Thanks for joining us for Week 14 of Workout Wednesday – Power BI Edition. This week we are going to make accessibility improvements to an existing report to make the report more usable. There are no dependencies on prior weeks for this workout, so feel free to jump right in.
When we create reports, we need to consider that our end users may not consume information the same way we do. Some people have color vision deficiency, making it difficult to distinguish certain colors. Others may have low or blurry vision. Some people may use a keyboard instead of a mouse, and others navigate using eye tracking software. While it may be obvious that we should design Power BI reports for visual accessibility, we should also be aware of cognitive accessibility and motor accessibility.
According to COQUAL, about 30% of white collar employees in the United States has a disability. 62% of those employees with a disability have the invisible kind, so it isn’t obvious to others just by looking at them. And they might not tell you about their disability or request accommodations because at least a third of employees with a disability have experienced discrimination or bias in their current workplace.
This week, we are going to take a report from a previous challenge and make a few changes to make it more accessible. You might not see a big visual difference in the report when you are finished, but it will be more usable for people that have low vision or that use screen readers or keyboard navigation. Hopefully you will see that small accessibility tweaks can make a big difference. Note that this week’s requirements do not include all accessibility considerations – for a more complete list, see this blog post.
- Download the starter Power BI Desktop file here. It is the Summary page from the week 3 workout. If you prefer to use your own week 3 file, feel free to do that.
- Measure the color contrast ratio of the line in the area charts and the bars in the bar charts against the background. Adjust the visual colors as needed so they have a color contrast ratio of 3:1 against the background. https://contrastchecker.com or Colour Contrast Analyser may be helpful for this requirement.
- Measure the color contrast ratio of the text in one card, one area chart, and one bar chart. Adjust the text color of all the cards, area charts, and bar charts as needed so it has a color contrast ratio of 4.5:1 against the background.
- Add alt text to all non-decorative visuals on the page. Check out this Nightingale article if you need some inspiration for writing your alt text. When consuming a Power BI visual with a screen reader, Power BI announces the visual title, the visual type, and then the alt text.
- Update titles to be as descriptive and useful as possible. For visuals, that have the title hidden, add a descriptive title and then turn off the title. For example, the revenues area chart might be titled “Total Revenues by Year in USD, 2005 – 2017”.
- Set the tab order on the page so the page title textbox (NCAA Revenues & Expenses | Summary View) is first, the year slicer is second, and the Revenues card is third. The Revenues area chart should be fourth and the Revenues bar chart should be fifth. Continue this order with the Expenses and Profits visuals.
- Mark any decorative shapes or images (such as the line shape under the page title text box in the provided file) as decorative so it is hidden from tab order.
- Use keyboard shortcuts to navigate the report and do the following:
- Set the year slicer to 2017, review the report, and then clear the slicer selection.
- Select the SEC conference in the Revenues bar chart. Then navigate through the revenues area chart to the year 2007 and find the Total Revenues amount.
- Bonus: Try using Windows Narrator or Apple VoiceOver to understand the experience of using the report with a screen reader.
This week uses a data set that breaks down NCAA athletic department expenses and revenues by year. It is the same dataset that we used in weeks 1 – 4. Feel free to use your own version of week 3 or 4 for this workout instead of our file. If you didn’t participate in week 3 or 4, or just want to start from our file, you can find it here.
When you open the file, you may notice that there is a second report page containing resources. Please take a look for details on the source data as well as guidance on accessibility in Power BI.
After you finish your workout, share on Twitter using the hashtags #WOW2021 and #PowerBI, and tag @JSBaucke, @MMarie, @shan_gsd and @dataveld. Also make sure to fill out the Submission Tracker so that we can count you as a participant this week in order to track our participation throughout the year.