An experiment was conducted to test which kind of fertilizer was the best.?

Question

Plants in Group A and Group B was given different fertilizer. Suppose the plants in B was grown in full sunlight while the plants in the control group and Group B was grown in partial shade. How would this influence the interpretation of the results?

Answer 1

The problem with this experiment is that there are two variables involved, namely the amount of light and the type of fertilizer. When conducting scientific experiments it is always a good idea to only have one thing variable and all others kept constant. In this case if you want to know about the influence of fertilizer type then it would be necessary to keep amount of light constant or at least the same for the two different fertilizers. If fertilizer A made the plant grow better than fertilizer B under the same light conditions, it is possible that if the plants were grown using fertilizer B but at higher light intensity they would do better because of the better light conditions. Of course plants receiving full sunlight might be photoinhibited by too much light regardless of the fertilizer that they have, while those that are shaded might have too little light to grow properly.