osmosis and diffusion

he mass and length of the potato piece must be kept the same in each experiment primarily because they affect the surface area of the piece, and varying surface area could have a great effect on the rate of osmosis. This is because in an experiment where the potato chip has a large surface area, there is a larger area of partially permeable membrane and therefore more opportunity for water particles to pass through. I will keep the surface area the same by keeping the mass and length of the potato piece the same in each instance, by measuring and cutting it carefully.
I am fairly sure that my results are reliable as they proved my hypothesis but I had two anomalous results. I think this is because as we did the experiment over 3 days, we did not have a chance to use the same potato as I had planned to do. All potatoes do not have the same tissue structure and also concentration of sugar in different potatoes is different. I am sure that excess solution cannot be the reason for anomalous results because I wiped it off before I measure the mass of the potatoes. I believe that another reason for there to be anomalous results is that as I was the only person working on the experiment, some of the experiments stayed in the solution longer than the others.
I believe this can affect the reliability of my results. Lastly I think that if I was provided with better equipment to work with than I could make this experiment more accurate and reliable. Below is a graph to compare the reliability of my results. Below is a graph comparing the results of the two experiments I carried out.