Tangible user interfaces (TUIs) have been the focus of much attention recently in the HCI and learning communities. Although TUIs seem to intuitively offer potential to increase the learning experience, there have been questions about whether they actually impact learning positively. TUIs offer new ways of interactions and it is essential to understand how the design choices made for these new interactions affect learning. One element that is key in the learning process is how and when feedback is provided. In this article, we focus on the effect of co-located immediate process-level feedback on learning. We report the results of a study in which 56 participants used a TUI to complete tasks related to the training of spatial skills. Half of the students accomplished the tasks with immediate and co-located feedback from the system, while the other half of the students did not receive any feedback. Results show that participants who did not receive feedback manipulated less, reflected more, and in the end learned more than those who received feedback.