Background: Most workplace learning is informal. However, some employees struggle to execute informal learning strategies effectively because they lack the necessary knowledge or skills or use their knowledge and skills ineffectively or not at all. Objectives: We examined the effects of computer-based micro-learning interventions that provide strategy knowledge, prompts, or both, on strategy knowledge, strategy use, and goal achievement--to compensate for these deficits. Methods: A total of 122 employees were randomized into four interventions groups, that is, knowledge, prompts, both, and waiting control group, for a longitudinal micro-learning training experiment. The participants received 10 micro-learning nuggets over a month. Results and Conclusion: Compared with the control group, results of the interventions suggested that providing knowledge led to more declarative knowledge. Surprisingly, prompts resulted in more declarative knowledge. Combined interventions led to greater declarative knowledge, but no further synergetic effects could be observed. Over the training course, results showed positive, cubic effects on strategy use and for individual goal achievement for the prompts and combined intervention group. Qualitative data suggest a self-assessment adjustment of strategy use. In future studies, interventions could be custom-designed to compensate for the different deficits.