PSY 291 EXAM 1 STUDY GUIDE QUESTIONS WITH
CORRECT ANSWERS
Inferential vs. Descriptive Statistics - CORRECT ANSWER-✔✔✅- Inferential Statistics: techniques that
allow us to study samples and then make generalizations about the populations from which they were
selected. Involves mathematical procedures that allow psychologists to make inferences about
collected data.
- Descriptive Statistics: statistical procedures used to summarize, organize, and simplify data. Used to
describe basic features of the data in the study.
Relationship between: Sample, Population, Statistic, and Parameter - CORRECT ANSWER-✔✔✅-
Sample: is a set of individuals selected from a population, usually intended to represent a population
in a research study.
> The 30 boys studied
- Population: is the set of all the individuals of interest in a particular study.
> Adolescent boys who take medication for depression
- Statistic: a value, usually numerical, that describes a sample. It is usually derived from
measurements of individuals in the sample.
- Parameter: is a value, usually numerical, that describes a population. It is usually derives from
measurements of the individuals in a population.
Sampling Error - CORRECT ANSWER-✔✔✅The natural occurring discrepancy, or error, that exists
between a sample statistic and the corresponding population parameter
Given description of an experiment, identify independent and dependent variables - CORRECT
ANSWER-✔✔✅- Independent Variables: is the variable that is manipulated by the researcher. A
variable that stands alone and is not influenced by other variables.
> How the pen is held, humorous or not, signs
- Dependent Variable: is the variable that is observed to assess the effect of the treatment. Depends
on other factors.
> Rating of the cartoon, # of sentences remembered, use of the stairs
, Experimental vs. Observational Studies - CORRECT ANSWER-✔✔✅- Experimental Study: one variable
is being manipulated which another variable is being observed and measured.
> The amount of caffeine, observe the amount of activity of the children in the playground
- Observational Study: researcher is only observing nothing is being manipulated
> Records the level of activity on the playground
Classify variables as discrete or continuous - CORRECT ANSWER-✔✔✅- Discrete Variables: consist of
separate, indivisible categories. No values can exist between 2 neighboring categories
> # of colds in a year
- Continuous variables: there are an infinite number of possible values between any two recorded
values.
> Age, height, temperature, severity of a cold
Identify measurement scale: nominal, ordinal, interval and ratio - CORRECT ANSWER-✔✔✅-
Nominal: attributes are only names, one is not better than the other.
> Brand of sneakers, male given #1 and female given #2
- Ordinal: attributes can be ordered. Rank observations in terms of size or measurement. Distances
between each of the scales may not be the same.
> Race: who came 1st, 2nd, and 3rd, GPA can go from a 4.0 to a 3.99 and the next student may have a
3.21
- Interval: distance is meaningful. Consists of ordered categories that are all intervals of the same
exact size.
> 0 degrees F means something
- Ratio: contains absolute 0 therefore 0 means the absence of something
> 0 students means that there were none present
Confounding variables and ethical problems with human subjects - CORRECT ANSWER-✔✔✅- When
a variable influences the results
> If one group watches Boonie and Clyde during that hour there behavior will change
- Wording of the question can introduce bias
> poll conducted in Germany
- Method of questioning can introduce bias
CORRECT ANSWERS
Inferential vs. Descriptive Statistics - CORRECT ANSWER-✔✔✅- Inferential Statistics: techniques that
allow us to study samples and then make generalizations about the populations from which they were
selected. Involves mathematical procedures that allow psychologists to make inferences about
collected data.
- Descriptive Statistics: statistical procedures used to summarize, organize, and simplify data. Used to
describe basic features of the data in the study.
Relationship between: Sample, Population, Statistic, and Parameter - CORRECT ANSWER-✔✔✅-
Sample: is a set of individuals selected from a population, usually intended to represent a population
in a research study.
> The 30 boys studied
- Population: is the set of all the individuals of interest in a particular study.
> Adolescent boys who take medication for depression
- Statistic: a value, usually numerical, that describes a sample. It is usually derived from
measurements of individuals in the sample.
- Parameter: is a value, usually numerical, that describes a population. It is usually derives from
measurements of the individuals in a population.
Sampling Error - CORRECT ANSWER-✔✔✅The natural occurring discrepancy, or error, that exists
between a sample statistic and the corresponding population parameter
Given description of an experiment, identify independent and dependent variables - CORRECT
ANSWER-✔✔✅- Independent Variables: is the variable that is manipulated by the researcher. A
variable that stands alone and is not influenced by other variables.
> How the pen is held, humorous or not, signs
- Dependent Variable: is the variable that is observed to assess the effect of the treatment. Depends
on other factors.
> Rating of the cartoon, # of sentences remembered, use of the stairs
, Experimental vs. Observational Studies - CORRECT ANSWER-✔✔✅- Experimental Study: one variable
is being manipulated which another variable is being observed and measured.
> The amount of caffeine, observe the amount of activity of the children in the playground
- Observational Study: researcher is only observing nothing is being manipulated
> Records the level of activity on the playground
Classify variables as discrete or continuous - CORRECT ANSWER-✔✔✅- Discrete Variables: consist of
separate, indivisible categories. No values can exist between 2 neighboring categories
> # of colds in a year
- Continuous variables: there are an infinite number of possible values between any two recorded
values.
> Age, height, temperature, severity of a cold
Identify measurement scale: nominal, ordinal, interval and ratio - CORRECT ANSWER-✔✔✅-
Nominal: attributes are only names, one is not better than the other.
> Brand of sneakers, male given #1 and female given #2
- Ordinal: attributes can be ordered. Rank observations in terms of size or measurement. Distances
between each of the scales may not be the same.
> Race: who came 1st, 2nd, and 3rd, GPA can go from a 4.0 to a 3.99 and the next student may have a
3.21
- Interval: distance is meaningful. Consists of ordered categories that are all intervals of the same
exact size.
> 0 degrees F means something
- Ratio: contains absolute 0 therefore 0 means the absence of something
> 0 students means that there were none present
Confounding variables and ethical problems with human subjects - CORRECT ANSWER-✔✔✅- When
a variable influences the results
> If one group watches Boonie and Clyde during that hour there behavior will change
- Wording of the question can introduce bias
> poll conducted in Germany
- Method of questioning can introduce bias
