it to a 'primary notation'
===Viscosity===
A component may need many steps in altering it, while an object may only need one step. Difficult to confirm without using the language. Relatively difficult to compare to other GIS systems.
===Visibility===
Layering attempts to address this, but there are still problems with intersection/disjunction and code visibility.
==Contact Details==



{|
|  <b>Name</b>    ||   <b>email</b>   ||   <b>cellphone</b>
|-
|   Charles    || clee204 ||   021 155 0257
|-
|   Bart   || bmsi001 ||  021 032 0261
|-
|   Mary   || kwei009 ||  021 207 5474
|-
|   Vinty   || qhua014 ||  021 181 6827
|-
|   Joe   || jlee265 ||  021 393 060
|-
|   Andrea   || ato003 ||  021 166 0540
|-
|   Peter   || prei033 ||  027 391 6834
|-
|}