招募SDET來當QA是必要的嗎? 正確的嗎?
我想這篇真的很值得大家看一下.
尤其是你在掙扎, 是否要效倣Microsoft hire大量的SDET來做QA的工作時, 這裡提出了不同的見解, 提出了這樣的作法的盲點在哪裡.
此外在後面, 作者和James Bach所提到QA和RD想法上的差別, 我想是非常一針見血的見解. Enjoy it
What's an SDET - II
http://xndev.blogspot.com/2009/03/whats-sdet-ii.html
March 06, 2009
Posted by Matthew
Published in Creative Chaos
我想很多人都看過"The art of software testing", 在書中最有名的例子, 是測試一個三角形的程式. 讓我先回顧一下這個題目
有一個程式, 會讀入三角形的三邊長, 然後會輸出這個三角形是何種三角形. 比如說, 正三角形, 等腰三角形, 一個普通的三角形, 和不是三角形等等.
作者認為, 書中的回答是非常RD style的答案, 為什麼呢? 作者解釋如下:
作者認為如果你只是注意input 和expected results, 那你心中只看到這樣的東西
my $triangle_type = get_triangle_type($sidea, $sideb, $sidec);
然後你會做以下的測試
- The basic equivalence classes,
- The boundaries,
- Maybe measure statement coverage - maybe even branch coverage,
- Perhaps have a bunch of negative tests like entering words instead of numbers,
- A "length" of a negative number
- In the days of MS-DOS where you had a single user sitting at a single computer typing in one value at a time, that might be just fine.
但是作者認為, 在現在的環境中, 只做對了一半. 因為通常我們的程式, 會放在web上執行, 或是做成 web service讓別人呼叫. 因此你可能還需要考慮以下問題
- Does it render correctly in all browsers? IE6, IE7, FF2, FF3, Safari?
- Does it look pretty? Is the user interface usable?
- What happens if I resize the browser? Does the new rendering make sense?
- If I click tab through the various inputs instead of using the mouse, does the change in order make sense?
- If I press the "ENTER" or "RETURN" key, does that trigger the submit button?
- What happens if I click "submit" twice in a row - really fast?
- What happens if, after I click submit, I click the back button? Do I go back to the main screen or do I get one of those bizarre "This page was generated dynamically do you want to re-post?" error messages?
- What if I am visually impaired? Can I turn up the font or does the Cascading Style Sheet "lock" down the user experience? If I can crank up the font is it visually appealing?
- What if I am blind? Can I use the application by a tool for the blind like Lynx? Do all of the images have "alt=" tags?
- Is the web service reasonably fast? What if it's used by 100 users all at the same time? (Note: This was never a problem on MS-DOS, where you only had one user at a time)
- Can I run the application on my 1024x600 netbook? The ads said my netbook was good "for web surfing"
- Can I run the application on my Cell Phone?
- If I come in from a chinese, korean, or italian system but I know english, does the user experience make sense?
- What if I don't know English? Should our software be localized? If yes, what localizations?
這就是會什麼作者覺得書上的答案是不夠的, 這個三角形的例子是不夠理想的, 因為它只著重在某一類型的測試, 而忽略了其他類型的測試.
所以作者認為如果你只是hire RD來當 QA, 其實是一件很危險的事. 因為他很可能都只是注意到前半部的測試 : code, code, and statement coverage, 而不會去想到後半部的測試.
作者還認為, 我們在前半部份的測試,通常都做的很好. 但是對於後半部的測試, 我們經常是缺乏根據使用者的經驗, 來建立一些在real world會遇到的測試
以下是作者認為Microsoft對QA的態度
===============================================
Now, the Microsoft Guys claim to be doing it right.
They want Software Design Engineers in Test (SDETs) who can do *both* entry-level developing *and* critical investigation of software under test - and there are some people who fit into that category.
But that's like saying you want excellent sprinters who are also world-class distance runners - while they do exist, there just ain't that many of those people on the planet.
Those that are here can usually find gainful employment, and not all of them want to live in Washington State, China or India.
The result is that, as an employer, you'll either have to (A) Pay an relative large sum for these people, (B) Have a bunch of open positions while you look for people with the right mix, or (C) Compromise, hiring people who are, for example, good devs you think might make good testers.
This runs the serious risk of developer myopia.
