Moving Down the Road Trying to Lighten My Load: Performance Load (and taking it easy)

This is one of the posts of design that, I hope, will help to establish that good design is not just about images, Photoshop and Illustrator! I’m really enjoying the book that all of this is coming from (for those of you who are new to this blog, that’s Universal Principles of Design, Lidwell et al, Revised, 2010). I’ve not had the vocabulary to express a lot of what I’ve learned and that, of course, makes it very hard to communicate. This blogging process has really helped me to tie everything together – but this one is particularly important because it explains why we have to make the effort to manage the load that our students encounter in our courses.

Whenever you’re trying to achieve a goal, you’re going to have to expend effort – in terms of mental and physical activity. When the load gets high, the time it takes to get the job done increases but, regrettably, it’s not just the time it takes that increases – the possibility of error increases and the chances of success starts to drop away. If the load is manageable, then the time reduces, the possibility of error drops and you increase the chance of success. This is the performance load of a task and I suspect that this is one of the key problems in the preparation of a lot of teaching materials and support. There has been an attitude that some of what we teach can’t just be offered – that effort has to expended for the students to value it, or to show that they’re ready for the material. Without going in to too much commentary on this, because I think it’s an attitude that is often used as an excuse rather than a real philosophy, if this is the attitude, that there is an effort barrier, then this has to very carefully managed or the performance load is going to cause an unnecessarily high level of failure.

How easy was it to read that last sentence? What if I’d said “I’m not sure I agree with this, but if there is an effort barrier, we must manage it carefully. Performance load can increase to the point where failure may be inevitable.” Is that easier?

What does load look like for tasks? If it’s moving things around then our muscles come into play, our ability to physically interact with our environment. If it’s thinking then we have to use our cognitive abilities to identify and complete the task. Fundamentally, there are two type of load:

  1. Kinematic load is a measure of the physical activity involved – strength, number of steps, repetition of action, amount of force involved – to accomplish something. Not many teaching activities will have a strength-related load component (which is good, as it means fewer accessibility concerns) but any time that we introduce an activity that requires physical steps, we’ll reduce the kinematic load if we cut that number of steps down as far as possible. Allowing students to submit their assignments electronically reduces the requirement to print the work, staple it, and physically attend a submission place to submit it. Think about how many things could go wrong in that chain – everything from paper out in the printer, to a water leak destroying all of the paperwork once it’s submitted.
  2. Cognitive load is how much thinking we’re going to have to do to achieve our goal. How much are you expecting someone to remember? Most people can only hold a few things in their heads at one point – fighting this is pushing water uphill. Keeping your concepts clear and your explanations simple can really help with this. Keeping your presentations simple stops people having to filter out things that aren’t relevant – use consistency in your materials and, if you’re trying to keep everything accessible, consider producing separate sets of material so that information that is useful to one group isn’t considered ‘clutter’ to another. (If you want a good example, look at subtitled movies. One subtitle is okay, but I’ve seen movies subtitled in Chinese characters, English and Tamil simultaneously. It leaves about half the screen for the content and makes the film hard to watch!)

However you reduce performance load, you have to remember that there will be a minimum load – assuming that you don’t change the requirements of the task. This can be easy to get wrong. Abuse of load reduction can be prevalent in students. If you consider plagiarism, this used to much harder than it is now that we have networked computers and the Internet. The cognitive load reduction of copying was still quite high, but it required an equivalent amount of kinematic load because of the requirement to rewrite the work (or type it in again from a print-out). So, just being aware of load reduction is only part of the battle – how we reduce performance load has to be considered while still understanding that we can’t reduce the requirements of the task itself.

I think this is what people are always suspicious of when we talk about design – that somehow considering design will demean, cheapen or over-simplify the task. I agree that this is something we should think about, but I certainly don’t think that it’s inevitable.



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