Question

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.

How was replication used in this experiment?

A) All of the babies were premature with a birth weight of less than three pounds.

B) Babies were measured on multiple variables – intelligence, language and memory.

C) (INCORRECT) The babies were randomly assigned to the different treatments.

D) There were 53 infants in the study, presumably about 17 infants in each treatment group.

E) There were three different treatments used in the experiment.

Answer 1

Replication in the study was achieved by having a large group of similarly characterized subjects, by measuring consistent variables across participants, and by having roughly equal numbers of participants in each treatment group, enhancing the reliability of the findings.

Step-by-step explanation:

In the experiment examining the effects of blood-building drugs on brain development in prematurely born babies, replication was demonstrated by having multiple subjects that had similar characteristics, specifically all the babies were premature and weighed less than three pounds (Option A).

Additionally, the replication aspect appears in the consistent measurement of variables across all participants of the study, as the babies were evaluated on intelligence, language, and memory (Option B).

Lastly, the replication can also be seen in the number of infants per treatment group as there were 53 infants in the study, divided roughly equally across the three different treatments which included administering erythropoietin (EPO), darbepoetin, or giving no treatment (Option D and E). Replication is crucial in scientific research to ensure that results are reliable and not due to chance or outlier effects.