A Cartesian Graph interaction presents a graph on which the candidate may plot points, lines, rays, line segments, circles, and polygons. A graph and tools are provided to the user.
You may customize the graph to change the increments or add a title and axis labels. You may also choose to display only certain graphing tools.
Creating a Cartesian Graph Interaction
- In the item editor, click the plus sign and click Stem. This displays the Select Interaction Type window.
- Click the Graphing tab to reveal graph-based interaction types.
- Select Cartesian Graph, then click Create Interaction.
- Add content to your stem prompt (ex: "Draw a ray whose end point is ...").
Indicating the Correct Plot
Draw the correct plot that you expect the candidate to draw. Use the Graphing Tools to draw. For example, to plot the correct answer for the example shown above:
Click the Ray tool:
Click on the end point (2,3). A point is plotted.
Click on the point (4,6). A second point is plotted and the ray is shown.
Customizing the Graph
If you want to change the appearance of the graph or control the tools made available to the candidate, click Customize.
The Chart Editor appears.
Make changes using the options available. Click Update Chart Preview to see how the changes will look.
When you are finished editing, click Close.
Erasing a Plot
If you need to erase a plot you created on the graph, click on the Erase icon.
Hover over the plot you want to erase. It highlights in red.
Click on the plot to remove it.
Repeat this process for each plot you want to remove.
By default, the candidate receives 1.00 point for drawing the plot(s) correctly. You can, however, choose to give 1.00 point to a candidate if they get any part of the plot correct. For example, if they need to plot a ray with a certain end point, they could get full credit for just that.To give credit for certain aspects of the plot, click the "Type" drop-down menu and choose Scoring (Custom).
Options such as the following appear:
Check off properties of the plot that should receive full credit. For example, for this ray, if BX and BY are checked, the candidate receives full credit if they at least get the end point for the ray correct.
Adding Background Plots
If you need a plot that displays on the graph but is not scored, choose "Background" as the type option within the scoring section.
The plot turns gray on the graph. You may optionally allow a label on the plot.
Tip: Use the "background" option to show the candidate something on the graph which they are to mimic or work with. For example, an item may ask the candidate to plot the reflection over the x- or y-axis of the shape that is shown.