Nicki Minaj goes to Silver River each week for 4 weeks and collects 5 samples of water to test the pH. What is this an example of?

Wiz Khalifa was mixing a batch of glue and borax solution to make silly putty and discovered a new substance that glows in the dark. He gave Cardi B his specific amounts of ingredients and the steps of his procedure. He asked Cardi B to try the experiment to see if she gets the same results. This is an example of what?

Ms. Tantillo has been reading about another scientist’s research in a physics journal. She plans to do these experiments herself and see if she gets the same result. This is an example of what?

Post Malone has taught his pet rat to run a maze. He thinks that the rat will go faster if he puts its favorite treat at the end. He has the rat run the maze ten times with the favorite treat and ten times with a regular food pellet. He uses a stopwatch to measure how long it takes for the rat to get to the reward. This is an example of what?

Alisson does an experiment to see how long it takes for a teaspoon of sugar to dissolve in a cup of water. She does this three times and then asks Carpaur to copy her experiment to see if he gets similar result. What is Carpaur doing?

Ms. Hayward conducts a study to see which period students are most late to. She does this for five days. This is an example of...