The Persona-Scenario Matrix (PSM) is a chart that indicates which personas occur in which usage scenarios.

In real life, many different (types of) users may interact simultaneously with a product or intervention. Designing an intervention one user at a time ignores the interactions between multiple users. Those ignored interactions can cause problems and failures, harm to users, and loss of effectiveness and efficiency. Conversely, an ignored interaction can also be a missed opportunity to create a new type of functionality that would serendipitously improve the users' experience.

Key to capturing those interactions between different types of users is to actually recognize which types of users are likely to interact together with your design intervention. The Persona-Scenario Matrix serves the purpose of helping you create scenarios with all the “right user groups” represented.

• TODO Domain of problems that succumb.
• TODO Describe unbalanced forces that can be addressed.
• TODO Inputs: what's needed to generate concept / execute method.
• TODO Examples of typical situations.

You need to have already identified a collection of personas for various user groups. If you haven't done that yet, go do that now.

Create a table or chart. List each persona's name on a separate row. Each scenario will get a column in the table.

Think of a typical circumstance under which your design intervention will be used. Which of the personas will take part in that scenario? For each scenario, check off the table cells corresponding to the personas that will take part in it.

Once you've accounted for all the scenarios you think you need, look at the PSM as a whole.

• Does the PSM reflect the actual usage scenarios you have written out?
• Are all the personas in at least one scenario?
• For any given scenario, are all the likely participant personas present?

As you discover problems in the PSM, you may have to go back and revise your personas, or perhaps add new ones. Similarly, you may need to adjust your scenarios or create additional ones to account for likely circumstances you have forgotten about.

A basic PSM might look like this:

Each row represents a different persona, and shows the scenarios in which they participate and interact in that scenario, as either a user or a co-user. Here are some general examples for the three scenarios in the PSM above:

Carpooling to work

Includes three different personas representing the driver and two passengers.

The grandkids come over

Includes personas for various kinds of children, of grandparents, and of the parents, as well as possible other people (e.g., pizza delivery people, neighbours complaining about noise, etc.)

Study cubicle at library

Might include personas for students, library staff, other users of other library facilities, thieves, custodial staff, professors, etc.

For any of these scenarios, changing even one persona can change almost everything about how you model the scenario generally, so you have to think through which personas are most likely to interact, and in which situations those interactions will occur.

You have been tasked with designing a way to sharpen pencils for elementary school classroom use. Having conducted appropriate background work, you have found the following key issues pertain:

• There have been cases of small fires when liquids were spilled on electric sharpeners.
• There have been cases of children hurting themselves by sticking their fingers into electric sharpeners.
• Lineups of children waiting to use the sharpener lead to classroom disruptions.
• Some children don't know when to stop sharpening their pencils.
• Existing sharpeners are difficult to maintain; they tend to clog with filings.
• While being emptied, the sharpeners pose an increased safety risk to children.
• While being emptied, children will often “accidentally” spill the filings, which cause further disruptions.

Some obvious personas might include the following. (Please note that these personas are highly abbreviated; actual personas would be much more detailed.)

• Sally, a “typical” female student.
• Ahmed, a young Canadian-born Muslim male.
• Mirela, a female student with poor eyesight.
• Bob, a male student with moderate ADHD.
• Gary, an able-bodied, early-career teacher.
• Anne, a female teacher in her 50's, and has limited mobility in her lower back.
• Stan, the male janitor who cleans the classroom and also repairs/replaces the sharpeners as needed.

Some reasonable usage scenarios might include the following.

• Day 1: On the first day of class, virtually all the students have new, unsharpened pencils, a circumstance that Gary did not anticipate.
• Will it sharpen?: Bob is very inquisitive, and wants to see if he can make a swordfish (which he saw on TV during science class) by putting the class's goldfish into the pencil sharpener.
• Oops!: Anne puts Mirela is charged of emptying the sharpener before lunch, and Mirela accidentally spills the contents on the floor near the trash bin beside Anne's desk.
• Better get a bucket: Ahmed ate too much candy and vomits on the pencil sharpener.
• Helping out: Anne offers to sharpen Sally's pencil when she came to school in an arm cast, but the pencil sharpener is installed at a height that is too low for her to use.

Here is a PSM for the pencil sharpener situation. Note that u stands for user and c stands for co-user.

Deliverables of this task include:

• a properly constructed and completed PSM, and
• some explanatory text justifying:
  • why each scenario is relevant to the situation of your design, and
  • why, for each scenario, the personas that you listed are relevant.

TODO Describe consequences and counter-indications.