You must connect with your readers in the introduction, and continue to keep them in mind throughout the essay. If you write as if you are talking to an empty space, your audience will lose interest.  If they stop reading, you cannot prove your point.

       Introductions to academic essays should include the following:
LEAD-IN:  Several  sentences that lay comprehensive background through description, anecdote, or scenario.
THESIS: One clear sentence that succinctly states the topic, purpose, or claim.
LISTING: ONE grammatically parallel sentence that introduces all three arguments/points.

First, determine PURPOSE of introduction by examining your topic.     

• If your topic is narrow in scope–Make the topic relevant
• If your topic is not well-known or complicated– Make the topic understandable
• If your topic is well-known and controversial – Build trust by finding common ground or conceding a point

Second, Determine CONTENT that will achieve identified purpose.     

• Definitions of uncommon terminology
• Definitions of uncommon ideas, organizations, laws, etc.
• Information about history of issue
• Information about current situation
• A concessionary point about the issue
• Identification of  common ground held by people on both sides of the issue

Third, Choose MODE (specific strategy) based upon content.     

• Descriptions & Explanations of words, concepts, history, current situation etc.
• Anecdote: Real story about an actual person or event that illustrates major points
• Scenario: Writer-created situation that illustrates the points that will be covered in the paper