I could buy a flower seed packet from grocery outlet. I open the packet finding 10 sunflower seeds, i used a even number generator to determine what amount of seeds to plant. The generator lands on 4. i plant 2 sunflower seeds in 2 pots of soil and plant the other 2 sunflower seeds in 2 pots of sand. I also will water each plant every day and ensure each plant has the same amount of sunlight. Then I can measure the height of the sunflowers after one month

Question

Where in your experiment would random assignment occur?

Answer 1

In your experiment, random assignment would occur during the selection of which seeds to plant in which type of medium (soil or sand). Since you are using an even number generator to determine how many seeds to plant (which in this case lands on 4), you would ideally want to assign each of the 4 seeds randomly to one of the two types of planting medium.

For example, if you had a method to randomly assign (such as flipping a coin for each seed or using a random number generator), you could have:

1. Seed 1 - Soil
2. Seed 2 - Sand
3. Seed 3 - Soil
4. Seed 4 - Sand

This random assignment would help ensure that any differences in growth (height of the sunflowers after one month) can be attributed to the type of growing medium used rather than any other variables. In your description, it appears you have predetermined how the seeds are planted (2 in soil and 2 in sand), which is why random assignment is important for a controlled experiment.