Graphics: May 2009 Archives

Why I Avoid Labeling Arrows on my Concept Maps

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I'm actually a big fan of diagrams (maps, family trees, bar charts) but I've always found the standard concept map (like the one below from Wikipedia) a little confusing

Concept map of Concept Map
Click Image to Enlarge

This is one of those concept maps where all the arrows are labeled with the relationship. Someone asked a linguistics group if they felt that the arrows should be labeled or not, and I do say not, but maybe not for linguistic reasons.

Normally when I create a diagram, I don't label relations per se, but just for a mini experiment, I redid a concept map in two versions, one my way and one like a classic concept map, labels and all. I noticed some things that made me understand why I don't like to label arrows/lines.

  1. The big one is that I think that I (and most natural map readers) are trained to infer relationships from the connecting lines/arrows. Only the labels on the objects matter. The labels on the arrows are redundant.
  2. Not just redundant, but distracting because they take up space in the diagram and interfere with my ability to process the concept map as a whole architecture. This is important for a diagram like a family tree where you track lines to find your first cousin.

  3. Not just distracting, but conflicting. In the Wikipedia concept map (of what a concept map is), the arrows are the same, but the labels may differ. I am receiving conflicting input on whether the relationship is the same or different.
  4. I'll also note that there is a conflict in classic concept maps on whether shapes change depending on object properties. Normally I assume that if a shape has the same format, it's the same kind of object. But if labels are different, I can't make that assumption. Do I have to infer from the text? and how?
    P.S.: I did find an example with different shapes but arrow labels. I think the shape cues makes it much easier to understand what's happening.

I have to say that not all concept maps have labels on their arrows

At least I am not alone on this one. I am curious if that person was able to complete the research on arrow labeling....

Post Script

The link from D. Stong goes to a research paper describing the "rules" for making a concept map including the labels on the connections. It may be good theory, but I'm still not sure about the design aspect.

ALT Tags without Tears?

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I've been talking a lot about accessibility recently, but the one thing I have utterly failed to convey is that it's not as scary as it sounds. Sometime it can be relatively painless if you just know the right trick.

So I am going to switch up strategies and talk about some tips and tools I have found that make my accessification task easier. The first up is the infamous ALT Tag for images

ALT Tags "Reconceptualized"

The term ALT tag implies a scary HTML tag, but maybe it's better to think of it as a caption to use if it doesn't download. That is, if a user can't access the image (i.e. it doesn't download correctly or it's not visible), then the browser reads an alternate description.

Depending on your connection, I think we've all experienced a missing image for button or link, so wouldn't it be nice to know what it's supposed to be? VoilĂ  the ALT Tag

How to do it

You can insert an image ALT tag in many tools, even if you don't know any HTML, usually by just filling out a description field in the image upload process. See the links below for inserting ALT tags in different tools:

Work Flow

I admit that if your course (or Web site) uses hundreds of images, then it will be a chore to tag them all at once. So...I don't usually tag them all at once. Instead, I try to tag them in small batches as the course is being developed.

Two strategies I have used:

1. If I am working on a Web site, then I tag each image as I create each page. I actually use Dreamweaver a lot even if the content will end up somewhere else (e.g. ANGEL, Drupal). Because the Dreamweaver ALT tag option is basically a form field in the Properties window (or the initial pop I get when I insert the image), I really don't have to touch the code that much (other to batch change the URL).

2. If you are working in Word first but converting to the Web later, it may make sense to just type in an ALT tag below the image as you insert it. When it comes time for the content to migrate, then the ALT tag will be there to be cut and pasted.

I've been using this process for the last 5 years now, so I can say that most images are used have some sort of ALT tag, and I don't spend too much time...unless I forget to tag as I add.

I know there are times when people are batch loading images to a site (e.g. some photo sharing sites) where it is very difficult to add an ALT tag. But I really think that should be the minority case since images are often collected and processed over the course of a period of weeks. Maybe I'm missing something though. That's why I have a comments section.