User:Quartl/Assessments

Motivation

As more and more media are uploaded to Commons, categories are getting full and for users it becomes more and more difficult and time-consuming to find good quality and high value media on a certain subject. There are several existing approaches to battle this problem:

• Subcategories: Once categories become too full, subcategories are established which focus on a certain aspect. While this approach is of course useful from an organisational point of view, it may just shift the problem to forcing the user to browse several categories instead of one. Also, categories can still be quite full and already browsing 50 images to find the best one is time-consuming.
• Galleries: Gallery pages ideally summarize the available media a certain subject and users searching for content often start with them. However, galleries have to be maintained manually and new high quality or high value media are often not sorted into them. In addition, it is not clear what the requirements for inclusion into a gallery are.
• Quality images: QI seals indicate images of a certain quality level. They are awarded by community consensus. However, this approach is not systematic and many quality images have not yet been nominated. Also, QI seals only allow a two-way distinction: quality and non-quality image. Quality images are often not marked as such in galleries.
• Valued images: VI seals are awarded to those images which are most valuable in a certain scope. They are also awarded by community consensus and this approach is also not systematic. A VI seal only indicates the most valuable image, slightly less valuable images are not graded. Valued images are also often not marked as such in galleries.
• Featured pictures: FP awards are only given to outstanding pictures and thus refer to only a very small subset of available media.

One solution to this problem could be Quality and Value Assessments which are stored on the image description page or are somehow associated to the image (technical details have to be clarified later). These Assessments are done by experts or by community consensus. Galleries could then be constructed automatically from these ratings or users could give their preferences (show only images with Quality > 3, show only images with Value > 2, show all images) when browsing.

Quality Assessment

The Quality Assessment ranges between 0 and 6 points. Quality Images are characterized by at least 4 points without modifiers and could be automatically assessed according to the image size.

Base value

• 0: 0-0.25 mpx: 0 points
• 1: 0.25-0.5 mpx: 1 points
• 2: 0.5-1 mpx: 2 point
• 3: 1-2 mpx: 3 points
• 4: 2-4 mpx: 4 points
• 5: 4-8 mpx: 5 points
• 6: 8+ mpx: 6 points

Resolution modifiers

• T: subject covers less than 1/9 of the image: -1 points

Quality modifiers

• A: compression artefacts: -1 point
• N: visible noise: -1 point
• X: over- or underexposure or inappropriate lighting: -1 point
• S: oversaturated or unnatural colors: -1 point
• F: improper focus or insufficient depth of field: -1 point
• B: blur: -1 point
• C: bad composition: -1 point
• D: distortion: -1 point
• G: disturbing foreground or background: -1 point

In severe cases, 2 points are abducted by doubling the modifier.

Examples

• 
  5 - Quality 5
• 
  6TB - Quality 4
• 
  6NXC - Quality 3
• 
  4XF - Quality 2
• 
  2X - Quality 1
• 
  3TXB - Quality 0

Value Assessment

The Value Assessment ranges between 0 and 6 points. There is no correspondence to Valued Images which are based on relative value, so a Valued Image can have a Value Assessment of 0.

Value criteria for species:

Base value

• 0: least concern species: 0 points
• 1: near threatened species: 1 point
• 2: vulnerable species: 2 points
• 3: endangered or extinct species: 3 points

Size and difficulty modifier

• M: large mammals: +0 points
• O: molluscs: +0 points
• P: plants and fungi: +0 points
• N: small mammals (smaller than a cat): +1 point
• B: birds: +1 point
• R: reptiles: +1 point
• A: amphibians: +1 point
• F: fishes: +1 point
• I: large insects: +1 point
• J: small insects (smaller than a fly), bacteria, etc.: +2 points

Situation modifier

• -: resting: +0 points
• S: feeding, mating, moulting or other significant situation: +1 point

Setting modifiers

• D: dead or prepared specimen: +0 points
• U: unusual form or coloring: +1 point
• C: closeup on a specific detail: +1 point
• Z: zoo picture or other unnatural setting: -1 point

These modifiers are probably not yet complete. Value Assessments also have to be extended to media not dealing with species.

Examples

• 
  0IUS - Value 3
• 
  0IUC - Value 3
• 
  0IDU - Value 2
• 
  0IS - Value 2
• 
  0I - Value 1
• 
  0ISZ - Value 1