Scientific Method
A scientist changes the amount of fertilizer and measures plant height. What are the IV and DV?
IV: amount of fertilizer. DV: plant height.
A scientist tests three soil types on sunflowers, keeping water, sunlight, and pot size the same. What type of experiment is this, and why?
Controlled experiment — one variable is deliberately changed while the others are kept constant.
A scientist predicts a new fertilizer will work. While collecting data, she pays more attention to the plants that grew taller and overlooks plants that did not. What type of bias is this?
Confirmation bias — she is favoring evidence that supports what she already believes.
Ice cream sales and pool visits both increase during summer. A student concludes that eating ice cream causes people to swim. What is wrong with this conclusion?
Correlation ≠ causation. A third variable, hot weather, could cause both to increase.
Your experiment produces data that does not support your hypothesis. Your measurements were reliable and the experiment was well designed. Did your experiment fail? Explain.
NO. A hypothesis does not have to be supported for an experiment to be successful. The evidence helps scientists revise explanations and ask new questions. Science involves uncertainty and revision.