bodmas blog

“One department at software firm Veritas has declared Friday e-mail free, and it found that the day has become its most productive.”

“But author Barry Schwartz told the conference that it was better when we had only a few choices of salad dressing instead of the 175 at his local supermarket.”

Comment: Why not make your own salad dressing? I find a litre of good olive oil lasts well, and decent vinegar is cheap enough. The local Asian shops stock fresh corriander, and garlic and black pepper is always available.

A book called In Praise of Slowness can’t be that bad. A very wise colleague was once enduring a terrible meeting with a ‘seagull’ manager – the manager was saying that we needed to increase efficiency by doing things more quickly. My colleague Nick piped up and pointed out that some things needed to be done more slowly – such as talking to students.

• In Praise of Slowness
• BBC news page about the Technology, Entertainment and Design conference in Oxford

• BBC News page on Sven Jaschan verdict
• Real threat is organised gangs of criminals not ‘stupid teenagers’ according to Sophos chief
• Was Sven Jaschan a ‘script kiddie’?

Marc Rogers specialises in the psychology of computer crime. His ‘new hacker taxonomy’ identifies typical hacker roles – Rogers’ descriptions are based on behaviour as opposed to motivation. A quick summary of the roles follows (direct quotes apart from ‘coders’...

The KeySkills4u Web site aims to motivate keyskills lessons and appears to provide self test quizzes and practice tests in a buzzy and interactive framework.

The best bit is

“These tests are also available on CD to all state-funded post-16 schools and FE colleges in England. For more information please contact the Key Skills Helpline, or tel 0870 872 8081”

I like freebies, and I like a national coordinated approach with consistent content and standards.

• http://www.keyskills4u.com/

The tests are Flash based and are available at Level 1 and Level 2. There is also a mini-test available to decide which level you should be considering.

Six datasets based on reproduction experiments with fruit flies – used for chi-squared statistics calculations…

The Winged flies had well-formed wings that result from double dominant genes or dominant and recessive (both ways round). The Vestigial flies had the stump wings associated with a double recessive gene.

There are worked examples of the calculation and plenty of information on the genetic context available in a laboratory manual designed for US undergraduates published by the University of South Florida. Page 19 has the contextual material and detailed examples.

One student came up with the idea of calculating the chi² statistic based on expected values calculated both for the Mendelian 1:3 ratio and the alternative ratio of 1:2. Many of the data sets result in calculated chi² statistics for both ratios that are less than the critical value of chi² for 5% and 1 degree of freedom, so we can conclude that the sample is too small to distinguish between the two hypotheses.

A motivation for the 1:2 hypothesis could be along the lines that aA and Aa genotypes were regarded as one outcome, so that there were three possible genotypes, AA, Aa and aa. Only the aa leads to vestigial wings, so you get the 1:2 ratio in the offspring. I’m trying to find a historical reference for Aa and aA not being recognised as different equally likely outcomes.

The European Copyright Directive makes it an offence to alter games consoles so as to circumvent games copying controls. ELSPA has successfully prosecuted a case recently in the UK, and this raises issues about ‘change of use’ modification of platforms such as the xbox.

The Entertainment and Leisure Software Publishers Association acts for its members to report copyright infringements to the Police and local trading standards officers. The ELSPA Web site is a very useful resource for teaching / discussing aspects of software piracy in the UK. The Anti-piracy – press office – press releases section of the site has useful short accounts of successful prosecutions of the more blatant infringements. This site is an excellent resource for case studies to highlight the importance of intellectual property and copy- rights generally. I have used case studies to motivate classroom discussions that have often become quite heated.

One recent story that has not made the ELSPA press release page yet was that of a 22 year old Cambridge graduate who is the first person to be prosecuted for selling modified xbox consoles. According to the BBC News report , the modifications consisted of

• adding a large capacity hard drive
• adding additional circuits to bypass copy protection software – so called ‘chipping’
• selling xbox consoles with hard drives loaded with up to 80 games via his own e-commerce Web site

The prosecution was brought under the EU directive that apparently makes the ‘chipping’ of games consoles a specific offence.

I am just wondering which step prompted the prosecution. I hope it was the supply of the hard drive full of pirated games. The xbox console contains a high performance IBM G5 microprocessor. Some years ago, at least one Czech company was selling Playstation 1 consoles adapted to run Linux, with a hard drive, keyboard and facility for connection to a domestic television. The resulting device provided low cost computing access to a number of people.

I hope that similar ‘change of purpose’ modifications to the xbox will not fall under the regulations (outrageous sales of ripped off games should of course).

Imitation is the sincerest form of flattery, and the new Bodmas design is borrowed from Jakob Nielsen’s personal site at http://useit.com/

Nielsen’s site has not had a major redesign since I have been reading it – must be 6 years or so now – and the fact remains that you can find things quickly, make use of the search easily from any page in the site, and the text is readable even if the presentation is austere.

Couple this readability with easy authoring from any Web browser using the WordPress engine and the result has to be an easy way of keeping a home page up to date. I tend to blog things I find when searching for material for students and colleages so each post is short. Being able to add things from any computer in a little corner of time helps keep me writing and adding to this site.

Nielsen’s page is retro in flavour and has a ‘no-nonsense’ look to it, I must admit it does make a change from very small sans-serif text set in white with a wide line spacing on a grey background.