a double-blind experiment was conducted to evaluate the effectiveness of the salk polio vaccine. the purpose of keeping the diagnoising physicians ignorant of the treatment statsus of the experimental subjects was to..
c. eliminate a polssible source of bias
under which of the following conditions is it preferable to use stratified rand sampling rather than simple random sampling?
c. the population can be divided into strata so that the individuals in each stratum are as much alike as possible
3. the sampling frame is
c. all members of the national education association
spaghetti
d. matched pairs design
the reason that blocking is sometimes used in experimentation is to
e. reduce variability arising from random assignment
6. a test is run to compare two calc books, one with a traditional approach and one with a reform approach. a state university agrees to use the traditional text.
c. no because there is a confounding variable: large public university vs. small private
7. a pharmacist wants to study the effect of temp on the potency of a headache pain reliever
e. specific temp, pill, relief time
8. just before the pres election of 1936 the magazine literary digest predicted
c. undercoverage
each person in a SRS of 2000 received a survey
e. those who did respond may differ in some important way from those who did not respond
10. an author wrote a book that advocated the playing of classical music to little children
e. III and IV
in an experiment, an observed effect so large that it would rarely occur by chance is called
c. statistically significant
a sportswriter wants to know how strongly lafl residents suport the local minor league baseball team
a. all residents of lafl
use scenario 4-8. which of the following best describes the inferences the researches can make based in his results?
a. they can make inferences about cause and effect, but not about the populations from which the samples were taken
use scenario 4-8. the experimental units are
b. 100 adult volunteers
since many individuals walk around their homes in their socks, a manufacturere has reated a material for socks....... the manufacturer wishes to test this belief over a period of a month. given a group of volunteers, which of the following designs will be
d. for each volunteer, randomly choose which foot wears a cotton sock, while the other foot wears a sock made of the new material. compare the wear on the socks at the end of the month
the essential difference between an experiment and an observational study is that
e. an experiment imposes treatments on the subjects, but an observational study does not
we divide the class into two groups; first year students and others. we then take random samples from each group. this is an example of
d. stratified random sampling
18 what is wrong with the experimental design?
the type of car is a potential confoudning variable
telephone poll-takers call near dinner time because most people are at home. this is an effort to avoid
d. nonresponse
20. use scenario 4-7. the brand of pellets is
c. the explanatory variable
your school will send a delegation of 35 seniors to a student life convention. 200 girls and 150 boys are eligible to be chosen. if a sample of 20 girls and separate sample 15 boys are each selected randomly, it gives each senoir the same chance to be cho
yes, this is an srs. an srs is designed
a.
cluster sample
b.
stratified random sample
c.
convenience sampled.
srs
e. systematic sampling
a double-blind experiment was conducted to evaluate the effectiveness of the salk polio vaccine. the purpose of keeping the diagnoising physicians ignorant of the treatment statsus of the experimental subjects was to..
c. eliminate a polssible source of bias
under which of the following conditions is it preferable to use stratified rand sampling rather than simple random sampling?
c. the population can be divided into strata so that the individuals in each stratum are as much alike as possible
3. the sampling frame is
c. all members of the national education association
spaghetti
d. matched pairs design
the reason that blocking is sometimes used in experimentation is to
e. reduce variability arising from random assignment
6. a test is run to compare two calc books, one with a traditional approach and one with a reform approach. a state university agrees to use the traditional text.
c. no because there is a confounding variable: large public university vs. small private
7. a pharmacist wants to study the effect of temp on the potency of a headache pain reliever
e. specific temp, pill, relief time
8. just before the pres election of 1936 the magazine literary digest predicted
c. undercoverage
each person in a SRS of 2000 received a survey
e. those who did respond may differ in some important way from those who did not respond
10. an author wrote a book that advocated the playing of classical music to little children
e. III and IV
in an experiment, an observed effect so large that it would rarely occur by chance is called
c. statistically significant
a sportswriter wants to know how strongly lafl residents suport the local minor league baseball team
a. all residents of lafl
use scenario 4-8. which of the following best describes the inferences the researches can make based in his results?
a. they can make inferences about cause and effect, but not about the populations from which the samples were taken
use scenario 4-8. the experimental units are
b. 100 adult volunteers
since many individuals walk around their homes in their socks, a manufacturere has reated a material for socks....... the manufacturer wishes to test this belief over a period of a month. given a group of volunteers, which of the following designs will be
d. for each volunteer, randomly choose which foot wears a cotton sock, while the other foot wears a sock made of the new material. compare the wear on the socks at the end of the month
the essential difference between an experiment and an observational study is that
e. an experiment imposes treatments on the subjects, but an observational study does not
we divide the class into two groups; first year students and others. we then take random samples from each group. this is an example of
d. stratified random sampling
18 what is wrong with the experimental design?
the type of car is a potential confoudning variable
telephone poll-takers call near dinner time because most people are at home. this is an effort to avoid
d. nonresponse
20. use scenario 4-7. the brand of pellets is
c. the explanatory variable
your school will send a delegation of 35 seniors to a student life convention. 200 girls and 150 boys are eligible to be chosen. if a sample of 20 girls and separate sample 15 boys are each selected randomly, it gives each senoir the same chance to be cho
yes, this is an srs. an srs is designed
a.
cluster sample
b.
stratified random sample
c.
convenience sampled.
srs
e. systematic sampling