Why light text on dark background is a bad idea
As this is a suggestion which comes up quite regularly, I felt it valuable to document some of the research I have collected about the readability of light text on dark backgrounds.
The science of readability is by no means new, and some of the best research comes from advertising works in the early 80s. This information is still relevant today.
First up is this quote from a paper titled “Improving the legibility of visual display units through contrast reversal”. In present time we think of contrast reversal meaning black-on-white, but remember this paper is from 1980 when VDUs (monitors) where green-on-black. This paper formed part of the research that drove the push for this to change to the screen formats we use today.
However, most studies have shown that dark characters on a light background are superior to light characters on a dark background (when the refresh rate is fairly high). For example, Bauer and Cavonius (1980) found that participants were 26% more accurate in reading text when they read it with dark characters on a light background.
Reference: Bauer, D., & Cavonius, C., R. (1980). Improving the legibility of visual display units through contrast reversal. In E. Grandjean, E. Vigliani (Eds.), Ergonomic Aspects of Visual Display Terminals (pp. 137-142). London: Taylor & Francis
Ok, 26% improvement – but why?
People with astigmatism (aproximately 50% of the population) find it harder to read white text on black than black text on white. Part of this has to do with light levels: with a bright display (white background) the iris closes a bit more, decreasing the effect of the "deformed" lens; with a dark display (black background) the iris opens to receive more light and the deformation of the lens creates a much fuzzier focus at the eye.
Jason Harrison – Post Doctoral Fellow, Imager Lab Manager – Sensory Perception and Interaction Research Group, University of British Columbia
The "fuzzing” effect that Jason refers to is known as halation.
It might feel strange pushing your primary design goals based on the vision impaired, but when 50% of the population of have this “impairment” it’s actually closer to being the norm than an impairment.
The web is rife with research on the topic, but I think these two quotes provide a succinct justification for why light text on a dark background is a bad idea.
(Tip: If you want to be really good, use an offset grey on a light background like #222 on #fff as it’s a bit nicer on the eyes.)
"Where’s Wally?" Version 2 – Now called "Where’s Nick?"
A group of us at Readify would like to have an open conversation with “Nick”. He’s made some comments here and here that we’d like to open up for some proper discussion.
If you go by the handle of “Nick”, please get in touch with us!
Tech.Ed AU 08: The Ugly, The Bad, The Good
Bugger it. Despite being ridiculously exhausted, I’m going to write this now because I can’t sleep. I’m also doing it in reverse order to finish up on a vaguely positive incline.
The Ugly
I got rightfully slammed in my presentation evals for ARC402. 44% of the audience were Very Dissatisfied. That placed me with the 6th worst scoring session at the conference.
The general trends were:
- I represented a knowledge of the subject (42% very satisfied – a positive here!)
- My presentation skills were satisfactory (47% satisfied – neutral)
- The information presented was bad (42% dissatisfied with usefulness)
- The presentation was ineffective (42% dissatisfied with effectiveness)
Armed with an array of comments to analyse, what did I do wrong? Thinking out loud, this is what I’ve come up with:
- I was put off by the noise from the neighbouring room and the mobile smackdown. I shouldn’t have been affected by this as much as I was.
- I rushed the content, when I was by no means under time pressure. I generally covered this content as a 20 minute segment at the end of a more holistic ASP.NET MVC presentation. While I had added additional content, and that is generally a rushed 20 minutes, I certainly shouldn’t have been rushing here.
- I lost the structure. I didn’t introduce myself (which people highlighted in the comments) and somehow I even forgot to ask for Q+A at the end, even though there’s a whole slide that prompts me to do just that.
- I focused my content too much on the blurb which came from Tech.Ed US instead of thinking myself about the wider architectural considerations. There’s a lot more too it than IoC and some attributes.
- Despite being crowned the Australian Annual IT Demonstration Champion this same week, my demo crashed and burned. Massive fail here.
- I’m still not good at dealing with non-developer audiences. This was something that also affected me at Web on the Piste, and is something I need to actively work on. As much as I am a fan of minimal slides + heaps of live code, if the people ask for high level content in an architecture track, it’s what you’ve got to give them.
Summarising:
I failed to identify the key differences between the demands of this session and those demands of previous talks I had done in this technology space. I was over confident in the content and thus failed to properly prepare and update my content for the latest release, the audience and the timing. I’d like to apologize to those who attended and expected more, the content owners who trusted me to be there and the community who supported me in getting there in the first place.
