You have probably heard the expression that your story “should be as long as it takes to tell the whole story”. With mobile travel and art guides, I encourage you to use your creativity to make all the points you want so your audience will remember your story.
I do suggest a general guideline of 250 to 400 words per experience. This translates into approximately two to three minutes of spoken audio. Of course, this is a guideline as some experiences can be shorter or longer. Being concise can be difficult but you want to hit the main points without repeating yourself. The philosophy of the guide is to arouse curiosity and stimulates your audience to inquire more deeply into the subject matter.
Some guide creators have effectively interjected recordings of oral history that can be listened to while looking at an object or just wandering. This can extend your experiences significantly but it can be an effective way of telling the story. I personally find oral histories compelling, especially when it is from a person who has a relationship to the subject matter.
As far as an overall guide length, I recommend between 10 to 20 experiences. While some people will be able to tell their story with less experiences, having more than 20 translates into roughly 40 to 60 minutes of listening or reading. Combine that time with travel time and your audience is approaching an hour and half to two hours which is a reasonable amount of time to hold someone’s attention.