1 A small 3-ounce piece of meat has about 21 grams of protein. A typical 8-ounce piece of meat could have over 50 grams of protein. 2  One 8-ounce container of yogurt has about 11 grams of protein. 3  One cup of milk has 8 grams of protein.  One cup of dry beans has about 16 grams of protein.
All of these aspects of peanut growth can be measured and can be used as dependent variables in an experiment. There are different dependent variables possible in an experiment. The investigator can choose the one he thinks is most important, or he can choose to measure more than one dependent variable.
Experiments vs. Observational Studies In an experiment investigators apply treatments to experimental units (people, animals, plots of land, etc.) and then proceed to observe the effect of the treatments on the experimental units. In a randomized experiment investigators control the assignment of treatments to experimental units using a chance mechanism (like the flip of a coin or a computer's random number generator). 2 Experiments vs. Observational Studies (cont.) In an observational study investigators observe subjects and measure variables of interest without assigning treatments to the subjects. The treatment that each subject receives is determined beyond the control of the investigator. For example, suppose we want to study the effect of smoking on lung capacity in women. 3 Experiment