Presenting GIS Data

Map design is an interative multi-step process:

1. Select

2. Arrange

3. Symbolize

4. Review

5. Edit

Objective

Each step of map design refers back to the _________ for the map.

Determining the objective.

The most important design step is…

1. What is the purpose?

2. Who is the audience?

3. What is the medium?

4. Under what conditions will it be viewed?

Key questions for designing an objective:

Locating points of interest (google maps)

Navigating from one place to another (road atlas)

Compiling complex collected data (geologic map)

Convincing the reader of a fact or hypothesis

Comparing data from different times or locations

Analyzing data to learn new information

Etc.

Purposes of maps:

Who will be viewing the map?

What is their expected level of knowledge?

• About subject matter

• About maps in general

Do they have special requirements?

Color blindness, large print?

Important audience considerations:

Paper map

• Report, wall map, poster, etc. 

Electronic files

• PDF, GIF, etc. 

• What format(s)? File sizes? Delivery method?

Computer screens

• What size? which types of computers?

Projection screen

Mobile devices

• Tablets? Smartphones?

Possible map mediums:

Static and unchanging

Fixed paper size and scale

High resolution

May be complex with many levels of information

View is committed

May serve multiple purposes

Paper maps are characterized by being:

Interactive

Viewing size may vary by device

Poor light/sunlight on mobile divices

Short viewer attention span

Competes for attention

Should do one thing really well

Web maps are characterized by being:

Good maps tell a story

• Who are the lead players?

• Which layers play a supporting role?

• Do some layers distract from the story?

Selecting data layers:

Privacy issues

Sensitive information that requires approval

Unintended consequences

Data omission:

Cartographic generalization

Simplification of a data set for better performance on a map.

Exaggerate, displace, typify, reclassify, collapse, aggregate, simpligy, or refine data. 

A cartographer might:

Graticule, measurement, index

Map grids:

Graticule grids

Put longitude-latitude marks around the map frame.

Measurement grids

Show x,y coordinates. 

Index grids

Show lettered and numbered squares.

Map elements

Placed on a layout to support the map.

Location map

Title

Scale bar

Legend

North arrow

Neatlines

Citations

Graphics or photos

Examples of map elements:

Visual hierarchy

The order in which a reader preceives the elements of a map.

Balance, arrangement, negative space, symbols, etc.

The visual hierarchy is established by the cartographer’s choice of…

Visual center

About 5% higher than the geometric center. Maps centered on geometric center may feel “heavy".”

Rule of Thirds

The guideline is used to compose and crop photographs but also works for maps. Place important items at the intersections of lines dividing the page into thirds.

Alignment

Place elements in ordered columns rather than a haphazard arrangement. Align edges of boxes exactly using guides and snapping.

Balancing elements

Avoids crowded or open areas. Uses negative space as a design tool to seperate or combine elements more subtly than neatlines.