I want to learn when a user's motivations are high or low while using an app so I can present the right messaging to them and have a higher rate of completion.
Is there a research method which uncovers when a user is motivated to perform a task?
First of all you can't be 100% sure when your users are motivated, but there are several key points-theories that we should mention.
A flow state refers simply when we are really focussed on a task that we are trying to complete (eg. biking, painting, filling a wishlist etc).
So the following tips have to do with our efforts to cause a flow state on our users:
Also have in mind that triggering a flow state may be different for each person, so the previous points are not bulletproof. (Furthermore to have a clearer view, I suggest to view this nice tedx: flow the secret to happiness by Mihaly Csikszentmihalyi, a great researcher on user flows)
Lastly note that while we are trying to set a flow state on a user, if he get distracted from anything, he will stop experiencing the flow state. For that reason have in mind the following:
In fact the list can grow much more, but I'd like to set some starting points, to prevent information overload.
Try to set a flow state on user, and use the techniques that are previously described.
If your app lacks some of the above points, then probably your users will feel less motivated, and you may have to take action.
By the way, if you like, feel free to contribute with more bullet points on comments