Try It

Now that you have explored a process for determining the author’s purpose and how the author chooses to display information to serve the overall purpose, you will have a chance to practice your new learning as you read the following text about holiday lights.

As you read, remember to ask yourself:

  • What does the author want me to learn?
  • What is the central idea in the article?  What is the BIGGEST idea that the author is presenting to the reader?
  • What is the most important information to be gained from the text AND the visuals?

You will be examining major sections in the text in order to trace the author’s purpose through the use of text and visuals.  Read paragraphs 1 through 4 of the holiday lights article from Energy.gov “How Do Holiday Lights Work? Opens a new window” and complete the follow-up activities.

How Do Holiday Lights Work?

1 We're getting into the holiday spirit here at the Department of Energy. Our stockings are hung by the chimney with care and we have strings of lights decorating our cubicles. While stringing up lights, I wanted to learn how exactly holiday lights work. Here’s what I discovered.

2 Note that the primer below applies to incandescent light strands, which have been traditionally used to decorate our homes for the holidays -- and are a great way to learn about the flow of electric current. LED holiday light strands are becoming more popular, due to being sturdier, lasting longer and consuming 70 percent less energy than conventional incandescent light strands. It only costs $0.27 to light a 6-foot tree for 12 hours a day for 40 days with LEDs compared to $10 for incandescent lights. Learn more about LED lighting on Energy Saveropens a new window.

3 But now, back to incandescents. To start off, we have to understand how an incandescent light bulb works. In a simple circuit, electricity travels through a closed circuit, passing over a filament, causing it to glow brightly. The more current passes over a filament, the hotter it will get, the brighter it will burn, and quicker it will burn out. If the circuit is broken, or open, no electricity will pass over the filament and it will not light. If the current is too great, the filament will melt, or blow out, causing the circuit to become open.

4 But we want more than one light to shine on our Christmas tree or along the roofs of our homes. If you want to connect multiple light bulbs to the same power source, there are two ways to do that: either attach the lights in series or in parallel.

- Energy.gov - "How Do Holiday Lights Work?"