Reactive getData() causes helper to be executed 3 times

I'm using getData() as described in the docs, as part of a helper. I've noticed that this helper is run three times (instead of one time), if a new search is executed. This causes problems, because I would like to animate the display of the results. If you don't animate it, you won't notice the 3 renderings, but if you animate, you do. What may cause these multiple calls?
