Question

A farmer divided his piece of land into 4 equivalent groups. The quality of the soil is the same across the 4 groups of land. He planted the same crop in all 4 groups of land and recorded the yield of the crop in all 4 groups for a 4 week period. Is the study observational or experimental? If it is an experiment, what is the controlled factor?

Answer 1

The student's scenario describes an experimental study where the controlled factors are the quality of the soil and other possible conditions like water, sunlight, and type of crop planted. Control groups, which do not receive the experimental treatment, are a vital component of such studies to isolate the effects of the independent variable.

Step-by-step explanation:

The study described by the student, wherein a farmer divides his land into 4 equivalent groups and plants the same crop across all groups to record yield over a period of 4 weeks, is an example of an experimental study. The reason it is experimental and not observational is that the farmer is actively controlling the conditions under which the crop is grown, as opposed to simply observing them without intervention.

In this experiment, the controlled factors include the quality of the soil, assumed to be the same across the four groups, and possibly other factors such as the amount of water, plant food, sunlight, and the type of crop planted, all of which are not explicitly stated but are implied to be controlled. The controlled factor is crucial in an experimental setup because it allows the researcher to isolate the effects of a specific variable they are testing (the independent variable) on the outcome of the study (the dependent variable), such as the yield of the crop.

An important aspect of experimental studies is the presence of a control group. This group would not receive the experimental treatment, which in the context of the provided scenarios could be the presence or absence of fertilizer, ensuring that any differences in outcome could be attributed to the fertilizer application.

Answer 2

1. It is an experimental study

2. The controlled factor is the quality of the soil

Step-by-step explanation:

1. It is an experimental study because the farmer is setting some initial conditions for the growing of the crop, if instead he was just recording the yield of a previous crop in which he didn't controlled any factor it would be an observational study.

Also we can say it is an experimental study because he has set an experimental design in which he controls the quality of the soil, and his method for gaining the information consist on recording the yield of the crop in 4 groups for 4 weeks, in this way he establish 4 repetitions in a 4 weeks period of time.

2. The controlled factor is the quality of the soil because it is a condition stablished before the experiment initiate and it is the same for all the study groups.