zaphCoder

Today I wanted to edit a file on my server. I tend to use Fetch so I fired it up, navigated to my WordPress directory, selected a .php file and clicked on the edit icon. Now I usually use BBEdit so boy was I surprised when it opened in “Ready Lisp”. Wow! I don’t use “Ready Lisp”

I looked through Fetch for an option to set the default editor and could not fine it. I remember that there is sone “funny” non-obvious method to set the editor. Finally I transferred the file to my computer and looked at the Finder Info on the file. Sure enough there is was, Apple had decided that “Ready Lisp” was the default editor for .php files. Huh? OK, in Apple’s infinite wisdom it had set “Ready Lisp” to be the default application for .php files as best as I can figure just because I had installed “Ready Lisp” and tried it once. Bad Apple!

But, just because Apple does something stupid that should not make Fetch do something stupid. Right? Shouldn’t Fetch be able to establish its own file editor associations. It used to be able to but someone at Fetch thought better. Better?

The concept of “Least Surprise” was certainly violated here.

The impetus behind this sort timing test is from the Coursers “algo” course and in particular the Quicksort section. One comment was that sorting was so fast that the cost need not even be considered. It seem that on an iPad (version 3) sort times of short NSString objects in an NSArray are cheap for approximately n < 10,000.

The NSMutablearray contains unique strings of 8 digits in random order. The sort was statement was:
[ma sortUsingSelector:@selector(caseInsensitiveCompare:)];
where ma is the afore mentioned NSMutablearray.

Times were calculated in 1,2,5 step increments from 10 to 500,000 items on an iPad (version 3).

The three lines on the graph are:
Blue: the time in ms so sort the array
Green: n log(n) for a visual slope reference
Yellow: n^2 for a visual slope reference

It can be seen (and numerically verified) that the sort time is very slightly greater than n log(n). This is in agreement with sort times to be expected from the Quicksort algorithm.

The table below contain the sort times as well a n log(n and n^2 for comparison:

items	iPad (3) ms	iPhone 3GS ms	n log(n)	n^2
10	0.104	0.488	1	100
20	0.081	0.161	3	400
50	0.185	0.699	8	2,500
100	0.415	0.814	20	10,000
200	0.948	1.827	46	40,000
500	0.963	5.373	135	250,000
1000	2.963	12.247	300	1,000,000
2000	6.464	27.365	660	4,000,000
5000	14.330	83.051	1,849	25,000,000
10000	41.180	182.578	4,000	100,000,000
20000	196.408	406.931	8,602	400,000,000
50000	565.032	1,140.463	23,495	2,500,000,000
100000	1,244.928	2,487.088	50,000	10,000,000,000
200000	2,703.192	5,396.767	106,021	40,000,000,000
500000	7,476.271	15,125.481	284,949	250,000,000,000

Notice the size of the “Play/Pause” button relative the the “Previous” button (outlined in red). From this it seems obvious that the more important of the two is the “Previous” button. Also notice the close proximity of the two buttons that have very dissimilar actions.

Typically one actually used the “play/pause”button very often and the “Previous” button only on rare occasions. Additionally the “Previous” button does not indicate what it will go back to.

In practice, particularly on an iPad, when one wants to pause the video to consider the content being presented, unless one is very careful one ends canceling out of the current video and being tossed back to the previous video which will start playing. The user will need to pause the video again, carefully not to be sent back even further. When desiring to resume the user will have to click the “Next” button which will cause the desired video to start playing—but at the beginning. Next the user will have to try and find the approximate place where he was when originally attempting to pause the video in-order to resume.

The solution is really simple, separate the two buttons either vertically or horizontally.

The take-away: The UX designer needs to do two things: 1) Actually try a real usage case himself and 2) Have a new user try the UX, without any prompting, and observer. Of course this may require an iteration of the UX.

Perverse as I am, I can’t wait to bring this up in the upcoming “Human-Computer Interaction” course.

Sinage video (2 minutes) as great UX, excerpt from the BBC documentary The Tube This is a great example of well thought-out UX policy that is completely focused on the user with an overall benefit to the users as a whole.

Year	Dates	Announced	Sold-out	Notice
2012	Jun 11 – Jun 15	Wed, Apr 25	Apr 25, 2 hours	47 days
2011	Jun 6 – Jun 10	Mon, Mar 28	Mar 28, 12 hours	70 days
2010	Jun 7 – Jun 11	Wed, Apr 28	May 6, 8 days	40 days
2009	Jun 8 – Jun 12	Thr, Mar 26	Apr 28, 49 days	74 days
2008	Jun 8 – Jun 13	Thr, Mar 13	May 14, 61 days	87 days
2007	Jun 11 – Jun 15	Tue, Feb 06		124 days
2006	Aug 7 – Aug 11	Tue, Mar 07		153 days
2005	Jun 6 – Jun 10	Tue, Feb 15		111 days
2004	Jun 28 – Jly 2	Thr, Feb 26		123 days
2003	Jun 23 – Jun 27	Mon, Feb 10		133 days

Notes:
WWDC 2012: Tickets were announced and became available at 8:30am EDT. At that time Apple updated the site http://developer.apple.com/wwdc and also the Public Relations site http://www.apple.com/pr. The email announcement from Apple arrived at 9:43am EDT. I first learned that the tickets were on sale from am Apple news site http://9to5mac.com close to 8:35am EDT.

WWDC 2011: I purchased my WWDC 2011 ticket at 9:29am EDT. I learned that the tickets were on sale from am Apple news site http://9to5mac.com.

In Black Hat keynote, Whitfield Diffie formulates three rules for making applications secure in the age of the Internet.

Cryptographer Whitfield Diffie reckons one of the most important things for good cryptography and security in the age of the Internet is good code. Unfortunately, really good code is generally too expensive to write.

First, “We need to learn good programming”, he said. The second challenge is fixing human interfaces, so every Internet user can understand what is happening. And third, liability issues should be fixed. “That isn’t easy”, he said, because fixing liability issues should go hand in hand with the technologies that system producers need.

Infoworld

We are so fortunate that Civil Engineers don’t build bridges with the same level of acceptable engineering typically used in software development.

In The Netherlands go to a “BelCompany” store and buy a “vodafone” micro-SIM card: €5, 200MB.

In Belgium go to a “Belgacom” store and buy a “Play&Surf for iPad” proximus MicroSim Card: €10, 200MB.

In England go to a “Three store” and buy an “iPad 3G micro-SIM Ready-t0-Go.”: £9.95, 1GB. Beware that many Internet Cafes have iPhone micro-SIMS but they will not authorize in an iPad.

The first two of the Stanford online courses are now available!

Here are the first two I am taking, I’m still waiting for a couple more.

ALthough the following two courses don’t officially start until March 12, 2012 the first week of lectures, slides, and problem sets are all posted.

These sources are presented under the Coursera umbrella and all current courses can be seen here: About Coursera

Check out the other great current and upcoming titles.

From: The New York TImes, Sunday Review

Anyone who has ever needed noise-canceling headphones in her own office

Headphones are the new office?

People whose work is interrupted make 50 percent more mistakes and take twice as long to finish it.

Is this a good result?

What distinguished programmers at the top-performing companies wasn’t greater experience or better pay. It was how much privacy, personal workspace and freedom from interruption they enjoyed.

This _is_ a good result

Our offices should encourage casual, cafe-style interactions, but allow people to disappear into personalized, private spaces when they want to be alone.