- Tatham Oddie, not-so-demo-champion
The Bad
I’m forever fighting with a balance between helping and helping too much. I was a key person on the Dev.Garten project this year, having done a significant amount of work pre-event including meeting with the client and developing infrastructure. Once the event actually started I began to realise the shear number of things I’d committed to doing throughout the week and that I was being stretched. While there were plenty of great people to keep the project moving, I could have done a better job of documenting the directions I had started and ensuring a smoother handover.
The Good
Despite this post starting on a decidedly (and deservedly) sour note, there were some amazing this that happened during the week.
My other session (TOT352) about Software+Services had a particularly small audience, however came out with 100% of the evals saying the demos were effective and 100% saying the technical content was just right. Ok, so the data is only working off 2 evaluations because there were only about 12 people in the room, but it’s better results than above either way.
I won the national final of the Demos Happen Here comp. Among other things, this means I’m off to Tech.Ed Los Angeles in 2009 and will shortly receive a shiny new Media Centre PC. When I made the original entry video it was an 8 minute demo, however by the national final I had it down to 4 mins 50 seconds which is a real testament to the quality of Windows Server 2008.
I built a Surface application. Amnesia own the only two Surface devices currently outside of the US and were kind enough to let me spend a day and a half playing on it before they took one to the event. It was my first time ever compiling a line of WPF or seeing the Surface SDK but in that 1.5 days I managed to get an application working which would pull session data out of CommNet and display it in response to a conference pass being placed on the table. The Surface team should be really proud of the quality of SDK that they have achieved to make that possible and I look forward to when we finally get to see a widespread public release of the bits.
The table achieved quite a bit of interest throughout the week:
On Wednesday I had lunch with Amit Mital who is the GM of Windows Live Mesh. Six of us (him, 2x MS, 2x others, me) spent a good 90 minutes discussing some of the longer term visions for Mesh. The original plan was for us to ask questions and him to answer them, but it became more of a discussion between ourselves about scenarios we wanted to see / achieve and him (relatively) quietly taking notes. In the end this was a better approach because it allowed him to walk away with some real world scenarios and didn’t result in us constantly asking him questions he wasn’t allowed to answer yet. PDC sounds set to deliver some exciting changes as we see the release of the Mesh SDK.
Friday lunchtime I was invited to present with Lawrence Crumpton about open source at Microsoft. We were presenting to a lunch of open source alliance and higher education administrators trying to demonstrate that Microsoft aren’t actually evil. Lawrence’s full time job at Microsoft Australia lies around open source and it was amazing to hear some of the things he’s involved in. I jumped on stage after his talk to demonstrate PHP on IIS7 as a first class citizen and talked about leveraging the platform with functionality like NLB. (This may or may not sound very similar to my DHH demo.)
Tech.Ed week is also a big week for Readify because it’s the only time we get to have almost all of our people in the one place. It’s a strange feeling knowing a whole group of people but then meeting them for the “first” time. It was particularly good meeting our new WA gang (Hadley Willan, Jeremy Thake and Graeme Foster) as well as catching up with the out of towners and management teams again.
Friday night was the Readify Kick-off party followed by a company conference / meeting on Saturday.
Who’d have thought I’d get to see my Principal Consultant gyrating his hips on stage with Kylie? I’ve had a quick look around Flickr and Facebook but I haven’t found any photos of the night online yet. I look forward to our resident photographers catching up on their uploads early this week. Update: Links at end of post.
Rog42 came along as a guest speaker on Saturday and delivered a great presentation about some new approaches for community. In a demonstration of how a little information goes a long way, the pizza thing is now pretty superfluous having seen his presentation but I think we can keep the jokes going for a little bit yet. 
It was encouraging to see the level of Readify involvement in Tech.Ed.
Overall it was a great week and another well executed Tech.Ed on Microsoft’s behalf. I was privileged to be invited to participate in lots of different ways, albeit with different qualities of outcome. It’s been an eye opening week which has highlighted needed work on my behalf, but also being rewarding for work I’ve already done. I look forward to the next event, and all of the other things that will need to be tackled between now and then.
Update 7-Sep-08: Photos from Thursday night courtesy of Catherine Eibner:
Update 8-Sep-08:
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Added blurb about open source talk.
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Added link to Kylie video.
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Added link to Readify Tech.Ed involvement video.
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Readify kickoff dinner photos appearing here: http://flickr.com/photos/jakkaj/sets/72157607167191084/
Guerilla Tech.Ed Marketing?
I can hear the spray cans further up the stair well. It seems the DPE guys are going guerilla in the Microsoft stairwells…
Solution: IIS7 WebDAV Module Tweaks
I blogged this morning about how I think WebDAV deserves to see some more love.