===============================================
之後作者和他同事James Bach (有名的software testing作者)討論過, 以下是Jame Bach的意見
The words that you quoted [Matt talking about MS's view of testers] represent an attitude that systematically misunderstands testing as a purely (or primarily) a technical activity the object which is to produce "test cases." I too had that attitude, early in my career.
I grew out of it as I came to understand, through my experiences as a test manager, that a test team becomes stronger when it hosts a variety of people with a variety of backgrounds.
Through the ordinary action of teamwork, a diverse group of thinkers/learners exploits the knowledge and skills of each for the benefit of all.
My attitude about testing is deeply informed by a study of cognitive psychology, which is the study of how people think, and epistemology, which is the study of how people can know what they know. ...
When you approach testing not as hot-dogging with test tools or techniques, but rather as a process of human minds encountering human artifacts and evaluating them in human terms for other humans, you eventually realize that the testing process is harmed when any one point of view or way of thinking comes to dominate it.
I would like at least one programmer on my test team. Maybe a few.
In some cases (such as in testing development tools) I will need everyone to be a programmer.
However, I do not treat programming ability as the center of gravity for testing.
Instead I look for rapid learning, high tolerance for uncertainty, and general systems reasoning.
Even then, I don't need EVERYONE to be good at those things.
=======================================================
之後是作者的想法:
I'd use different rhetoric and be less critical, but I understand what James is saying.
As testers, we tend to have developer-envy.
The reality is that the two skills are separate, distinct, and complementary.
(Unless, say, you are testing a compiler or a debugger. Are you?)
Now, can a non-developer-tester be a more effective by picking up a little code?
Absolutely. I have an undergraduate degree in Math/CS and a Master's in CIS, of which I am extremely proud - not to mention a decade with a title of developer on my business card.
AND it took me years to fight my way through developer myopia to see the whole picture of software testing.
Developers tend to think in terms of automatable business processes - when exactly what needs to be done up front isn't clear, developers claim that the requirements are "inconsistent" and refuse to program.
The whole picture of testing might include some repeatable elements, but it also includes empirical processes - which adapt through learning as they happen.
This is not a straightforward business process to automate. Developer-Envy doesn't help our craft, it hurts it.
我想這篇真的很值得大家看一下.
尤其是你在掙扎, 是否要效倣Microsoft hire大量的SDET來做QA的工作時, 這裡提出了不同的見解, 提出了這樣的作法的盲點在哪裡.
此外在後面, 作者和James Bach所提到QA和RD想法上的差別, 我想是非常一針見血的見解. Enjoy it
What's an SDET - II
http://xndev.blogspot.com/2009/03/whats-sdet-ii.html
March 06, 2009
Posted by Matthew
Published in Creative Chaos
我想很多人都看過"The art of software testing", 在書中最有名的例子, 是測試一個三角形的程式. 讓我先回顧一下這個題目
有一個程式, 會讀入三角形的三邊長, 然後會輸出這個三角形是何種三角形. 比如說, 正三角形, 等腰三角形, 一個普通的三角形, 和不是三角形等等.
作者認為, 書中的回答是非常RD style的答案, 為什麼呢? 作者解釋如下:
作者認為如果你只是注意input 和expected results, 那你心中只看到這樣的東西
my $triangle_type = get_triangle_type($sidea, $sideb, $sidec);
然後你會做以下的測試
- The basic equivalence classes,
- The boundaries,
- Maybe measure statement coverage - maybe even branch coverage,
- Perhaps have a bunch of negative tests like entering words instead of numbers,
- A "length" of a negative number
- In the days of MS-DOS where you had a single user sitting at a single computer typing in one value at a time, that might be just fine.
但是作者認為, 在現在的環境中, 只做對了一半. 因為通常我們的程式, 會放在web上執行, 或是做成 web service讓別人呼叫. 因此你可能還需要考慮以下問題
- Does it render correctly in all browsers? IE6, IE7, FF2, FF3, Safari?
- Does it look pretty? Is the user interface usable?
- What happens if I resize the browser? Does the new rendering make sense?
- If I click tab through the various inputs instead of using the mouse, does the change in order make sense?
- If I press the "ENTER" or "RETURN" key, does that trigger the submit button?
- What happens if I click "submit" twice in a row - really fast?
