The Data Model
2 likes840 views
The document by Tim Sheiner discusses data models, focusing on the organization and storage of data within digital machines, particularly through examples like backpacking stoves. It emphasizes the significance of name:value pairs, vectors, and matrices in structuring data, alongside crucial concepts such as inheritance, taxonomy, and controlled vocabulary in data modeling. Various challenges in designing an effective data model and communicating it through hierarchies and sets are also explored.
The Data Model
- 1. Data Model Who lives here? № 6, Design of Digital Machines Tim Sheiner 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States.
- 2. The four sub models of the machine object model Input Controller Output View Model Digital Machine interaction model data model conceptual model The data model corresponds most closely to the model. 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 2
- 3. What is stored where? The data model defines storage. ๏ what information is stored? ๏ how is the store organized? Storage, in turn, defines inheritance ๏ how do I get from here to there? ๏ what attributes will I find when I get there? 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 3
- 4. Let’s begin to understand the data model by starting with the data 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 4
- 5. An example: backpacking stoves 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 5
- 6. Specifically, the old skool fav: 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 6
- 7. Data is details 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 7
- 8. Name:value pairs are a simple structure item # 708999 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 8
- 9. Name:value pairs are a simple structure name value item # 708999 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 8
- 10. Name:value pairs are a simple structure name value item # 708999 brand MSR model WhisperLite Shaker Jet price $79.95 auto ignition no weight 11 oz average boil time 238 sec 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 8
- 11. Name:value pairs are a simple structure name value item # 708999 brand MSR model WhisperLite Shaker Jet price $79.95 object properties or attributes auto ignition no weight 11 oz average boil time 238 sec object 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 8
- 12. A group of name:value pairs is a vector item # 708999 brand MSR model WhisperLite Shaker Jet price $79.95 auto ignition no weight 11 oz average boil time 238 sec variables values vector 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 9
- 13. Vectors can be written as an array (item #, brand, model, price, auto ignition, weight, average boil time) (708999, MSR, WhisperLite Shaker Jet, 79.95, no, 11, 238) 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 10
- 14. Vectors can be written as an array (item #, brand, model, price, auto ignition, weight, average boil time) variables (708999, MSR, WhisperLite Shaker Jet, 79.95, no, 11, 238) values 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 10
- 15. Vectors can be written in matrix form average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 79.95 no 11 238 Shaker Jet 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 11
- 16. A collection of vectors is matrix or a table average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 80 no 11 238 Shaker Jet 722001 MSR XGK EX 150 no 13 296 813622 Jetboil Sol 120 yes 11 300 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 12
- 17. More terminology average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 80 no 11 238 Shaker Jet 722001 MSR XGK EX 150 no 13 296 813622 Jetboil Sol 120 yes 11 300 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 18. More terminology columns (variables) average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 80 no 11 238 Shaker Jet rows 722001 MSR XGK EX 150 no 13 296 (values) 813622 Jetboil Sol 120 yes 11 300 a record (a vector) record ID (must be unique) 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 19. More terminology columns (variables) average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 80 no 11 238 Shaker Jet rows 722001 MSR XGK EX 150 no 13 296 (values) 813622 Jetboil Sol 120 yes 11 300 a record (a vector) record ID categorical (must be unique) 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 20. More terminology columns (variables) average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 80 no 11 238 Shaker Jet rows 722001 MSR XGK EX 150 no 13 296 (values) 813622 Jetboil Sol 120 yes 11 300 a record (a vector) record ID categorical continuous (must be unique) 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 21. More terminology columns (variables) average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 80 no 11 238 Shaker Jet rows 722001 MSR XGK EX 150 no 13 296 (values) 813622 Jetboil Sol 120 yes 11 300 a record (a vector) record ID categorical continuous (must be unique) boolean (special kind of category) 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 22. More terminology columns (variables) average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 80 no 11 238 Shaker Jet rows 722001 MSR XGK EX 150 no 13 296 (values) 813622 Jetboil Sol 120 yes 11 300 a record (a vector) record ID categorical continuous (must be unique) boolean (special kind of category) time (special kind of continuous) 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 23. Statistics are not data average boil item # image brand model price ($) auto ignition weight (oz) time (sec) WhisperLite 708999 MSR 79.95 no 11 238 Shaker Jet 722001 MSR XGK EX 149.95 no 13.2 296 813622 Jetboil Sol 119.95 yes 10.5 300 Averages 116.62 11.6 278 data statistic When used as a presentation tool, tables often mix data and statistics. Data are observations. Statistics are methods of aggregating, compressing and transforming data. 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 14
