February 28, 2007

Perhaps They Should Have Tested More - Dow Jones

A bad day for stocks. 
A bad day for Dow's computer systems.

Worldwide stock markets dropped a lot yesterday.  And apparently there were computer problems involved in changing what might have been a slightly more gradual drop into a major, near-instantaneous dropoff.

While some are saying that the level of drop would have been the same without the "glitch", one has to wonder if the panic reaction (and likely resulting sell-off) could have been avoided had the computer systems worked as they should have.

High levels of panic...

"The glitch that caused the near-instant drop of 200 points almost caused a high level of panic, which analysts believe pushed the day price down even further."

Dow Jones could now face a flurry of lawsuits...

"Dow Jones, the company which calculates the US industrial average, was having to defend itself yesterday against accusations that its incompetence exacerbated Tuesday's panic.

Because of the volume of trading, Dow's computers fell behind the market and when they finally caught up, the index appeared to plunge almost 200 points all in one go. The sudden drop intensified panic among already jittery traders.

Dow Jones could now face a flurry of lawsuits from investors who were misled by the computer glitch."

Computer systems just aren't up to scratch when investor panic sets in...

"As sharemarkets plunged around the world, anxious investors, big and small, sat glued to their computer screens. But the lesson learned from yesterday's market correction was that computer systems just aren't up to scratch when investor panic sets in.

The first malfunction came in New York, where a glitch triggered a sudden plunge in the Dow Jones Industrial Average. Brokers, already spooked by morning falls, could do little but watch on as, at 2pm local time, the Dow fell 200 points in seconds.

Dow Jones said its computer system couldn't handle the vast volume of trades — about 4.5 billion, double the daily average — at the New York Stock Exchange.

Dow Jones wouldn't confirm how long its primary system was down (it's rumoured to have been almost hour) but when it switched to a back-up computer system, just before 3pm, the result was a huge drop in the index. The Dow was down at that moment 546 points — its worst single-session decline in more than five years."

A sudden drop in the Dow that called to mind the 1987 crash...

"Prices fell during the morning and early afternoon trading sessions and at mid-afternoon there was a sudden drop in the Dow that called to mind the 1987 crash. At first glance, many market analysts said it looked like it might have been a misprint."

Turning an already bad day in stocks into a head-turning spectacle...

"The NYSE said none of the delays was related to the hybrid system, which combines trades executed by floor brokers with those that are fully automated. The Big Board suspended its electronic platform late Tuesday to bring about an orderly close, and reverted trading to floor brokers.

The messaging system handles messages, not just orders, Pisani said. The entire system saw a surge of traffic--not just orders, but messages spiked dramatically. That spike overwhelmed the system, Pisani said.

The NYSE told Pisani it has "rebalanced" the capacity of the system to handle orders and messages more efficiently.  Officials admitted to him that the system was already supposed to be able to handle the traffic that was generated.

Meanwhile, a computer glitch triggered a sudden plunge in the Dow Jones Industrial Average at mid-afternoon Tuesday, turning an already bad day in stocks into a head-turning spectacle.

Dow Jones, the media company that manages the well-known index of 30 blue chip stocks, said it discovered shortly before 2 p.m. that its computers weren't properly handling the day's huge volume in trades at the New York Stock Exchange.

It switched to a backup computer, and the result was a massive swoon in the index as the secondary system took over processing shortly before 3 pm.

The Dow plunged about 200 points almost instantly, and was down as much as 546 points -- its worst single-session decline in more than five years, and one that sent the blue chips into negative territory for the year."

Intensified panic among many already jittery traders...

"Dow Jones faced a flurry of lawsuits last night after the business information provider admitted that a computer glitch had misled investors about the value of its benchmark stock index and potentially exacerbated some institutions’ losses by millions of dollars.

The company, which publishes The Wall Street Journal, acknowledged that it miscalculated the Dow Jones industrial average index for 70 minutes on Tuesday. It added confusion to a market already reeling, helping US stocks to their biggest fall in four years. At 1.50pm in New York the Dow Jones computer system became overwhelmed by the heavy share trading triggered by plunging stock markets in China and growing economic uncertainty in America.

The data backlog meant that for the following 70 minutes the 400 “live” Dow Jones indices fell by less than they should have done before plunging disproportionately at 3pm, when the backup system was activated and the backlog was cleared.

The apparent 178-point plunge in the Dow Jones in less than a minute – as the index caught up – implied that US stocks were in far worse health than was the case and intensified panic among many already jittery traders.

Lawyers will say that many costly investment decisions were made during the 70 minutes when the Dow Jones was miscalculated in the aftermath of the plunge that occurred after the system caught up. Many derivative and index-linked mutual fund investments that are based on Dow Jones’s own index calculations – as opposed to those conducted separately, based on individual stock prices – will have suffered investment losses from the computer glitch, lawyers will argue."

In just three minutes the Dow fell by more than 240 points...

"When Dow Jones figured out what was happening — they weren't getting the values of the underlying component stocks in a timely manner — they switched to a backup system that was getting it right. That happened at 2:57 p.m. The rest is history.

In just three minutes the Dow fell by more than 240 points.

Jaws dropped on the floor of the New York Stock Exchange and in newsrooms around the country. What was happening? A market crash?

The answers weren't clear, but traders did what they do best: react, and fast.

They started placing sell orders, trying to get out in front of a stock plunge no one really understood.

They wanted to keep their precious ones and zeros, and to do that they needed to turn them from electronic shares of stock into electronic dollars right away.

Billions of dollars in stock value vanished over the cliff...

"This switch-over caused prices that were received during the latency period to be processed all at once, bringing the index immediately in line with its underlying component stocks," says a press release issued by Dow Jones.

The almost instantaneous drop — a compression of all the selling that had happened in the previous 70 minutes — triggered even more selling.

It was a snowball effect, where billions of dollars in stock value vanished over the cliff in the last hour of the trading day."

A massive swoon in the index that happened in the seconds it took Dow Jones to switch to its secondary computers...

"When the Dow Jones industrial average plunged to its low of the session Tuesday, it happened with incredible swiftness -- a matter of seconds -- because of a computer glitch that kept some trades from being immediately reflected in the index of 30 blue chip stocks.

Dow Jones & Co., the media company which manages the flagship index, said around 2 p.m -- just two hours before the New York Stock Exchange was to close -- it was discovered computers were not properly calculating trades. The company blamed the problem on the record volume at the NYSE, and switched to a backup computer.

The result was a massive swoon in the index that happened in the seconds it took Dow Jones to switch to its secondary computers"


February 17, 2007

QA and Testing Interview Questions (And Some Answers)

When interviewing for a QA or Testing position, it's important to be honest.

Hiring managers want to know what you know, what you can do, and what you are like.  And nobody wants to hire a liar. copyrightjoestrazzere

As a hiring manager, I can tell if you are stretching the truth - particularly if you are just repeating simple definitions to complex concepts.

If you are asked about QA or Testing terms that aren't familar to you, tell the interviewer that you haven't heard of those terms, then ask what they mean.  Since terms in this field are very company-specific, you may already know the concept, but just haven't heard the term before.

If you are asked about a tool that you haven't used before, tell the interviewer that you haven't used it.  Sometimes, you can point out other, similar tools that you have used.  Usually, if you are capable of learning one tool, you are capable of learning many.  And if you are good enough otherwise, many companies will hire you and train you on their tool of choice.

That said, some people posting at SQAForums.com (where I help moderate) constantly ask about interview questions.  We now have an Interview Questions forum there, which can help answer your questions.

Here are some other links which may help those who find value in such things.  I will not vouch for the accuracy of any of the answers, nor that any of the questions make sense.

But if you asked for help with interview questions, I sincerely hope this gives you what you are seeking.  Good luck on your interview!

(and if you find a list of questions and answers that actually helped you during an interview, send me an email and I'll note it here)

Questions (and some answers) specifically for QA / Testing
Questions (and some answers) for any interview
Interview questions (and some answers) for Microsoft/Google/etc
Logic Puzzle-style Interview Questions (and some answers)
Other articles related to interviewing

(last updated February 8, 2015)