Turn in lab 5 Put your name, per number and lab section on your answer sheet.

Lab 6: Symbology Yingjie Hu

Objective The cartographic strategies used to represent features on the map.

Generalization In order to clearly represent the features on the complex Earth surface, we need to generalize them before put them on the map. Generalization strategies: – Selection, simplification, combination, location shift and exaggeration.

Selection Select important features and omit the unimportant ones.

Simplification

Combination

Location shift

Exaggeration

Two data types on the map Qualitative – Different states in U.S. – Different species in an area Quantitative – Population in each state – Birth rate in different area

Levels of Measurements Nominal – Qualitative data, like state name or class name Ordinal – Quantitative data. Used to measure the ranks. Interval – Quantitative data. Used to measure the data which doesn’t have a true “zero” Ratio – Quantitative data. Used to measure the data which an absolute “zero”, like distance.

Nominal

Ordinal

Interval

Ratio

Visual variables Shape, hue, and texture – Qualitative data Size, Gray-tone value, orientation – Quantitative data

Visual variables — shape

Visual variables — hue

Visual variables — texture

Visual variables — size

Visual variables — gray tone

Visual variables — orientation

Visual variable combination Combine several visual variables together – hue and orientation

Visual variables Shape, hue, and texture are appropriate for representing qualitative data, while size, gray- tone value, and orientation are appropriate for representing quantitative data. Combining several visual variables together to better represent features on the map. – size and hue – Shape and gray-tone

Assignment Complete lab 6 symbology Due date: Next Thursday (Nov. 17th) Powerpoint online: