2024-10-21
Before we analyze our data, we should be very clear about our research hypotheses. Please write down your research hypotheses. These will be:
For example…
Basic analysis plan…
Most people believe that country air is better to breather than city air, but how would you test it? You might start by choosing a response that narrows down what you mean by “better.” One feature of healthy lungs is tracheobronchial clearance—how fast they get rid of nasty stuff. To test this idea, investigators found 7 sets of mono-zygotic twins where one was living in the country and one in the city. Each person inhaled an aerosol of radioactive Teflon particles. Then the level of radioactivity was measured once right after inhaling, and again an hour later. The percent of the original radioactivity remaining was calculated.
This experiment is interested in the blood concentration of a drug after it has been administered. The concentration will start at zero, then go up, and back down as it is metabolized. This curve may differ depending on the form of the drug (a solution, a tablet, or a capsule). We will use three subjects, and each subject will be given the drug three times, once for each method. The area under the time-concentration curve is recorded for each subject after each method of drug delivery.
It is reasonable to assume that the structure of a sugar molecule has something to do with its food value. An experiment was conducted to compare the effects of four sugar diets on the survival of leafhoppers. The four diets were glucose and fructose (6-carbon atoms), sucrose (12-carbon), and a control (2% agar). The experimenter prepared two dishes with each diet, divided the leafhoppers into eight groups of equal size, and then randomly assigned them to dishes. Then she counted the number of days until half the insects had died in each group.
As a rule it takes about a year before a baby takes its first steps alone. Scientists wondered if they could get babies to walk sooner by prescribing a set of special exercises. They decided to compare babies given special exercises with a control group of babies. But the scientists recognized that just showing an interest in the babies and their parents could cause a placebo effect. That is, the attention alone could influence parents and their babies in ways that would shorten the time to walk. 24 babies were randomly assigned to one of four conditions:
They recorded the age (in months) the babies first walked.
Male albino laboratory rats are used routinely in many kinds of experiments. This experiment was designed to determine the requirements for protein in their food. Specifically, the experiment is interested in testing five levels of protein (8.68, 12, 15, 18, and 21% of diet). 50 baby rats were randomly assigned to each of the 5 conditions. Body weight and food consumption were measured twice weekly, and the average daily weight gain over 21 days was recorded.
Male albino laboratory rats are used routinely in many kinds of experiments. This experiment was designed to determine the requirements for protein in their food. Specifically, the experiment is interested in testing five levels of protein (8.68, 12, 15, 18, and 21% of diet). Baby rats were separated into ten groups of 5 to form groups of approximately the same weight. The 5 rats in each group were randomly assigned to each of the 5 conditions. Body weight and food consumption were measured twice weekly, and the average daily weight gain over 21 days was recorded.