Using only these supplies, which question can Jeffrey investigate with an experiment?
Do watercolor paintings dry faster when placed next to a fan? Does a large watercolor painting or a small watercolor painting dry faster? Do watercolor paintings dry faster when they are placed inside or outside?
Jeffrey is painting watercolor pictures with his friend. An hour after they have finished, Jeffrey notices one painting is dry but the other is not. He wonders what factors affect how quickly watercolor paintings dry. So, he decides to design an experiment. He has the following supplies available:
two freshly painted watercolor pictures of the same size
his dining room table
a picnic table in his backyard
a heater
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!