How can I change the weighting of customer data in Preference Interviews?

You can change the weighting of customer data by using the "Market View" feature.

To create a uniquely weighted Market Case, you need a unique Market View. Begin by going to Tool 3.6 within Step 3: 

Create a new Market View:

Let's suppose that Alibaba is by far our biggest customer, representing 50% of the market segment. So, we want to weight their data at 50%. Enter "50" in the "Weight % Override":

Now, just rename this Market View accordingly, and you're finished: