Back to in-person presentations

Today, I gave my first in-person presentation since the pandemic. It was awesome! I was talking about the study I performed with Nabeel Sulieman about data visualization in environments that use right-to-left writing systems.

I wrote about this study in the past [one, two]. Today, you may find the results of our study at I hope to be able to publish the video recording of this presentation really soon.

The delicate art of fine trolling

Photo by Pixabay on

I’m reading the a 1991 paper by Barbara Tversky that deals with the directional representation of time. One sentence in the paper interview says

“There does not seem to be strong universal cognitive associations of quantity or quality to left or right”

Whenever I make a similar statement in the context of data visualization, I frequently get a self-assured response “of course there is – smaller numbers appear on the left!”. To answer this remark, Barbara Tversky added a small footnote that says

“Anyone in doubt should consult politicians on both the left and the right.”

Photo by Pixabay on

So gentle, yet so powerful.

כוון הציר האפקי במסמכים הנכתבים מימין לשמאל

אני מחפש דוגמאות נוספות

יש לכם דוגמה של גרף עברי ״הפוך״? גרפים בערבית או פארסי? שלחו לי.

X-axis direction in Right-To-Left languages (part two)

I need more examples

Do you have more examples of graphs written in Arabic, Farsi, Urdu or another RTL language? Please send them to me.

Textbook examples

I already wrote about my interest in data visualization in Right-To-Left (RTL) languages. Recently, I got copies of high school calculus books from Jordan and the Palestinian Authority.

Both Jordan and PA use the same (Jordanian) school program. In both cases, I was surprised to discover that they almost never use Latin or Greek letters in their math notation. Not only that, the entire direction of the the mathematical notation is from right to left. Here’s an illustrative example from the Palestinian book.

Screenshot: Arabic text, Arabic math notation and a graph

And here is an example from Jordan

What do we see here?

  • the use of Arabic numerals (which are sometimes called Eastern Arabic numerals)
  • The Arabic letters س (sin) and ص (saad) are used “instead of” x and y (the Arabic alphabet doesn’t have the notion of capital letters). The letter qaf (ق) is used as the archetypical function name (f). For some reason, the capital Greek Delta is here.
  • More interestingly, the entire math is “mirrored”, compared to the Left-To-Write world — including the operand order. Not only the operand order is “mirrored”, many other pieces of math notation are mirrored, such as the square root sign, limits and others.

Having said all that, one would expect to see the numbers on the X-axis (sorry, the س-axis) run from right to left. But no. The numbers on the graph run from left to right, similarly to the LTR world.

What about mathematics textbooks in Hebrew?

Unfortunately, I don’t have a copy of a Hebrew language book in calculus, so I will use fifth grade math book

Despite the fact that the Hebrew text flows from right to left, we (the Israelis) write our math notations from left to right. I have never saw any exceptions of this rule.

In this particular textbook, the X axis is set up from left to right. This direction is obvious in the upper example. The lower example lists months — from January to December. Despite the fact the the month names are written in Hebrew, their direction is LTR. Note that this is not an obvious choice. In many version of Excel, for example, the default direction of the X axis in Hebrew document is from right to left.

I need more examples

Do you have more examples of graphs written in Arabic, Farsi, Urdu or another RTL language? Please send them to me.

Data visualization in right-to-left languages

If you speak Arabic or Farsi, I need your help. If you don’t speak, share this post with someone who does.

Right-to-left (RTL) languages such as Hebrew, Arabic, and Farsi are used by roughly 1.8 billion people around the world. Many of them consume data in their native languages. Nevertheless, I have never seen any research or study that explores data visualization in RTL languages. Until a couple of days ago, when I saw this interesting observation by Nick Doiron “Charts when you read right-to-left“.

I teach data visualization in Israeli colleges. Whenever a student asks me RTL-related questions, I always answer something like “it’s complicated, let’s not deal with that”. Moreover, in the assignments, I even allow my students to submit graphs in English, even if they write the report in Hebrew.

Nick’s post made me wonder about data visualization do’s and don’ts in RTL environments. Should Hebrew charts differ from Arabic or Farsi? What are the accepted practices?

If you speak Arabic or Farsi, I need your help. If you don’t speak, share this post with someone who does. I want to collect as many examples of data visualization in RTL languages. Links to research articles are more than welcome. You can leave your comments here or send them to

Thank you.

The image at the top of this post is a modified version of a graph that appears in the post that I cite. Unfortunately, I wasn’t able to find the original publication.