We've talked about active learning as an alternative to traditional lecture-style teaching. But you can use active learning strategies in the lab as well. Labs may seem like "cookbook" experiments with a prescribed set of steps and one predetermined outcome. There is little room for true experimentation. Students may feel that the focus is on getting the right answer rather than really learning from the experience.
Simple tweaks can help alleviate this problem. For example, you might try scheduling a lab first and then working with your students on theory. Because students don't know what to expect, they will approach labs with genuine curiosity rather than a set of steps they must follow to get to a predetermined outcome.
Another idea is to ask students to make predictions before they begin a lab so that they are more invested in the outcome. Your students may also be more interested in lab activities as they relate to work or problems in the world.
Devoting more time to a complex problem can result in richer learning than trying to cover every detail of a topic.