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STT Exam 1 Questions and Correct Answers
Explanatory variable Ans: - The variable that is manipulated by
researchers
- The variable that is thought to cause a different in an outcome
Response Variable Ans: - The variable that is observed by
researchers
- The variable that 'answers' the research question
In the early 1950's there was limited evidence that a vaccine
developed by Jonas Salk was both safe and effective, based on
small studies. A large-scale trial was needed to assess the
effectiveness of the vaccine. What is the explanatory and response
variable? Ans: Explanatory: If you get the vaccine or not
Response Variable: Immune response to polio/do you get it or not
Treatment Group Ans: The group of subjects in a study that
receives a treatment
Control Group Ans: A separate group of subjects in a study that
does not receive the treatment
Confounding Factors Ans: hidden variables that correlate in some
way with the independent or dependent variable and have some
sort of impact on the results; threat to internal validity - Consent
EX
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How to decrease confounding factors Ans: Randomizing the
assignment makes the treatment and control group approximately
the same with respect to all variables except for the explanatory
variable (treatment) and decreases the influence of confounding
factors
Placebo Effect Ans: the phenomenon in which the expectations of
the participants in a study can influence their behavior
Double-Blind Study Ans: An experiment in which neither the
participant nor the researcher knows whether the participant has
received the treatment or the placebo
What does a double-blind study alleviate? Ans: Possible bias in
diagnosis
To identify the explanatory variable in a pair of variables, identify
which of the two is suspected of affecting the other? Ans:
Explanatory variable — might affect — response variable
Generally, data in observational studies are collected only — while
experiment require the primary explanatory variable in a study —
for each subject by the researchers Ans: - by monitoring what
occurs
- be assigned
Making casual conclusions based on experiments is often
resonable. However, making the same casual convulsion based on
observational data can be treacherous and is not recommended.
Thus, observational studies are generally only sufficient... Ans: to
show associations
Casual Relationship in Stats Ans: Observational Studies: Don't do
it!!
© 2025 All rights reserved
STT Exam 1 Questions and Correct Answers
Explanatory variable Ans: - The variable that is manipulated by
researchers
- The variable that is thought to cause a different in an outcome
Response Variable Ans: - The variable that is observed by
researchers
- The variable that 'answers' the research question
In the early 1950's there was limited evidence that a vaccine
developed by Jonas Salk was both safe and effective, based on
small studies. A large-scale trial was needed to assess the
effectiveness of the vaccine. What is the explanatory and response
variable? Ans: Explanatory: If you get the vaccine or not
Response Variable: Immune response to polio/do you get it or not
Treatment Group Ans: The group of subjects in a study that
receives a treatment
Control Group Ans: A separate group of subjects in a study that
does not receive the treatment
Confounding Factors Ans: hidden variables that correlate in some
way with the independent or dependent variable and have some
sort of impact on the results; threat to internal validity - Consent
EX
© 2025 All rights reserved
, 2 | Page
How to decrease confounding factors Ans: Randomizing the
assignment makes the treatment and control group approximately
the same with respect to all variables except for the explanatory
variable (treatment) and decreases the influence of confounding
factors
Placebo Effect Ans: the phenomenon in which the expectations of
the participants in a study can influence their behavior
Double-Blind Study Ans: An experiment in which neither the
participant nor the researcher knows whether the participant has
received the treatment or the placebo
What does a double-blind study alleviate? Ans: Possible bias in
diagnosis
To identify the explanatory variable in a pair of variables, identify
which of the two is suspected of affecting the other? Ans:
Explanatory variable — might affect — response variable
Generally, data in observational studies are collected only — while
experiment require the primary explanatory variable in a study —
for each subject by the researchers Ans: - by monitoring what
occurs
- be assigned
Making casual conclusions based on experiments is often
resonable. However, making the same casual convulsion based on
observational data can be treacherous and is not recommended.
Thus, observational studies are generally only sufficient... Ans: to
show associations
Casual Relationship in Stats Ans: Observational Studies: Don't do
it!!
© 2025 All rights reserved
