The level of enjoyment experienced during a trip is obviously subjective, and as such can be difficult for a leader to gauge, particularly when it differs between group members. Whenever possible, making the objectives and details of a trip explicit to prospective participants may help to match their expectations to yours. It is important to remember that each group member may be feeling differently about the trip. What is a leisurely stroll up a gentle slope to one person may be an endless struggle up an interminable mountain to the next.
Another challenge for you, the leader, is to understand that different participants may have quite different objectives. For some, the physical challenge of a long, steep climb is reward in itself, for others a gentle ramble through the orchids of spring may be pure bliss. Your task is to get inside the head of your group members, understand what makes them tick, and point them in the right direction.