A note on Task Abstraction

by Mike Gleicher on September 23, 2017

This came up in class today, after class today, and in other conversations, so I thought I’d mention it. I tried to make this point in the lecture, but probably wasn’t clear enough.

There are many ways to think about task abstraction. What Munzner gives us in her book is just one way. One thing that the book chapter doesn’t do as well as the paper (that the book chapter is based on) is to give the perspective that there are many other task taxonomies and ideas on how to do task abstraction out there.

The taxonomy that Munzner presents in the chapter makes it seem like all tasks fall neatly into the nice little boxes (categories), and that those category names are something fundamental. I wish it were that simple. There are many ways to divide up the world of tasks. And each way has its good points and bad points.

So don’t get stuck on trying to figure out all of Munzner’s categories, or try to shoehorn any real task into exactly one of the boxes. View them more as food for thought. Sometimes it is useful to know if someone is trying to “enjoy” their data (as opposed to hating it?). Sometimes it is useful to distinguish browsing from exploring – not that the words are important, but that the idea that the viewer may or may not know where to look can be relevant.

Yes, even I have gotten into the “defining a different way to abstract tasks” game. If you’re curious, it’s part of my recent paper on comparisons.

The Week in Vis: Week 4 (Sep 25-Sep 29)

by gleicherapi on September 23, 2017

Week 4 (Mon, Sep 25-Fri, Sep 29) – Encodings

This past week we looked at abstraction – of both data and task – as a way to analyze visualizations, and as a way to analyze problems to try to map them to visualizations. We also played with Tableau a little bit, both as a way to show how abstraction to encoding mappings can work, but also to see it as a tool you might want to try to use for DC1. On Friday, you had the opportunity to bring your own data set for DC1.

This coming week, we’ll look at encodings more carefully. We’ve already been talking about them, but in the readings and class discussions we’ll try to dig a little deeper into what makes for a good encoding, what choices are available for encodings, and why we might want to prefer one encoding over another. In Wednesday’s class, we’ll try another in-class design exercise (bring color pencils/pens).

For this week, Friday is not optional – we’ll use it as a way to talk about Visualization research. And in particular my visualization research (I’ll use it as a chance to plan my talk at the Vis conference the next week).

The following week (October 2-6), there are no class meetings – but everything else will happen (Reading, Discussion, Seek and Find, Design Assignment).

Learning Goals (for this week)

  1. Appreciate encodings as the building blocks of visualizations, and see how they are put together to make visualizations.
  2. Know the range of different encoding choices (the visual variables)
  3. Have a sense of what each visual variable is/is not good for
  4. Understand how visualizations can be assembled from (and analyzed into) encoding choices.
  5. Assess standard designs in terms of their encodings and data abstractions
  6. Appreciate the need for ways to make good choices about encodings
  7. (probably not time to get to it) See how glyph design is a good testbed for putting encodings together.

In the optional class today…

by Mike Gleicher on September 22, 2017

Since it was optional and some people didn’t come…

We approved a number of new data sets for Design Challenge 1. You can see them on the list.

We talked a bit about the spirit and requirements for DC1. Nothing that changed the assignment at all.

There was a discussion of how the assignment related to what we’ve learned in class (I’ll argue it does). Which lead to a potentially more interesting discussion of Task Abstraction (the most interesting was actually after class with 2 students). I will probably make a posting about it later.

Laptops and Other Screens in Class

by Mike Gleicher on September 20, 2017

Short version: If you use a laptop (or other device) in class, please be mindful that you may be distracting others.

There are many very legitimate reasons that people use laptops and tablets in class.

However, screen can be really distracting to the people around you. All those things designed to catch your eye are also catching the attention of others. In fact, some of the readings might help you appreciate this. Much web content is designed to attract the human eye. Whether it is on your screen or someone else’s. Things like bright colors and motion are particularly hard to avoid since the visual system is very sensitive to them in the periphery.

And, if you’re doing something that is not class related, that makes matters worse. It’s one thing for you to decide that you want to be distracted. But if you’re preventing others from learning by distracting them, that’s really bad.

I don’t want to try to restrict what people do, or even define what “legitimate class related use” is. But, I do ask that people try to avoid doing things that may be distracting to others. And generally be thoughtful about the people around you. They can see your screen. They can see your reactions to what is on your screen.

If this continues to be a problem, I will take some action. But for now, I am hoping that making people aware of the problem will improve the situation.

