Question

Boosting preemies Do blood-building drugs help brain development in babies born prematurely? Researchers randomly assigned $53$babies, born more than a month premature and weighing less than $3$pounds, to one of three groups. Babies either received injections of erythropoietin (EPO) three times a week, darbepoetin once a week for several weeks, or no treatment. Results? Babies who got the medicines scored much better by age $4$on measures of intelligence, language, and memory than the babies who received no treatment.

a. Explain how this experiment used comparison.

b. Explain the purpose of randomly assigning the babies to the three treatments.

c. Name two variables that were controlled in this experiment and why it was beneficial to

control these variables.

d. Explain how this experiment used replication. What is the purpose of replication in this

context?

Short answer

(a) The experiment uses comparison by comparing babies giving injections, given medicines, and some babies having no treatment.

(b) The purpose of randomly assigning babies is to give the results that are accurate.

(c) The two variables that are controlled are pre-mature and weight and these are beneficial to predict best result.

(d) The treatment use replication because treatment is given to different babies some having weight more than three pounds while some less.

Step-by-step solution

Part (a) Step 1: Given Information

We are given the experiment of research that deals with the babies having injection medicine and no treatment, and we have to find out how this experiment is using comparison.

Part (a) Step 2: Explanation

According to the question, the researchers are using the experiment on babies who are already pre-mature and the result will be affected by the injections of erythropoietin, by taking darbepoetin or having no treatment.

Hence, in this way the researchers are using comparison operator.

Part (b) Step 1: Given Information

We are given an experiment of research that deals with the babies having injection medicine and no treatment, and we have to find out the purpose of randomly assigning the babies.

Part (b) Step 2: Explanation

According to the question, there are fifty three babies and researchers want to observe the improvement in babies by choosing three ways: giving injections , taking medicines, or no treatment, and for that, researchers have to choose the babies randomly for giving injections and medicines and for no treatment.

Part (c) Step 1: Given Information

We are given an experiment of research that deals with the babies having injection medicine and no treatment, and we have to find out the purpose of controlling two comparable variables.

Part (c) Step 2: Explanation

According to the question, there are two variables: pre-mature and weight. As the weight increases, the babies will be more intelligent, have more memory, and their languages will be more accurate. Hence, the increase in weight of pre mature will affect the results. So, it is necessary to control these two variables.

Part (d) Step 1: Given Information

We are given an experiment of research that deals with the babies having injection medicine and no treatment, and we have to find out how this experiment has used replication.

Part (d) Step 2: Explanation

According to the question, babies are researched by three different things, and for two of those treatments, eighteen babies will be used, and for the other seventeen babies. Hence, this proves that an experiment uses replication because it is necessary to use to have an accurate result.