Always when one writes, one must consider the audience. So, if the readers are children a more informal tone is preferable and the address of the introduction should be something to which they can relate. On the other hand, if the essay is more formal, such as an address to members of the film industry or businessmen, a more mature and critical approach to the topic should be taken.
Assuming, then, that children are the ones whom the writer addresses, the introduction should hook their attention. Often beginning with a question will motivate children to continue reading:
Have you ever experienced a tornado? Can you imagine if your house was lifted with you hiding in it? In The Wonderful Wizard of Oz, a girl named Dorothy and her little dog Toto are in just such a situation:
The house whirled around two or three times and rose slowly through the air. Dorothy felt as if she were going up in a (hot air) balloon.
The vicious cyclone carries Dorothy's house a long ways as it leaves the earth. Exhausted, Dorothy falls asleep with Toto in her arms until the house is gently set down by the dying winds. Awakening, the girl finds herself in strange, new land of fascinating beauty.
It is at this point that the writer introduces the thesis, which is a general statement with three opinions about this statement which will be proven with analysis and details from the novel. With this introduction, a character analysis will logically follow, one in which the writer could point to Dorothy's brave mind and her determination. Thesis: Despite being lost in another world, Dorothy is determined to find her way back, and in so doing she learns much about the importance of friendship, family, and home. The thesis is the final sentence of the introductory paragraph.
The Wizard of Oz is really all about Dorothy. All of the other characters are there to support her arc in the story and for her to learn what she needs to from this adventure. So the introduction should focus on her and touch on how each step of her travels gets her close to figuring out what is really important. This being of course in simple terms “There’s no place like home”. If this is an intro for a larger paper than expand on this idea or focus on another theme that is in your thesis.
Even though most people know the story, don’t give away the ending, just in case. Focus on a story about a young girl who learns what is really important to her by running away from it. In a fantastical new world she meets a myriad of characters like the bubbling scarecrow, the empathetic tin man, and the cowardly lion. Through the time she spends with her new friends she gains a new perspective on friendship and family and the importance of both.