 

Some help with Excel

by Mike Gleicher on September 20, 2017

Can you use Excel to do Data Analysis for non-trivial things?(like DC1)

Yes, actually. Even more if you learn some of its fancier features.

Last year, Alper (who was TA) gave in class tutorials on how to do data analysis and vis with excel and Tableau. He is much better with those tools than I’ll ever be.

He wrote up the guide for excel. It specifically designed to help students in this class for DC1. It was meant for the in-class demo, but it is useful on their own. I find it really interesting to see some of the things that can be done easily in excel.

Design Challenge 1 was Posted

by Mike Gleicher on September 20, 2017

In order to keep the “News” page clear, the Design Challenge 1 postings were made in another category. If you haven’t seen them, the main description is here. A page describing data sets is here.

The Week in Vis: Week 3 (Sep 18-Sep 22)

by gleicherapi on September 16, 2017

Week 3 (Mon, Sep 18-Fri, Sep 22) – Abstractions

This past week, we looked at the broad question of “why use visualization,” talked about some historical examples (and Tufte), and did some practicing with critique.

This week, we’ll deal with the topic of abstraction. Which is really two topics: Data Abstractions and Task Abstractions.

On Monday, we’ll have a lecture on abstraction. We’ll also do another critique practice.

On Wednesday, we’ll have a mix of things. We’ll talk a little bit about the first Design Challenge (which should be assigned this weekend – keep your eyes open). We’ll talk a bit more about Tableau both because it may be useful for the first design challenge, but also because it makes use of some of the abstraction concepts (which is why it’s in a reading). And we’ll do an in-class exercise to make sure everyone has a good sense of data abstraction.

On Friday, there will be an optional class to talk about Design Challenge 1 – in particular, if you want to bring your own data set, this is your chance to get it “approved.” (this will make more sense once you see the rules for the assignment)

Learning Goals (for this week)

  1. Understand the value of abstraction in visualization design
  2. Have a sense of task abstraction, it’s value, and it’s limitations
  3. Understand data abstraction, and what it means for creating appropriate (and transferable) designs.
  4. Get some encoding basics and see how basic visualization designs come from attaching data variables to visual variables

Getting Tableau

by Mike Gleicher on September 14, 2017

Tableau has generously provided their software for students in this class. The details on obtaining it are on Canvas – note that this is only for student in class this semester (I’m using Canvas as the mechanism to only make it available to students).

Using Tableau is optional, but it is an interesting tool, it may be useful for some of the assignments, and you can learn a lot about visualizations by trying to do things with it (it embeds a lot of knowledge about how to make good visualizations and tries to guide you).

However: Tableau provides free licenses for students that ask. You can apply for a student license on their web page. This may be better than using the class license, since it may last longer (it’s not clear how long the class license will last after class).

The Week in Vis: Week 2 (Sep 11-Sep 15)

by gleicherapi on September 8, 2017

Last week, we got started with some introductory material and a simple design exercise. If you haven’t done last week’s readings&discussion and seek and find, please do those immediately! It’s important that you do them – it’s more than just making sure the class mechanics work.

This week, we’ll have a more regular schedule with class meetings on Monday and Wednesday, and a reading with discussion (first post due on Tuesday), and a seek and find (due on Friday).

The basic topic is to get some foundational perspective on visualization by asking the question “Why” (do visualization, does visualization work, …). We’ll also talk about critique and practice it a little.

Hopefully, all of the enrollment issues will settle out and we’ll figure out whose in the class and who isn’t.

Learning Goals (for this week)

  1. Appreciate the range of reasons why visualization is useful.
  2. Get a perspective on key foundations (perceptual, cognitive, task effectiveness, …)
  3. Get some historical perspective on visualization
  4. Begin to think in terms of task
  5. Understand what effective critique is and how to do it.

If you missed class today (Friday, 9/8)

by Mike Gleicher on September 8, 2017

Some people may have missed class because they didn’t enroll yet. Or didn’t pay attention to the web site that said that this week Friday is no optional. Or, you just had something else to do.

But, if you missed class (and please, try not to miss class in the future)…

The slides from lecture are on Canvas.

The in class excercise is from:
45 ways to communicate 2 numbers

Try to generate as many ideas as you can before looking at the 45 he provides.
Then try to see if you can categorize and describe the different designs. You should try to do the exercise on your own – you don’t need to send me your answers! You missed out on some creative designs from your classmates, and some discussion of what this tells us about how to think about visualization.

Also, be sure to read through the “How to Visualize” on the course web (since we’ll talk about the 4 step process), and the 4-design moves example.