The objective of this activity is to teach your student how to quickly determine the shape and trend of a line chart. We do that by scanning the chart as quickly as possible. We explicitly want to avoid “getting lost in the weeds” by exploring one data point at a time. It is perfectly fine to explore each data point when appropriate. However, when a student encounters a new chart they should always try to “see the big picture” first.
Install SAS Graphics Accelerator for Google Chrome.
Arrange the computer speakers correctly. Your student and the two computer speakers should form an equilateral triangle. Make sure both speakers are pointing directly at your student. Also, if your speakers have a “balance” setting, make sure the balance is set so that sound is evenly distributed between the speakers.
If you don’t have external speakers for your computer, your student can use headphones or ear buds. In that case, make sure your student is wearing them properly so when sound plays in the left speaker they hear it in their left ear.
Place the keyboard in front of your student so they can “drive” and perform the steps defined below.
Tip: If your student is using a screen reader, SAS Graphics Accelerator will use the screen reader’s speech facility to speak data values within charts. If your student is low vision and does not typically use a screen reader, they may benefit from SAS Graphics Accelerator’s ability to self-voice. To enable that feature, open the SAS Graphics Accelerator popup menu in the Chrome tool bar, activate the Options button, enable the self-voicing feature on the Options page, and activate the save button on the Options page.
Open the stock chart for Amazon.
If SAS Graphics Accelerator is installed, you should see an “Accelerate” button in the bottom right corner of the chart. If you don’t see the button, install SAS Graphics Accelerator and refresh the page in Google Chrome.
Activate the “accelerate” button. That should open the “sonification view” in a new browser tab.
If your student is running JAWS or NVDA with the default settings, their screen reader should enter Forms Mode automatically. If that does not happen, press Tab or Shift + Tab to move focus to the chart and then press Enter to enter Forms Mode.
When focus is on the chart and Forms Mode is enabled …
Press V until you hear “scan”. That ensures you are in scan mode rather than explore mode. Scan mode enables you to quickly scan the entire chart.
Press D until you hear “normal”. That will ensure that speed is set to “normal” which is the middle of five speed settings.
Now, press Right Arrow once to play the entire chart from left to right. It should take about ten seconds to play the entire Amazon chart at normal speed.
Ask your student about the shape of the chart. Does it trend up or down? Is it flat? Is there a peak or a valley in the middle of the chart?
Invite your student to play the entire chart several times by pressing Right Arrow.
Now, invite your student to experiment with different speeds by pressing D to change the speed and then play the entire chart again by pressing Right Arrow.
Point out that sighted students can see the entire chart at one time. That allows them to quickly determine the shape and trend of the chart. The equivalent experience for students with VIB is to scan the entire chart as quickly as possible. It is perfectly fine to listen to the chart several times, if needed. It is also fine to temporarily slow down the speed for a specific chart so you can hear more detail.
Before you leave this chart, make sure the student sets speed to the fastest speed they can tolerate. Ideally, that will be at least “Normal”, “fast”, or “Fastest”.
Now, invite your student to explore additional stock charts.
As they explore each chart:
Tip: The following Google Chrome keyboard commands might be useful:
How can your blind student independently create stock charts for the companies they interact with on a daily basis? That’s the topic of another blog post.
Activity: Reading bar chars using fun facts about planets
Activity: Create and share a simple bar chart
Activity: Creating line charts from Yahoo finance stock market data
SAS Graphics Accelerator Tutorial #1: How To
SAS Graphics Accelerator Video Tutorial #2: Options
By Ed Summers