WGU C955 Probability and Statistics Objective Assessment Exam ()
with Questions and Revised Answers, 100% Guarantee Pass (Updated)
Simpson's Paradox - ANSWER-When split up, each data set can have a pattern which
goes away when all the data is combined.
Only way to prove causation - ANSWER-Experiments, because they account for lurking
variables
Observational study - ANSWER-A type of study where we measure or survey members of
a sample without trying to affect them. Cannot prove causation.
Experimental study - ANSWER-A study where you split subjects up randomly and impose
a change on one group to study the effect; can prove causation
Prospective study - ANSWER-Is a study that's done over time to find results / A study
watching for outcomes during the study period
Retrospective study - ANSWER-A study that looks backwards to assess outcomes and
possible causes after the fact
Control group - ANSWER-randomly assign people or things to groups. One group
receives a treatment and the other group does not. This is the group that does not
receive treatment
Placebo - ANSWER-A substance or procedure that has no effect used for comparison to
the real substance or procedure
Placebo effect - ANSWER-A beneficial effect produced by the belief of the
patient/subject, not by the intervention itself.
Experimenter effect - ANSWER-When the persons running an experiment affects its
results by influencing the subjects inadvertently
, Open question - ANSWER-A question that gives the responder freedom to answer in
many different ways -- harder to analyze with statistics.
Closed question - ANSWER-A question with limited choices, e.g. multiple choice or
yes/no. Easier to analyze statistically.
Unbalanced response - ANSWER-Giving more options that are negative than positive
options (or vice versa) which biases the responses towards the more common option
Matched pairs - ANSWER-Grouping two similar subjects and giving different
treatments/procedures to each in order to compare the differences. For example,
having one twin take a medication while the other twin does not.
Blind experimental study - ANSWER-When information of a study isn't revealed to the
participants
Double Blind Study - ANSWER-When information of study is hidden from the researcher
and the participant.
Population - ANSWER-The entire group you are trying to describe or understand.
Sampling frame - ANSWER-List of group from which you choose your sample.
Sample - ANSWER-The group that is actually picked to be included in a study
Simple random sample - ANSWER-making a selection by following a random pattern and
selecting without replacement. Unbiased.
Systematic sample - ANSWER-Sample is selected by listing the sampling frame, then
making a selection by following a simple pattern (eg. Every 20th name). Unbiased.
Voluntary sample - ANSWER-Members of the sample may choose not to respond. Similar
with Questions and Revised Answers, 100% Guarantee Pass (Updated)
Simpson's Paradox - ANSWER-When split up, each data set can have a pattern which
goes away when all the data is combined.
Only way to prove causation - ANSWER-Experiments, because they account for lurking
variables
Observational study - ANSWER-A type of study where we measure or survey members of
a sample without trying to affect them. Cannot prove causation.
Experimental study - ANSWER-A study where you split subjects up randomly and impose
a change on one group to study the effect; can prove causation
Prospective study - ANSWER-Is a study that's done over time to find results / A study
watching for outcomes during the study period
Retrospective study - ANSWER-A study that looks backwards to assess outcomes and
possible causes after the fact
Control group - ANSWER-randomly assign people or things to groups. One group
receives a treatment and the other group does not. This is the group that does not
receive treatment
Placebo - ANSWER-A substance or procedure that has no effect used for comparison to
the real substance or procedure
Placebo effect - ANSWER-A beneficial effect produced by the belief of the
patient/subject, not by the intervention itself.
Experimenter effect - ANSWER-When the persons running an experiment affects its
results by influencing the subjects inadvertently
, Open question - ANSWER-A question that gives the responder freedom to answer in
many different ways -- harder to analyze with statistics.
Closed question - ANSWER-A question with limited choices, e.g. multiple choice or
yes/no. Easier to analyze statistically.
Unbalanced response - ANSWER-Giving more options that are negative than positive
options (or vice versa) which biases the responses towards the more common option
Matched pairs - ANSWER-Grouping two similar subjects and giving different
treatments/procedures to each in order to compare the differences. For example,
having one twin take a medication while the other twin does not.
Blind experimental study - ANSWER-When information of a study isn't revealed to the
participants
Double Blind Study - ANSWER-When information of study is hidden from the researcher
and the participant.
Population - ANSWER-The entire group you are trying to describe or understand.
Sampling frame - ANSWER-List of group from which you choose your sample.
Sample - ANSWER-The group that is actually picked to be included in a study
Simple random sample - ANSWER-making a selection by following a random pattern and
selecting without replacement. Unbiased.
Systematic sample - ANSWER-Sample is selected by listing the sampling frame, then
making a selection by following a simple pattern (eg. Every 20th name). Unbiased.
Voluntary sample - ANSWER-Members of the sample may choose not to respond. Similar
