Using only these supplies, which question can Victoria investigate with an experiment?
Do the deer eat fewer leaves from bean plants sprayed with coffee spray than from unsprayed bean plants? Do the deer eat more leaves from tomato plants or from squash plants? Do the deer eat fewer leaves from bean plants sprayed with garlic spray than from unsprayed bean plants?
Victoria has a garden that is sometimes visited by deer. She notices that the deer eat some plants in her garden more than others. She wonders what factors affect which plants the deer eat. So, she decides to design an experiment. She has the following supplies available:
a garlic spray used to keep garden pests away
four tomato plants
four bean plants
Experiments can be designed to answer specific questions. When designing an experiment, you must identify the supplies that are necessary to answer your question. In order to do this, you need to figure out what will be tested and what will be measured during the experiment.
Imagine that you are wondering if plants grow to different heights when planted in different types of soil. How might you decide what supplies are necessary to conduct this experiment?
First, you need to identify the part of the experiment that will be tested, which is the independent variable. This is usually the part of the experiment that is different or changed. In this case, you would like to know how plants grow in different types of soil. So, you must have different types of soil available.
Next, you need to identify the part of the experiment that will be measured or observed, which is the dependent variable. In this experiment, you would like to know if some plants grow taller than others. So, you must be able to compare the plants' heights. To do this, you can observe which plants are taller by looking at them, or you can measure their exact heights with a meterstick.
So, if you have different types of soil and can observe or measure the heights of your plants, then you have the supplies you need to investigate your question with an experiment!