STEP 2: Assigning the work
Assigning the work
Assigning the work to your group can be done in two ways. The first method is to assign work by theme or feature, say a quota of infrastructure to trace (i.e. 50 buildings, and/or 50 roads per student). The second method is to assign work by geography. One can assign designated cells (bounding box) to each student, or, a combination of both of these methods.
The creation of cells is done through OSM Tasking Manager (OSM TM) and is explained in the next section.
TeachOSM Tasking Manager
In addition to the OpenStreetMap website, we make use of a tasking tool called TaskingManager. The Humanitarian OpenStreetMap Team (HOT) developed the Tasking Manager as a tool to coordinate collaborative mapping efforts for disaster-affected areas.
A TeachOSM instance of the tasking manager has been deployed to allow for similar collaborative efforts in a classroom setting. Class instructors will need project manager rights on the TeachOSM TaskingManager website to set up a “task” or assignment. Setting up a task will involve outlining the study area, segmenting the area to be mapped, and assigning these segments to students. Visit the TeachOSM TaskingManager site to explore the tool. and to request administrative rights. To request project manager privileges, please email email@example.com
We will go through this tool in detail in the following section.
Working with the Tasking Manager
Once you’ve determined your study area, you’ll have to create a new “task” in the TeachOSM TM. This task will provide the students with geographic location, cell assignments and instructions.
Step Go to TeachOSM TaskingManager and log in using your OSM credentials.
Step Under your username, select ‘New Project’
Three You will now see the job creation interface:
Step 4 You will be given the option to draw your study area freehand, or, to import a GeoJSON or KML file (we will proceed with the “draw” option for our demo)
Step 5 Zoom to the location of your study area (this takes a little time and practice), once satisfied with your position, click on the “Draw” button, and draw a boundary around your study area.
Step 6 You must decide if you want the task to be divided into regular grid cells, or irregular geometries
Step 7. Choose your cell or tile size from from the selection bar (the default is medium). Sizes range from extra small to extra large (XS - XL). XL covers more area per tile and XS covers less area per tile. Avoid creating very large tiles. Smaller more manageable tiles are potentially less daunting to students and break the area of interest into more manageable chunks.
Step 8. It is important to populate the task with a a job description (a backstory to the mapping project), and specific instructions for the participants (like what items need to be traced; roads, rivers, buildings etc.) - even if this a reiteration of information already presented in class. This space should include perhaps include a note stating the task was created as part of a class project and ask those not involved with the class to refrain from editing in this area.
Sample Task Description for the Tasking Manager
As you walk through the task creation, you will be prompted to create both your task description (a backstory to the mapping project), and specific instructions for the participants (like what items need to be traced; roads, rivers, buildings, etc.)
This is a sample task descrition:
This is a simple sample of task instructions:
There are also tabs to include extra information, such as specific imagery sources (other than Bing), identification of priority areas, and designation of specific allowed users. Information for these tabs is optional.
Keeping the work equitable
There are two key things to keep in mind while assigning the work, these are; equitable division of labour and sufficient time for completion.
There are two main ways that we assign a tracing “quota” to our students
1) Assign a specific numbers of “nodes” to be traced, (let’s say 1000 nodes)
2) Use the “assigned cells” method built into the Tasking Manager
Assiging a node quota
This is a very precise way of defining equitable work within an OSM task. Each student is asked to capture a specific number of nodes within a given study area. Assignments vary, depending on the level of experience, and the complexity of the task. We have featured anything from 1000, to 2000 nodes as part of a tracing assignment for an undergraduate GIS class. For example, each student was expected to trace 2000 nodes. This node count consists of buildings and roads, and which were to be completed within 2 weeks of training. The assignment was worth 10% of a university level class in GIS. The syllabus featuring this assignment, and the specific assignment description can be found on this Syllabus page.
Students perform their tracing as usual within OSM, then check on their work periodically to determine their progress. We have found that the best way for students to keep track of their individual quota is to use Overpass Turbo (we will provide more information on how to use Overpass Turbo for both monitoring and grading in a later module).
Assigning specific cells
Using the “assigned cells” method will require additional work on behalf of the instructor as they must determine the difficulty level assocated with each cell. This workflow will involve checking out, and evaluating each cells individually. Instructors must then assign each individual cell to a student (students must have an existing OSM account for their name to appear in the list - see .gif below).
Instructors can set a high/medium/low designation on the density/difficulty level for each cell, as some cells will have more traceable infrastructure than others.
Students will have to create their OSM account well in advance of the assignment. Google forms is an effective way to collect this informtaion.