Age could affect reaction time, as well as nicotine. How could the researcher have controlled for this potential extraneous variable?
a) by randomly selecting participants from the population
b) by counterbalancing the order of stimulus presentation across participants
c) by matching each participant in the experimental group with a participant of the same age in the control group
d) by using a different dependent variable
C
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Once newspaper publishers and editors freed themselves from party control
a. most of them quickly went out of business without the economic support of the parties. b. they were frozen out of having any say in national politics. c. the readership of the papers dropped sharply. d. they discovered that they were able to influence public opinion and, in turn, national politics.
Examples of public goods include all of the following EXCEPT
a. defense b. infrastructure c. laws d. telephone service