PSC 41 UNIT 5 TOPIC BASED QUESTIONS WITH
ANSWERS!!
What questions should you ask when assessing statistical validity?
Answers :Has the research identified a real relationship? (how strong is it, what is
the margin of error) Were the proper inferences made?
What are descriptive statistics, and what is used to describe it?
Answers :Calculations that describe the main aspects of sample data. Use central
tendency and measure of spread.
When do you use the different forms of central tendency?
Answers :Categorical/Nominal: Mode
Categorical+ordered/ordinal: Mode, Median
Cont./interval or ratio: Mode, Median, Mean
If the data is skewed which form of central tendency should you use?
Answers :Median
What measure of dispersion can usually be used, and what type of central tendency
can it only be used with?
Answers :Standard Deviation, only can be used with means
What are the problems with comparing raw scores?
Answers :You can't tell where the score is relative to the average. You can't
directly compare raw scores from different scales
What is the standardized score form used for comparing?
, Answers :Z-scores
What are Z-scores?
Answers :0=average
+#=above the mean
-#=below the mean
each number represents a standard deviation
When describing the effects in a factorial design what should you be looking for?
Answers :What is the main effect of each predictor variable?
What is the relationship between the predictor variables (additive vs interaction)
What is an additive relationship between predictor variables?
Answers :The effects of the predictor variables change together in a linear fashion
(effect of one on the outcome does not depend on the other)
On a graph the relationships will be parallel
What is an interaction relationship between predictor variables?
Answers :The level of one predictor variable modifies the effects of the other
predictor variable.
On a graph the relationships are not parallel
What are inferential statistics? What is used to describe it?
Answers :Calculations that allow inferences about a population to be drawn from a
sample. Take into account noise/error (are these variables related, are they taken
from the same population or the same)
ANSWERS!!
What questions should you ask when assessing statistical validity?
Answers :Has the research identified a real relationship? (how strong is it, what is
the margin of error) Were the proper inferences made?
What are descriptive statistics, and what is used to describe it?
Answers :Calculations that describe the main aspects of sample data. Use central
tendency and measure of spread.
When do you use the different forms of central tendency?
Answers :Categorical/Nominal: Mode
Categorical+ordered/ordinal: Mode, Median
Cont./interval or ratio: Mode, Median, Mean
If the data is skewed which form of central tendency should you use?
Answers :Median
What measure of dispersion can usually be used, and what type of central tendency
can it only be used with?
Answers :Standard Deviation, only can be used with means
What are the problems with comparing raw scores?
Answers :You can't tell where the score is relative to the average. You can't
directly compare raw scores from different scales
What is the standardized score form used for comparing?
, Answers :Z-scores
What are Z-scores?
Answers :0=average
+#=above the mean
-#=below the mean
each number represents a standard deviation
When describing the effects in a factorial design what should you be looking for?
Answers :What is the main effect of each predictor variable?
What is the relationship between the predictor variables (additive vs interaction)
What is an additive relationship between predictor variables?
Answers :The effects of the predictor variables change together in a linear fashion
(effect of one on the outcome does not depend on the other)
On a graph the relationships will be parallel
What is an interaction relationship between predictor variables?
Answers :The level of one predictor variable modifies the effects of the other
predictor variable.
On a graph the relationships are not parallel
What are inferential statistics? What is used to describe it?
Answers :Calculations that allow inferences about a population to be drawn from a
sample. Take into account noise/error (are these variables related, are they taken
from the same population or the same)
