Can you answer this practice T or F question?

Could you perhaps start by explaining why you believe it should be true? Specifically, why would it be 3 and 9? Why would it be a must?

Hi Andy, don't confuse "the optimal Development Team size" with "The Development Team must be..."

The Scrum Guide explicitly states three to nine members are highly recommended, and this is the number you'll see on the exams here.  I agree with the above posts that this is likely a wording problem, not a number problem.

However, in addition to the above posts, the ideal team size has changed over the years.  7 +/-2 (or 5-9) used to be the popular metric, with a number of psychology papers written around it.  I've seen some sources say that anything over 7 members is too big, and 3-7 is perfect.  And even with 3-9 as a reference, this means a Scrum team can scale up to 300% its minimum size.  That's a deceptively large range.

With so many different opinions, you won't always get a consistent answer, particularly on third-party sites.

the dev team should be between 3 and 9, but it MUST not be between 3 and 9.

Tricky because of the phrasing of the question. But this kind of trap is common in every exam.

"Must" is the word to watch in this question.  What helps me is to read the question, re-read the question, re-read the question, pick my answer, re-read the question - AND - have a quick conversation in my head about why my answer make sense or not in consideration of The Scrum Guide.

Exactly what Seth and Olivier said. Can you have a Dev team of only 2 or perhaps 13? Of course! Nothing forbids that. 

Read the Dev Team size section again. You see "Optimal size..." and "Fewer than 3 MAY have problems..." and "larger teams are too complex..." but there is not a single absolute term that determines a rule about the size in that paragraph. 

Change the word "must" to "should" and the answer TRUE would be correct. With "must" in the question, the answer is definitely FALSE.

I feel Curtis's answer is  the best. Thank you all. I was also perplexed by this question. 

This type of question (the wording) IMHO falls into semantics and does not really test knowledge. If it was worded "is required to be" rather than "must" the intent of the question would be much clearer. As is, IMHO it is a badly designed question. 

I also failed in this question. It is a bit unfair a question that falls into semantics instead of knowledge, having into account that Scrum.org does not provide with exams in our own language, only English, this type of "semantic" questions seems provides an advantage to those with English as the first language against the non-English speakers.

To be fair, the question was seen on a third party resource:

There is a practice test by Simon Kneafsey that has the following question. 

The Development Team must be no smaller than 3 or larger than 9 members

I'm not saying it can't happen on scrum.org open assessments or exams themselves, but I certainly didn't have to face semantics/phrasing/poor wording. And I don't recall people complaining of such scrum.org examples - I may be wrong though.

Which brings us to what numerous contributors have pointed out on the forum throughout the years: be cautious when studying and/or practising via online resources unsanctioned by scrum.org, especially if you are discvoering Scrum and you have no or limited experience with it (or with Agile, tbf).

it is a wording issue with word (OR) , it it replaced with (AND) , the answer must be TURE! 

The Development Team must be no smaller than 3 or larger than 9 members

If I break it down

The Dev. Team cannot be 1 or 2 member (no smaller than 3)

The Dev. Team cannot be 10, 11, 12 ( larger than 9 members )

Can't remember the wording in the Guide but lower than 3 = skill constraints    9 or higher = complexity in managing

So True is the answer.

The Scrum Guide does not say "must" it says:

Optimal Development Team size is small enough to remain nimble and large enough to complete significant work within a Sprint. Fewer than three Development Team members decrease interaction and results in smaller productivity gains. Smaller Development Teams may encounter skill constraints during the Sprint, causing the Development Team to be unable to deliver a potentially releasable Increment. Having more than nine members requires too much coordination. Large Development Teams generate too much complexity for an empirical process to be useful. The Product Owner and Scrum Master roles are not included in this count unless they are also executing the work of the Sprint Backlog.

This means you need to do what is correct for your team, but use this guidance as it is proven and know that the bigger you get the more complex...

Ayman and Martin, as Eric mentions, the Scrum Guide provides guidance around optimal team size, but does not mandate team size limits.



There are definitely reasons why you should avoid team sizes smaller than 3 or larger than 9, but it is up to you if you wish to incur the potential risks associated with a less-than-optimal team size.   

it is a wording issue with word (OR) , it it replaced with (AND) , the answer must be TURE! 

Ayman, sorry this is completely incorrect. The wording issue resides on MUST, not OR. The whole 3-9 members is a guideline, not a mandate, therefore it is False to say the team MUST be between 3-9 members.

A Development Team with 2 or 10 members is not guaranteed to fail, while a team with between 3 and 9 members has an increased likelihood of success.

Agility improves the predictability of outcomes. Working to absolute numbers can be less useful than handling probability and range. Examples:

• Sprint capacity
• The amount of work to break down to a day or less in Sprint Planning
• The time to spend on Product Backlog refinement
• The amount of work in a Product Backlog which ought to be “ready” for future Sprints
• Cycle time
• WIP limits
• Throughput
• The size of a Development Team