I'm in an agile team, with some developers, a designer and a ux guy. Sometimes we split some user stories into tasks when we think they are too big.
When doing this, I've always read that we should split user stories into small features (so we can have a potentially shippable product after each task). However most of my team members insist in splitting tasks into work type (e.g. a task for wireframes for this user story, then another for design, and another for implementation). I understand that is a bad way, since we're not getting potentially shippable products, but I can't seem to make it clear for them that we need to change this. How could I do this?