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Chapter 4: Q 47. (page 253)

Learning biology with computers An educator wants to compare the effectiveness of computer software for teaching biology with that of a textbook presentation. She gives a biology pretest to each group of high school juniors, then randomly divides them into two groups. One group uses the computer, and the other studies the text. At the end of the year, she tests all the students again and compares the increase in biology test scores in the two groups.

(a) Is this an observational study or an experiment? Justify your answer.

(b) If the group using the computer has a much higher average increase in test scores than the group using the textbook, what conclusions if any, could the educator draw?

Short Answer

Expert verified

Part (a) Observational study.

Part (b) Since the intake of mother chocolate helps clarify the temperament of the baby.

Part (c) No, there is chance lurking variable.

Step by step solution

01

Part (a) Step 1: Given information

We must evaluate whether this is an observational or an experimental study.

02

Part (a) Step 2: Concept

Observational research looks at people and assesses factors of interest without trying to affect their responses.

03

Part (a) Step 3: Explanation

Because an observatory analysis retrieves information on the possible impact of individuals on a technique, this was an observational study. When the investigator has no influence over whether subjects are assigned to a treatment group or a control group. The researchers also questioned their chocolate consumption and attitudes toward newborns.

04

Part (b) Step 1: Explanation

Because chocolate consumption by the mother helps to clarify the baby's disposition. The intake of mother chocolate and the nature of the infant are the explanation and response.

05

Part (c) Step 1: Explanation

No. Because this is an observational study, it is impossible to conclude that chocolate consumption during pregnancy consistently results in children with healthy temperaments. If the temperament is different, a hidden element may have an impact.

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