I found it somewhat surprising that doing a search for iis7 webdav “invalid parameter” only surfaces 6 results, of which none are relevant. I found this particularly surprising considering “invalid parameter” is the generic message you get for most failures in the Windows WebDAV client.
I was searching for this last night after one of my subfolders stopped being returned over WebDAV, but was still browsable over HTTP. After a quick visit to Fiddler, it turned out that someone had created a file on the server with an ampersand in the name and the IIS7 WebDAV module wasn’t encoding this character properly.
It turns out that this issue, along with some other edge cases, has already been fixed. If you’re using the IIS7 WebDAV module, make sure to grab the update:
Update for WebDAV Extension for IIS 7.0 (KB955137) (x86)
Update for WebDAV Extension for IIS 7.0 (KB955137) (x64)
Because the WebDAV module is not a shipping part of Windows, you won’t get this update through Windows Update. I hope they’ll be able to start publishing auto-updates for components like this soon.
Shout Out: WebDAV – a protocol that deserves more love.
I’m a massive fan of WebDAV.
At Fuel Advance (the parent company behind projects like Tixi), we operate a small but highly mobile work force. We don’t have an office, and we need 24/7 access to our business systems from any Internet connection. VPN links are not an option for us – they suck over 3G and don’t work through most public networks.
Enter WebDAV. It’s a set of HTTP verbs which give you read/write access to a remote folder and its files, all over standard HTTP. The best part is that Windows has native support for connecting to these shares. Now, we all have drive letter access to our corporate data over the public Internet. It’s slim and fast without all the management overheads that something like Sharepoint would have dealt us. It’s also cross platform, allowing us to open the same fileshares from our machines running Mac OS X.
IIS6 had reasonable support for WebDAV, but for various (and good!) reasons, this was dropped from the version that shipped as IIS7. In March this year, the team published a brand new WebDAV module as a separate download. This module is built using the new integrated pipeline in IIS7 and is much more nicely integrated into the management tool.
Kudos to Keith Moore, Robert McMurray and Marchel Cohn (no blog) for delivering this high quality release!
Video: The best web stack in the world
This is the demo I made for the Microsoft Demos Happen Here competition. The criteria was that it had to be under 10 minutes, and show one or more of the features from the launch wave technologies – Visual Studio 2008, SQL Server 2008 and Windows Server 2008.
I chose to demonstrate PHP running on IIS7 using FastCGI, then integrating this with an ASP.NET application before finally load balancing the whole application between two servers in a high availability, automatic failover cluster.
I managed to do all that with 2 minutes to spare, so I think it’s pretty clear that Windows Server 2008 is the best web stack in the world.
Update 5-Sep-08: I won. 
Tearing down the tents (and moving them closer together)
Being fairly focused on Microsoft technologies myself, I see a lot of the “us vs. them” mentality where you either use Microsoft technologies, or you’re part of “the other group”. Seeing Lachlan Hardy at Microsoft Remix was awesome – he was a Java dude talking about web standards at a Microsoft event. The more we can focus on the ideas rather than which camp you’re from, the more we’ll develop the inter-camp relationships and eventually destroy this segmentation. Sure, we’ll still group up and debate the superfluous crap like which language is better (we’re nerds – we’ll always do that) but at least these will be debates between the sub-camps of one big happy web family. (It’s not as cheesy as it sounds – I hope.)
What’s the first step in making this happen? Meet people from “the other group”!
The boys and girls at Gruden and Straker Interactive have put together Web on the Piste for the second year running. It’s a vendor neutral conference about rich internet technologies – so you’ll see presentations about Adobe Flex and Microsoft Silverlight at the same event (among lots of other cool technologies of course). These types of events are a perfect way to meet some really interesting people and cross pollinate some sweet ideas.
It’s coming up at the end of August, and I understand that both conference tickets and accommodation are getting tight so I’d encourage you to get in soon if you’re interested (Queenstown is crazy at this time of year).
And of course, yours truly will be there evangelising the delights of Windows Live as well as ASP.NET AJAX to our Flash using, “fush and chups” eating friends.
Will you be there?
Gotcha: Microsoft WebDAV Extension for IIS 7.0
Are you getting this error trying to install the WebDAV extensions on your Windows Server 2008 box?
The IIS 7.0 CoreWebEngine and W3SVC features must be installed to use this product.
It could mean that you tried to install the wrong architecture (x86 vs. x64). Noob.
(Of course, I haven’t just spent the last 5 minutes working that out.)
