Optimizing for Frequency - Quantitative Research in UI Design
– posted April 19th, 2007 by Des Traynor No comments
Firstly I’d like to take the opportunity to welcome our newest employee onboard –me.
I’m Des Traynor, formerly a contract lecturer and still a PhD student in NUI Maynooth, co-creator of Bigulo.com, and writer of the light-on-dark ego-trip DesTraynor.com. I joined iQ because it’s a company full of great people doing excellent work. After two days in the job that much is certainly clear. Now, onto the content …
Mixed method research is essential in Usability Design and Analysis, as it is in most sciences involving human factors. This post discusses quantitative research methods. i.e. how we generate meaningful data that informs us of the actual tasks users perform, and presents one simple place that they can be used to greatly enhance a website.
Frequency of Use Dictates Priority
You might not have heard of Huffman Coding before, so here is a crash course. Huffman coding is an algorithm stemming from Information Theory that compresses data by encoding it in such a way that the most frequently used information has is heavily compressed. As a trade-off the remaining, rarely used, information is only mildly compressed.
Huffman coding analyses the data stream, looks at the most frequently occurring letters, and assigns them very short symbols. For example if you’re encoding English on a letter by letter basis, e or t might have a short encoding of 01, whereas v,x or q would have long encodings like 110101 or the like. As a result the word “the” would be heavily compressed, whereas “quizzical” would be barely compressed at all.
Interface design is similar, you use a good Web Analytics tool to find out what are the most frequent tasks performed, and you make sure that their “encoding” is sufficiently short. Encoding in this domain corresponds to mouse clicks, or home page prominence.
Uses of Dynamic Navigation
Some sites are clever enough to automatically monitor the frequencies of actions performed and will have offer Goal Based Navigation in complementary combination with the natural website hierarchical navigation. This is rewarding, as it means your website can adapt to “flash-in-pan” irregularities.
For example, claiming a government discount on bottled water due to pollution is probably not a day to day for most users of a council’s website. As a result that article might be 4 clicks deep in the website. Then one day RTE mentions the phrase cryptosporidium and now it’s everyone top priority when visiting the site, but it’s still 4 clicks deep. If all the navigation is static, this means changing the website to cater for these new one-off visitors. However, if you use Dynamic Goal Based Navigation, the relevant article floats to the top pretty quickly meaning that the most popular article is now one click away. That’s the user experience you should be aiming for!
That is just one way of using Quantitative methods for informing interface design, and quantitative research is only one part of what we do. If you think you or more importantly your visitors would benefit from analysis such as this, Come talk to us.
I’ll write about the Qualitative research involved in UI design some other day, but if you can’t wait, I’d recommend About Face 2.0 by Alan Cooper.
Sample Scenario
Here is something to think about, if you were to design ATM software, how many screens would you use, given that 98% of the actions at an ATM are withdrawals, and only 20% of people want receipts. Is it just me, or is ATM software the most broken backward nonsense that we deal with on a day to day basis? Can you imagine this conversation in reality…?
- AIB Clerk: Hi, what can I do for you?
- Me: I’d like some money please.
- AIB Clerk: Okay, we offer €20,€30,€40,€50,€60,€80,€100,€200 or Other.
- Me: 30 Euro Please.
- AIB Clerk: Sorry, we don’t have the notes required to give you €30. Do you still want money?
- Me: Yes.
- AIB Clerk: Okay, we offer €20,€30,€40,€50,€60,€80,€100,€200 or Other.
- Me: 40 Euro Please.
- AIB Clerk: Sorry, we don’t have the notes required to give you €40. Do you still want money?
- Me: *SMACK*
Later, that same evening …
- AIB Clerk: Okay, we can give you €100, to protect the environment we do not normally provide receipts. Is this okay with you?
- Me: Yes.
- AIB Clerk: Sorry you appear to have entered your PIN incorrectly, please try again.
- Me: ****
- AIB Clerk: Hi, what can I do for you?
What is the optimal number of screens for ATM software? I’m pretty sure it could easily be reduced to just 1. Any takers?
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Categories Usability, Web analytics