- What happens if, after I click submit, I click the back button? Do I go back to the main screen or do I get one of those bizarre "This page was generated dynamically do you want to re-post?" error messages?
- What if I am visually impaired? Can I turn up the font or does the Cascading Style Sheet "lock" down the user experience? If I can crank up the font is it visually appealing?
- What if I am blind? Can I use the application by a tool for the blind like Lynx? Do all of the images have "alt=" tags?
- Is the web service reasonably fast? What if it's used by 100 users all at the same time? (Note: This was never a problem on MS-DOS, where you only had one user at a time)
- Can I run the application on my 1024x600 netbook? The ads said my netbook was good "for web surfing"
- Can I run the application on my Cell Phone?
- If I come in from a chinese, korean, or italian system but I know english, does the user experience make sense?
- What if I don't know English? Should our software be localized? If yes, what localizations?
這就是會什麼作者覺得書上的答案是不夠的, 這個三角形的例子是不夠理想的, 因為它只著重在某一類型的測試, 而忽略了其他類型的測試.
所以作者認為如果你只是hire RD來當 QA, 其實是一件很危險的事. 因為他很可能都只是注意到前半部的測試 : code, code, and statement coverage, 而不會去想到後半部的測試.
作者還認為, 我們在前半部份的測試,通常都做的很好. 但是對於後半部的測試, 我們經常是缺乏根據使用者的經驗, 來建立一些在real world會遇到的測試
以下是作者認為Microsoft對QA的態度
===============================================
Now, the Microsoft Guys claim to be doing it right.
They want Software Design Engineers in Test (SDETs) who can do *both* entry-level developing *and* critical investigation of software under test - and there are some people who fit into that category.
But that's like saying you want excellent sprinters who are also world-class distance runners - while they do exist, there just ain't that many of those people on the planet.
Those that are here can usually find gainful employment, and not all of them want to live in Washington State, China or India.
The result is that, as an employer, you'll either have to (A) Pay an relative large sum for these people, (B) Have a bunch of open positions while you look for people with the right mix, or (C) Compromise, hiring people who are, for example, good devs you think might make good testers.
This runs the serious risk of developer myopia.
===============================================
之後作者和他同事James Bach (有名的software testing作者)討論過, 以下是Jame Bach的意見
The words that you quoted [Matt talking about MS's view of testers] represent an attitude that systematically misunderstands testing as a purely (or primarily) a technical activity the object which is to produce "test cases." I too had that attitude, early in my career.
I grew out of it as I came to understand, through my experiences as a test manager, that a test team becomes stronger when it hosts a variety of people with a variety of backgrounds.
Through the ordinary action of teamwork, a diverse group of thinkers/learners exploits the knowledge and skills of each for the benefit of all.
My attitude about testing is deeply informed by a study of cognitive psychology, which is the study of how people think, and epistemology, which is the study of how people can know what they know. ...
When you approach testing not as hot-dogging with test tools or techniques, but rather as a process of human minds encountering human artifacts and evaluating them in human terms for other humans, you eventually realize that the testing process is harmed when any one point of view or way of thinking comes to dominate it.
I would like at least one programmer on my test team. Maybe a few.
In some cases (such as in testing development tools) I will need everyone to be a programmer.
However, I do not treat programming ability as the center of gravity for testing.
Instead I look for rapid learning, high tolerance for uncertainty, and general systems reasoning.
Even then, I don't need EVERYONE to be good at those things.
=======================================================
之後是作者的想法:
I'd use different rhetoric and be less critical, but I understand what James is saying.
As testers, we tend to have developer-envy.
The reality is that the two skills are separate, distinct, and complementary.
(Unless, say, you are testing a compiler or a debugger. Are you?)
Now, can a non-developer-tester be a more effective by picking up a little code?
Absolutely. I have an undergraduate degree in Math/CS and a Master's in CIS, of which I am extremely proud - not to mention a decade with a title of developer on my business card.
AND it took me years to fight my way through developer myopia to see the whole picture of software testing.
Developers tend to think in terms of automatable business processes - when exactly what needs to be done up front isn't clear, developers claim that the requirements are "inconsistent" and refuse to program.
The whole picture of testing might include some repeatable elements, but it also includes empirical processes - which adapt through learning as they happen.
This is not a straightforward business process to automate. Developer-Envy doesn't help our craft, it hurts it.
