You are left with a bunch of ideas from your ideation brainstorm, and want to select the most promising for further pursue.
The method is about selecting the best ideas. It is important to get a lot of ideas, but it is also crucial to prioritize them. Do that by holding the ideas up against some of the parameters you use to measure the success of the progress on. A parameter can be "realizability" which is about whether the idea can be realized within the existing organizational framework.
The method is performed in groups.
Print the Priority Grid.
Write the selected parameters on each axis and degrees of difficulty and ease. Parameters can be, for example "value to the user" or "integrity".
Discuss each idea in the group concerning the parameters and place them according to the Priority Grid. Once all ideas are placed, the prioritization begin.
The prioritization can take place as follows: Ideas located in the lower left corner (hard to achieve with a minimum value for the user) can be taken directly off the board. The ideas in the lower right corner (highly realizable but low value for the user) must either be rejected or modified. For the ideas in the upper left corner (hard to realize, but of high value to the user) you can be "plant a seed" and maybe work on them later. The ideas that are in the upper right corner (easily achievable with high value for the user). These will be the ideas that are best to work with.
Now you have identified the potential of the ideas in relation to your criteria, and you can then make an informed selection of your ideas.