Chapter 1

A(n) differs from the control group by the one variable that is being tested in the experiment.

experimental group

A(n) is a proposed, testable explanation for an observation.

hypothesis

Choose the single best answer.) The most trustworthy source of scientific information is:

peer-reviewed scientific journals

Which of the following is the best definition for the term hypothesis? (Choose the single best answer.)

A hypothesis is the proposed answer to a question that was derived from an observation.

You like some chocolate chip cookie recipes better than others.

Observation

Which of the following is a scientific hypothesis? (Choose the single answer that is a testable hypothesis, even if it is not a correct hypothesis!)

People catch colds because of exposure to cold temperature.

You make one batch of cookies with regular flour and another with cake flour.

Experiment

Consider an experiment in which human subjects are given a pill to test its effectiveness on reducing the duration of a cold. Which of the following is the best way to treat the control group? (Choose the single best answer.)

Give the control group a placebo (a pill that does not affect colds).

Cake flour works better than regular flour.

Hypothesis

Does the type of flour you use make a difference?

Question

Using cake flour makes the cookies soft, which you prefer.

Results

(Choose the single best answer.) A scientific hypothesis has all of the following features EXCEPT that it is:

able to be proven true.

A scientific theory is:

an explanation supported by a very large amount of experimental evidence.

A(n) in an experiment yields data against which other groups are compared.

control group

(Choose the single best answer.) The purpose of double-blind experiments is to:

minimize bias in the results of an experiment.

Choose the single best answer.) An experiment is called double-blind when:

neither the subjects nor the technicians know who is in the experimental group and who is in the control group.

(Choose the single best answer.) An experimental result is called statistically significant when:

the result is unlikely to be due to chance alone.

(Choose the single best answer.) The most effective control subjects in a test of an experimental treatment are:

treated identically to the experimental subjects but not given the experimental treatment.

A(n) is a factor that changes during an experiment.

variable