Scrum and agile says that items on the current sprint backlog should be approached in priority order, and one item at a time by the whole team.
Practically, that never seems to work for our team. Either the item is too small for all team members to be productive (including taking pairing into account). So we end up perhaps doing two or three items across the team at any one time.
I'd be interested to hear how other teams do it, and also how many items they usually commit to in a given sprint.
items on the current sprint backlog should be approached in priority order, and one item at a time by the whole team.
I don't know who says this, I at least don't remember having heard or read anything like the emphasized text so far. Of course, it depends also on whether an item for you is a story or a single task.
If it's a story (usually consisting of several tasks), there might be a chance of achieving this. However, as you say, sometimes the story just doesn't include enough tasks to keep everyone busy. Also often the tasks related to a story strongly depend on each other, e.g. there might be a design session (involving part or whole of team), then one or more coding tasks, then code review, functional testing, documentation etc. Obviously one can't do functional testing before the coding, and so on.
Since everyone has to do something, there will be at least as many tasks open at any given time as there are team members (or pairs). Taking into account that sometimes tasks are on hold for various reasons (inter-task dependencies, information needed from external parties etc.), usually even more.
In one Scrum project with a team of 4 developers, we had a very similar situation. We did strive to take stories in priority order as much as possible, and usually we had multiple stories and several tasks open at any time. In the beginning we often had problems with several half-finished stories at the end of the sprint. So we realized it is important to keep the number of open tasks / stories to a minimum, i.e. always attempt to finish open tasks /stories first before starting a new one. But practically, that minimum was never meant to be 1.
As for the number of stories per sprint, we just put in as many as we could comfortably fit in based on our (story, then task level) estimations. That was of course greatly influenced by our velocity, which in the beginning was estimated too high. After a couple of months we chipped it down to 60%, and that value seemed to work for us.
I think it depends on the makeup of your team. If you have a team where anyone can take on any given task within a user story, then this works well. If you do not, then there will likely be idle time for some individuals.
The point in working the user stories based on priority is simple... you get the highest priority user story completed first. This adds the most value from the perspective of the customer who actually set the priority.
As for how many user stories to commit to during a sprint, that depends on a few factors: Team Availability, Team Velocity, and Sprint Duration. So, I'm not sure how much value you will get out of knowing how many stories other people tackle during a sprint.
The advice to approach each item by the whole team is there to avoid creating mini-waterfalls within sprints, where items are passed from one specialized group to another. That leads to stuff like testers having nothing to do in first days of the sprint, then working overtime for the last couple of days when coders fiddle their thumbs. Teams should approach the problem as a whole with everyone chipping in, even outside of their respective "specialization". Yes, coders can test, testers can code and both can design architectures etc. - and in the process learn something new (amazing). That is not to say everyone should be very good at everything - it is just to say attitude like "I don't test, I'm a coder" or "I won't write this script, I'm a tester" should have no place in a Scrum team.
It is also advised to tackle items one by one inside of sprint to make sure something is actually delivered at the end. Limiting work in progress (WIP) prevents situation, where everyone did some tasks on each item, but no item has been completed by sprint's end.
However, this shouldn't be viewed as advice, not a very strict rule. For example when you have two small stories and a team of 10 it probably doesn't make sense to have all of the team swarm on just one story.
Bottom line is: no one should tell the team how to divide work among themselves, but delivering what they committed to at Sprint Planning should be expected.
Noel, is your team trained to work in a Scrum team ? I mean did you send them to Scrum Course prior beginning the project ?
I've seen so many team failing with Scrum just because they misunderstood what was written in a book on a blog.
Also having an experienced Scrum Practitioner or Scrum Coach will help you a lot.
To answer your question specifically, check this nice free ebook that is different than others:
http://www.crisp.se/henrik.kniberg/ScrumAndXpFromTheTrenches.pdf