- 24. Now we understand data. What about the data model? 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 15
- 25. Data are the observations weight EGK EX Pocket Rocket image brand price ($) (oz) MSR 80 11 MSR 150 13 $149.95 $39.95 13.2 oz 3 oz Jetboil 120 11 WhisperLite Shaker Jet MSR 40 3 Sol $79.95 11 oz $119.95 10.5 oz 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 16
- 26. The data model is the organization Camping & Hiking data model Backpacking Stoves Liquid Fuel Canister Activity MSR MSR EGK EX Pocket Rocket Equipment Type Equipment Subtype Brand $149.95 $39.95 Model 13.2 oz 3 oz metadata Jetboil WhisperLite Shaker Jet Sol $79.95 11 oz $119.95 10.5 oz 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 17
- 27. The data model is a point of view about inheritance descendent - Camping & Hiking parent-child relationship Activity - Backpacking Stoves Equipment Type - Liquid Fuel Stoves Equipment Subtype - MSR Brand - WhisperLite Shaker Jet siblings Model - EGK EX metadata - Canister ancestor - MSR siblings - Pocket Rocket - Jetboil - Sol 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 18
- 28. The data model is a point of view about inheritance descendent - Camping & Hiking parent-child relationship Activity - Backpacking Stoves Equipment Type - Liquid Fuel Stoves Equipment Subtype - MSR Brand - WhisperLite Shaker Jet siblings Model - EGK EX metadata - Canister ancestor - MSR siblings - Pocket Rocket - Jetboil - Sol a point of view, not the point of view 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 18
- 29. The data model is an general inheritance solution for all system objects instance model Camping & Hiking>Backpacking Stoves>Liquid Fuel Stoves>MSR>WhisperLite Shaker Jet Activity Equipment Type Equipment Subtype instance Kayaking & Canoeing>Canoes>Recreational Canoes>Mad River>Adventure 16 Brand Model instance Climbing>Chalk>Chalk Bags>Prana>Eagle Eye 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 19
- 30. The data model is an general inheritance solution for all system objects instance model Camping & Hiking>Backpacking Stoves>Liquid Fuel Stoves>MSR>WhisperLite Shaker Jet Activity Equipment Type Equipment Subtype instance Kayaking & Canoeing>Canoes>Recreational Canoes>Mad River>Adventure 16 Brand Model instance Climbing>Chalk>Chalk Bags>Prana>Eagle Eye a solution, not the solution 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 19
- 31. Communicating the Data Model Several standard forms ๏ hierarchy ๏ set diagram ๏ illustration 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 20
- 32. Data Model Example Hierarchy & Sets This baroque example includes a simple hierarchy illustrating the general case, and then a modified set display to demonstrate a specific case. 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States.
- 33. Data Model Example Illustration An illustration can be helpful to show relationships between sibling nodes in the structure. 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States.
- 34. How do you design a data model? 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 23
- 35. Data modeling challenges ๏ Controlled Vocabulary a restricted list of names for the objects in the system ๏ Taxonomy a hierarchical structure that defines the inheritance relationships in the system ๏ Metadata the object attributes used to distinguish taxonomic siblings ๏ Information Architecture the design of the vocabulary, taxonomy and metadata 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 24
- 36. Controlled vocabulary captures meaning The Whorfian hypothesis is about the question of whether words influence thought. Data modeling is agnostic with respect to this question, but deterministic on the point that words influence communication. The controlled vocabulary should capture the terms used by system experts to communicate precisely. Edward Sapir/Benjamin Whorf Different words for different states of rice 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 25
- 37. Taxonomy is arbitrary Originally, taxonomy described a method for classifying the natural world. In the context of a data model, it is the rule set by which objects are placed into a hierarchical structure based upon a controlled vocabulary. Regardless of how carefully and objectively these rules are constructed, never doubt that they are by definition arbitrary. Carl Linnaeus 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 26
- 38. Metadata separates siblings data model instance Activity - Camping & Hiking Equipment Type - Backpacking Stoves Equipment Subtype - Liquid Fuel Stoves Brand - MSR Model - WhisperLite Shaker Jet metadata - item #: 708999 - price: $79.95 - weight: 11oz - EGK EX - item #: 702201 - price: $149.95 - weight: 13oz 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 27
- 39. Information architecture is the art Information architecture is the design of the data model Data Storage System Navigation Information Display Activity - Camping & Hiking Equipment Type - Backpacking Stoves Equipment Subtype - Liquid Fuel Stoves Brand - MSR Model - WhisperLite Shaker Jet Information architecture’s concern is a data model that is functional across cases 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 28
- 40. fin 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 29