C3 Education

When managing a project you need to gather rough time estimates for tasks, so that you can plan your work. 

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T-shirt sizing is a way to practice relative sizing.  By comparing tasks, you can break them into buckets of small, medium, and large.  You could also include x-small and x-large if needed.  Estimating in relative buckets is more important than estimating absolute time or effort. We want to understand how things compare to each other in a rough sense, and not waste time on false precision.

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Another practice for collecting estimates is called Planning Poker.  Team members individually assign their t-shirt size estimates to a piece of work and show their "cards" at the same time.  This is done to foster collaboration and build consensus.

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1. Label index cards with the names of dog breeds including Chihuahua, Great Dane, Golden Retriever, Poodle, Newfoundland, and Austrian Guildenbaur.

2. On a wall or board, make 3 columns labeled small, medium, and large.
    

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1. Give each student 3 index cards and have them write one size on each card: small, medium, and large.

2. Explain to the class that they will be shown a series of dog breeds.  When a dog breed is shown, they're to raise one of their three index cards based on the size they think is the best fit.  If all students selected the same size, that becomes the estimate. If not, the students discuss their estimates.  After further discussion, each student re-selects an estimate card, and all cards are again revealed at the same time.
   
   The estimation process is repeated until consensus is achieved or until the students decide that a particular item needs to be deferred until additional information can be acquired.
   
   When a consensus is reached the leader will place the dog's index card under the appropriate size heading on the wall. 

3. Assign a student to lead the activity.  This person will facilitate the activity.

4. Begin the activity by showing the Chihuahua card and having the class start the estimation process.  
   
   
    

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1. ​Chihuahua – this is the smallest dog and should be the reference estimate.  The other dog breeds should be sized relative to it.

2. Great Dane – estimates should be large

3. Golden Retriever – estimates should be medium or large

4. Poodle – students should ask for more information (e.g. is it a standard poodle or a toy poodle)?

5. Newfoundland – this is a lesser known dog; those who don’t know what it is should not vote and should instead ask questions

6. Austrian Guildenbaur – this is a trick; the dog breed doesn't exist, so no estimates should be given