The Ratings

I break my critiques up into categories because one big fat number on the end without justification serves little purpose. This helps extrapolate my feelings on a work to your inherently different weights.

Metrics by category:
Films (imdb)
Characters: How captivating the characters and their development throughout the movie is, along with how the actors portray the characters.
Screenplay: How the film unfolds and reveals itself. How engaging the plot is, the pacing, and the dialog. Directing. Just sit back, enjoy the ride and analyze later. You can rob yourself of a lot of surprise endings and twists by analyzing as you go along.
Cinematography: How the film does in immersion. The scene recording choices: the angle, lens, the lighting, grading, sound, score, etc.
Emotional: How well the film arouses an emotional investment. After watching the film, how much does it linger in my mind: do I want to watch it again? Do I want to discuss it?


Music (rym, last.fm, About the music setup)
Melody: How catchy, beautiful, fitting, etc. the main melody is.  This can be vocals, guitar, bass, a combination, etc.
Arrangement: How the other the instruments/vocals fit in and appeal to me.
Structure: How I liken the structure of the song.  This can include changes of style, mood, melody, length of sections.
Emotional: How the song impacts me.  This can include lyrics, ability to induce toe-tapping, etc.


Photos
Subject: Does the photo convey the subject without explanation? How aesthetic is the subject and the way it is revealed through light?
Composition: How do the eyes navigate the photograph? How is the relationship of the elements?
Technical: Lighting control (if applicable), focus, depth of field, camera settings, distractions, etc.

Emotional: How deeply does the concept and photo strike you?


A great resource for doing photo critiques can be found here. What I try to do is always keep a part of me a step back, to observe how I react. I try to look for an emotional response, as well as letting my eyes wonder and recall how they navigate through the photograph.

Performances
Aesthetic: How it appealed to the senses.
Structure: How the performance played out and flowed.
Technical: How technically impressive the performance was.
Emotional: Emotional Impact.


Books
Characters: How compelling and believable the characters are.
Plot: Flow of the story and ability to arouse interest.
Style: Ability of the author to captivate with words, scenes, imagery, and transcribe characters thoughts and actions.
Emotional: Measurement of eyelid-weight when closing the book for the night.

Food: yelp
Dish Ratings.
Service
Value
Local: Comparison to food in the area
Ambiance

Apps:
Aesthetic
Usability
Technical: Performance, bugs
Developer: Support, updates, etc.
Usefulness:



How Overall Ratings are Calculated: First, the subsections (be it subcategories or songs in an album) are added up. Then a log (base total number of subsections) is taken of that number and a regular grading scale is used:
0     0.00 - 0.50
1     0.51 - 0.60
2     0.61 - 0.70
3     0.71 - 0.80
4     0.81 - 0.90
5     0.91 - 1.00

or

0.0     0.00 - 0.25
0.5     0.26 - 0.55
1.0     0.56 - 0.60
1.5     0.61 - 0.65
2.0     0.66 - 0.70
2.5     0.71 - 0.75
3.0     0.76 - 0.80
3.5     0.81 - 0.85
4.0     0.86 - 0.90
4.5     0.91 - 0.95
5.0     0.96 - 1.00

I typically won't use these for smaller works that are not being reviewed as part of a larger work (e.g., not bundles).