Definitions and examples Flashcards
What is a conceptual data model?
Establish entities, attributes and relationships? An entity is an item or object, for example I could be an entity, my attributes might then be name, date of birth, etc.
What is an ERD (Entity relationship diagram)
Structural diagram for database design to visualise connections between entities. For example, again if I was an entity, and we had another entity of work place and another entity of home location, I the relationship would be [Home]<—-Lives at—[Louise]—-Works at—>[Work]
what is a logical data model?
This establishes the structure of data elements and the relationships among them. Similar to ERD but each entity will have its own listed attributes.
What is a physical data model?
Physical data model elaborates on the logical model by assigning limitations on columns such as type, length etc. It includes keys and types.
What is data cleaning and standardisation?
Removing unwanted values, outliers, and dealing with missing information.
What is the mean?
Average of the data
What is the median?
Middle number of a data set - more robust to outliers.
Mode?
Most frequent value that occurs in a dataset
Standard deviation?
Measure of the amount of variation of a set of values. How far each value lies from the mean. High = far from mean, low = clustered to mean
Variance
Measures how dispersed a dataset is.
Data Ethics five universal principles
Transparency, Accountability, Privacy, Fairness and Safety
Camden Data Charter - who was involved
Involve - public participation charity
Alan Turing Institute - National institute for data science
Wellcome Trust - research charity to improve health
Camden Data Charter - how did they do it
Chatted to residents, created a residents panel, representative speakers, show how data is currently used. Panelists agreed on changes to the Charter Principles
