Tutorial for designing a digitizing project

TUTORIAL FOR DESIGNING A DIGITIZING PROJECT

Created by Lesley-Ann Dupigny-Giroux at the University of Vermont to demonstrate the use of the CCTP units to create a resource that an instructor can use in their class. (See Lesley-Ann's CCTP Unit: UNIT 13 - Digitizing Maps)

This tutorial is designed to provide an example of the ways in which a series of units from the Core Curriculum for Technical Programs (CCTP) can be synthesized into a teaching exercise of varying lengths. The example given here is the creation of a digitizing project using Units 12-15 of the CCTP. The goal is the generation of a coherent series of tasks that students need to implement from the start of a digitizing project to its completion. Key questions/issues that need to be pre-determined by the instructor form the basis for the development of this tutorial.

STEP ONE - ROLE OF THE INSTRUCTOR

The instructor needs to predetermine:

digitizing goals to be accomplished (Unit 12 outlines some considerations in planning an entire digitizing project)
choice of digitizing software (if the GIS package doesn't feature a digitizing module)
map/image input format medium (large map, aerial photo etc.)
map preparation needed
type of digitizing required a) on-screen b) tablet
labeling to be attached a) while digitizing b) as a post-digitizing task
post digitizing tasks

STEP TWO - GOALS OF THE DIGITIZING EXERCISE

Digitizing goals to be accomplished may include one of the following:

introducing the students to digitizing (ideal for a two-hour laboratory)
setting the framework needed to allow the students to become competent in the tasks involved (ideal for an assigned exercise once the students have become familiar with the software and hardware)
rigorous development on the part of students of the entire digitizing project (ideal as an extended project involving a lot of repetition and attention to detail)

More details on the specific tasks to be accomplished at each of these stages can be found in the competency, awareness and mastery sections of unit 13.

STEP THREE - INPUT FORMAT

The source of the data to be entered will help to determine whether manual digitizing, on-screen digitizing or scanning is appropriate. For the various contexts within which the three techniques may be applied, refer to the links below.

CHOICE OF DIGITIZING TYPE

The choice between manual and on-screen digitizing will depend on the nature of the input medium as well as on the goals to be accomplished with the end product. For the advantages of on-screen digitizing refer to Unit 14, while Unit 13 discusses the techniques of manual digitizing.

STEP FOUR - MAP PREPARATION

Regardless of the type of digitizing to be performed, map preparation is crucial in the reduction of unnecessary repetition of tasks, as well as helping to ensure an accurate end product. In addition to the list of predigitizing tasks outlined in Unit 13, other key decisions include:

identifying the section of the map and exact locations of features to be digitized
determining a method by which to keep count of the features already completed
allowing the map/medium in question to adjust to the room's temperature and humidity before taping it to the digitizer

STEP FIVE - ATTACHING LABELS

The usefulness of the spatial data entered via digitizing or scanning will be a function of the attribute data attached. This labeling can be done while digitizing (for students who have mastered the basics) or as a separate exercise as outlined in Unit 15.

STEP SIX - POST-DIGITIZING TASKS

In order to ensure an accurate end product, a number of issues must be addressed. These include the identification and elimination of errors, coverage editing and labeling (if necessary). These are outlined in Unit 13.

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Currently maintained by Steve Palladino
Created: October, 1998. Last updated: November 16, 1998.
Content comments to Leslie-Ann Dupigny-Giroux
Formatting comments to Steve Palladino