Final answer:
In experimental setups, changes in factors such as the amount of water, plant food, soil, sunshine, and the soil type are observed to determine their effects. Variables such as individual plant characteristics, soil temperature, water evaporation, and pests should be controlled to ensure valid results.
Step-by-step explanation:
The factors that changed throughout the experiment could include a variety of elements, such as the amount of water, amount of plant food, amount of soil, amount of sunshine, or the type of soil. These are the variables that can be manipulated to observe different outcomes in experimental setups, especially in biological or environmental science experiments. When evaluating the setup of an experiment, the factors that may have varied and were not controlled can significantly impact the results. These include individual plant variation, soil temperature influenced by the color of the containers, water loss through evaporation, and potential effects of insects on the plants. Controlling these variables is crucial for ensuring that the results are due to the controlled factors and not these uncontrolled ones.
To conduct a valid and reliable experiment, it is important to identify the dependent and independent variables, and keep all other variables constant, which are known as controlled variables. In an experiment testing materials over a temperature range, one might ask if a change of phase takes place for any of the tested materials, which requires careful control and observation of the variables involved.
Furthermore, experiments related to heat transfer refer to three essential factors affecting heat transfer necessary to change an object's temperature. These might involve conduction, convection, and radiation.