Well, you all survived the odor of soaking beans, and I did not have to clean up any unexpected messes, thanks! Obviously we all noticed that the beans had changed, some more than others, but just how much change really occurred? There were a few goals that accompanied this lab as you remember, and they were:
v Accurately use the tools/equipment we use in science class
v Accurately use the metric system to make measurements in mass, length and volume
v Follow multiple directions without the assistance of Mr. Stark
v Make scientifically based hypotheses based upon clear observations made by the student
For this blog, I would like to focus on the final goal, making a scientifically accurate hypothesis based upon observation. This lab demonstrates a simple version of the scientific method along with the procedures one follows to create accurate data which can be easily sorted through. Look over the lab procedure you followed in class and answer the following questions to the best of your ability.
Any experiment typically has three types of variables; an independent variable (something that is changed by the scientist, there should only be one), a dependent variable (a quality that is being measured of the independent variable, i.e. change in mass), and finally a set of controlled variables (the procedures, tools and amounts which a scientist keeps the same during the experiment). For more on what the variables are in an experiment, check out this website.
1) What do you believe is the ONE independent variable in the bean lab? How do you know this is the ONE independent variable?
2) What do you believe are the dependent variables in the bean lab (there are more than one)? Why do you think we used these as the dependent variables for this lab?
3) What are the controlled variables in this experiment (use your procedure sheets to help you with this one)?
4) If I decided to have you test another type of bean with your experiment (Lima beans), which of the three types of variables did I change? Explain.
5) If I had students use 5ml of water to saturate their beans instead of 10ml of water, which of the variables did I change? Explain.
6) Let’s say you poured 5ml of water into 2 of the test tubes and 10ml of water into 3 of the test tubes. Would this experiment be fair? Explain why or why not.