This chart shows the experimental design of four students who are all observing what kind of bird seed birds tend to eat more often. Student 1 Student 2 Student 3 Student 4 - Performed the experiment once - Used the same area, same time of day, and same amount of seeds - Repeated the experiment 5 times - Used the same area, different time of day, and different amount of seeds - Repeated the experiment 2 times - Used the same area, different time of day, and different amount of seeds - Repeated the experiment 5 times - Used the same area, same time of day, and same amount of seeds Which student is the most likely to have reproducible results? Student 1 Student 2 Student 3 Student 4

Explanation:

Arrange the data of the chart for better understanding:

Student 1

- Performed the experiment once

- Used the same area, same time of day, and same amount of seeds

Student 2

- Repeated the experiment 5 times

- Used the same area, different time of day, and different amount of seeds

Student 3

- Repeated the experiment 2 times

- Used the same area, different time of day, and different amount of seeds

Student 4

- Repeated the experiment 5 times

- Used the same area, same time of day, and same amount of seeds

The variable under study or investigated is the kind of bird seed birds tend to eat more often.

When you design your expetiment, you must make sure that only one variable is manipulated (changed) at a time, while keeping other variables under control, i.e. unchanged.

If other factors vary you cannot draw valid conclusions about the effect of your independent variable on the dependent variable.

The reproducibiilty of your data, will be more likely if you report all the variables kept under control, so that new experiments are performed under the same conditions.

By using the same area, same time of day, and same amount of seeds, student 4 kept most variables controlled, making the results more reproducible.

Also, by repeating the experiment 5 times, the student 4 reduced the effect of the random errors, making the results more reproducible.

Hence, student 4 is the most likely to have reproducible results.

student 4

Explanation:

Student 4

- Repeated the experiment 5 times

- Used the same area, same time of day, and same amount of seeds

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.