Question

Lyndon is investigating whether putting plastic on her windows will help seal out cold winter drafts. She covers a window on the south side of her house with plastic and measures the inside temperature near the window. She also measures the inside temperature near a window without plastic on the north side of her house. The windows are the same size and design. Why is this not an ideal controlled investigation?

Answer 1

Answer:

B.  

The drafts at each window may be different because the windows aren’t near each other.

Answer 2

Lyndon's experiment has TWO independent variables:

-- covered with plastic  / 
                not covered with plastic

-- measure temperature on the south side  / 
                measure temperature on the north side.

When Lyndon observes the results of her experiment, she can't tell
WHICH variable produced the results she observes.