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I'm currently working on a DPhil in HCT at the University of Sussex. This section of the website is for an on-going 'learning diary', for me to write my thoughts and notes on various courses and my thesis.


Seminar 1 - the intro

HCCS Advanced topics is the second course I am taking this Autumn. It's not really obvious from the title of the course what that covers! It's an entirely seminar-based course, and is the first one to have an exam rather than written reports.

After the first seminar it seems that the 'advanced' bit comes from looking at the current research boundaries and focus areas in HCI. Apparently each week we'll be given an academic paper to read, then two students will lead a group discussion about the contents. Sounds quite interesting. It seems that we'll be looking at Universal Usability (or Accessibility?) as a general theme throughout the course. And we get to build some phidgets apparently, so that should be good. I'm a little worried about timing again though. We only have 5 weeks from start to finish for that project, and it's group work. Going to be tight I think. Although it might help us keep our focus for a short period. I think a lot of it will depend on what we have to do and try to build.

Our first homework is to look up universal usability and find some of the key players and ideas in the area. I think Julie Howell'spresentation at the last Geek Girl Dinner might be a starting point. Time to do some research!


Lecture 2 - light and vision

What sort of frames per second is needed for perception of smooth movement? In the UK, TVs refresh at 50 Hz (60Hz in the US). Apparently the picture only gets changed every other cycle, so that's 25 frames per second. Film is apparently 24 frames per second (which apparently causes some issues that we'll revisit in a later lecture... Should come back and link when we do!). Apparently at 20 frames per second you start to notice jerkiness, and 15 frames per second looks really jerky (I'm sure that could be a useful thing to know if you wanted that kind of effect).

A brief refresher on electromagnetic radiation (of which visible light is a tiny range in the middle):

wavespeed (in this case c) = frequency x wavelength

Visible light has a wavelength of between 400nm (blue) and 700nm (red). That's tiny, but there's still a huge difference in the wavelength of blue light compared to red. That makes it difficult to focus on red and blue at the same time (would it be easy if the wavelengths were  exactly double?). It also explains the sky being blue apparently, because the shorter wavelength of blue light means it's much more easily scattered, whereas the longer wavelength light comes straight to us from the sun. The sun therefore looks a lot more orange from Earth than it does from space (where there's no atmosphere to scatter the light!). And when the sun sets the light has to travel through more of the atmosphere, so longer wavelengths get scattered. Therefore the sky takes on the different colours, and the sun gets more and more red as the range of wavelengths that comes straight through to the eye gets smaller.

The sensors in the eye are split into two types - rods (which respond to light and dark) and cones (respond to colour). The cones are concentrated where we focus, while our peripheral vision is more dominated by the rods. At night the cones stop working (they need high light levels) so our night vision is dominated by the rods, which means you can often see things in your peripheral vision that you then can't see as clearly when you focus on them.

Rods react to a frequency range that overlaps mostly with blue and green. They do not respond to red light particularly. This can be useful for (for example) dials on a ship, where the dials can be displayed in red for the cones to pick up on, without disturbing the rods 'night vision' that can be maintained for looking out for things like iceburgs(!).

The primary colours are defined by the cones in the eye. The cones are responsive to three different frequencies. Blue, green and red. Apparently fish only react to blue and yellow, but on leaving the primordial soup it became more useful to split out the yellow into green and red. Because this is a relatively (in evolutionary terms) recent development red-green colourblindness is still fairly common.

The primary colours for active displays (those that create the light - e.g. monitors) are therefore red, green and blue. Passive displays work by reflecting light, showing colours by absorbing the other wavelengths. The primary colours for these are therefore cyan (absorbs red light), magenta (absorbs green light) and yellow (absorbs blue). This gives rise to the CMYK colour value (with K being for blacK - the pigments in ink being not sufficiently good to generate pure black so a separate cartridge is needed).

I need to do some follow up research on colour gamuts, because I wasn't entirely clear what the graphs he was showing us represented, or what the axes stood for. Meant to ask, but the queue of people waiting to talk to him was a little off-putting. I'm sure there are some resources out there!

The other way of measuring a given colour is to represent it as the chromacity (the colour defined by the main frequency of the light) the luminosity and the excitation. Saturation and brightness I think, but again, need to follow up on that.  


Lecture 1 - the overview

A new term, and the first optional course I get to take! The full title is Multimedia Design and Applications, and it's being taken by Dr Paul Newbury. It's a combined 3rd year undergraduate and Masters level course, with most of the difference being in the level of detail in the assessment. I find that slightly odd, but it seems to be a fairly common thing at Sussex. I guess it's something about self-learning or something like that.

It sounds like it's going to be an interesting and useful course. I can already see where it might have helped with some of the work I've done over the last year. The understanding of compression for images and videos would have been handy, and soem general multimedia design ideas is always going to be handy!

Warning! Danger Will Robinson! This may suck much spare time! The assessments are creative and of a nature that there will always be something more that could be done. Careful management of time will be needed!   

There are two different focusses on computers for multimedia - development and delivery. Generally speaking the development tools are expensive, whilst the delivery of the content is free. But there are problems to overcome with the delivery (for example, playing videos through PowerPoint via a projector).


Looking back

I've been looking through this blog in preparation for handing it in tomorrow. It's really interesting to look back at what we've done, and what my thoughts have been along the way. I feel like I've done a huge amount of background reading, although some of this has been driven by the work project as well as the course, and it's been fantastic the way the two have fed into each other.

I really feel that I have a much better handle on the process of conducting user research now. Which is obviously good, because i'm going to need it to plan what we do for the next 4 months at work! But it's good to feel that some of the frustrations I felt in my last job (where I could see that the software we were producing was wrong and ugly, but had no framework or language to say why or what we should be producing) are going away. I think I have gained an important toolset, and look forward to being able to practice using it.



We presented our report today. Done!

Quite a stressful day. Although we met last Thursday to combine everything and get the presentation structure sorted, we still had to make sure we were going to be within the 10 minute time limit. We also had to get everything printed out and bound.

Getting within the 10 minutes was tough. We felt we'd got the structure right, with a brief overview of our demographic and the techniques we used, then spending most of our time on our findings and recommendations. And we did cut it down to 10 minutes, although perhaps we rushed it a bit to try and fit everything in. It got a bit stressful cutting it down too - we're all so tired that it was difficult keeping tempers and doing it again and again and again, and it was really hard to make suggestions that didn't come out as criticisms of the points.

Watching the people we were presenting to and listening to the other presentations, I'm pretty sure our balance was right. The clients were more interested in the recommendations than the methods etc. I think we should have made more positive points about the webpage to make it more agreeable, but our 10 minute limit meant we'd have had to have sacrificed something else, which would have been tricky. It was very frustrating to hear most of the other groups going well over 10 minutes, given how hard we'd chopped at ours to get within it.

Definitely a relief to have it done though...