Week 2: Alt Text for Graphs/Charts
Posted: Mon Feb 26, 2018 10:27 am
Graphs can be really tricky to write alt text for, because they often contain a lot of technical data. We want to make sure we are taking the best approach possible, so we appreciate any information or feedback you can provide.
Questions about graphs/charts:
Question 1. What tips can you provide for clear descriptions of charts and graphs? Not just for these ones, but in general. Have you ever come across any bad alt text for graphs? What were they doing wrong?
Question 2. If the graph has a lot of data (for example, Graph A has a lot of peaks and valleys), is it best for the alt text to summarize the main “takeaways” from the graph? Or should the alt text depict as much detail as possible, even if it means that it will be a lot of text?
Question 3. What are the best ways to describe units of measurement? For example, for the word “seconds” in Graph B, do you prefer the full word “seconds” or the short form “s”?
Question 4. Does it make sense to include data in brackets after a label in Graph C? Or is it better to ‘set up’ the graph and describe how it is laid out before providing specific data?
Question 5. What other things come to mind when reading these examples?
Graph A alt text: A line graph indicating a negative correlation between per capita GDP/wage and real wage, with the two meeting in the approximate year 1547 at approximately 0.5 real wage and 1.5 per capita GDP/wage. The late 1700's indicates a peak in per capita GDP/wage and the lowest point indicated in real wage.
Graph B alt text: Three line graphs with corresponding data over 30 seconds of time. The top graph represents distance (m) over time (s), the centre graph represents velocity (m/s) over time (s), the bottom graph represents acceleration (m/s squared) over time (s). There are vertical dotted lines that run through the three graphs to highlight the span of time between 4 and 7 seconds as well as between 23 and 27 seconds (approximate values). In the top Distance graph, the distance in m rises steadily and levels at ~140m and 15 seconds. It then lowers steadily before leveling off at 25 seconds. In the middle Velocity graph, the velocity in m/s rises steadily to 15 m/s, levels off at 4 sec until 7 sec, drops steadily and reaches 0 m/s at 15 seconds, continues to drop steadily at the same rate until it reaches -15m/s at 23s, rises steadily until it reaches 0m/s at 27s and levels off at 0m/s until 30s. The bottom Acceleration Graph starts at 4m/s squared, remains level until 4s, where it drops instantly to 0 m/s squared, it remains at 0 until 7s then drops to -2 m/s squared where it remains until 23s. It then rises to 4 m/s squared, remains level until 27s, drops to 0 m/s squared and remains at 0 until 30s.
Graph C alt text: The graph portrays the preimperial (~125-160 metres square), Roman imperial (~200-300 metres square), and postimperial (~60-80 metres square) roofed house size.
Questions about graphs/charts:
Question 1. What tips can you provide for clear descriptions of charts and graphs? Not just for these ones, but in general. Have you ever come across any bad alt text for graphs? What were they doing wrong?
Question 2. If the graph has a lot of data (for example, Graph A has a lot of peaks and valleys), is it best for the alt text to summarize the main “takeaways” from the graph? Or should the alt text depict as much detail as possible, even if it means that it will be a lot of text?
Question 3. What are the best ways to describe units of measurement? For example, for the word “seconds” in Graph B, do you prefer the full word “seconds” or the short form “s”?
Question 4. Does it make sense to include data in brackets after a label in Graph C? Or is it better to ‘set up’ the graph and describe how it is laid out before providing specific data?
Question 5. What other things come to mind when reading these examples?
Graph A alt text: A line graph indicating a negative correlation between per capita GDP/wage and real wage, with the two meeting in the approximate year 1547 at approximately 0.5 real wage and 1.5 per capita GDP/wage. The late 1700's indicates a peak in per capita GDP/wage and the lowest point indicated in real wage.
Graph B alt text: Three line graphs with corresponding data over 30 seconds of time. The top graph represents distance (m) over time (s), the centre graph represents velocity (m/s) over time (s), the bottom graph represents acceleration (m/s squared) over time (s). There are vertical dotted lines that run through the three graphs to highlight the span of time between 4 and 7 seconds as well as between 23 and 27 seconds (approximate values). In the top Distance graph, the distance in m rises steadily and levels at ~140m and 15 seconds. It then lowers steadily before leveling off at 25 seconds. In the middle Velocity graph, the velocity in m/s rises steadily to 15 m/s, levels off at 4 sec until 7 sec, drops steadily and reaches 0 m/s at 15 seconds, continues to drop steadily at the same rate until it reaches -15m/s at 23s, rises steadily until it reaches 0m/s at 27s and levels off at 0m/s until 30s. The bottom Acceleration Graph starts at 4m/s squared, remains level until 4s, where it drops instantly to 0 m/s squared, it remains at 0 until 7s then drops to -2 m/s squared where it remains until 23s. It then rises to 4 m/s squared, remains level until 27s, drops to 0 m/s squared and remains at 0 until 30s.
Graph C alt text: The graph portrays the preimperial (~125-160 metres square), Roman imperial (~200-300 metres square), and postimperial (~60-80 metres square) roofed house size.