Quantitative Research Techniques + Statistics –
Peregrine|
A company developed a smartphone whose average lifetime is unknown. In order to
estimate the average, 200 smartphones are randomly selected from a large production line
and tested; their average is found to be 5 years. The 200 smartphones represent: - -a
sample
Significance level - -Measures the reliability of a statistical inference
inferential statistics - -Process of using sample statistics (mathematics) to draw
conclusions about population parameters
mutually exclusive - -Events that cannot occur at the same time.
sampling error - -the difference between the results of random samples taken at the
same time
non-sampling error - -occurs when the sample data are incorrectly collected,
recorded, or analyzed. Three types of errors: data acquisition errors, non-response errors
(or bias), selection bias
Design of a good survey components - -short survey, short/simple questions, start
with demographic questions, ues dichtomous (yes-no) and multiple choice
Direct observation - -example: counts backpacks on campus for a day
stratified random sample - -a sample from selected subgroups of the target
population in which everyone in those subgroups has an equal chance of being included in
the research
example: The manager of a customer service division wants to know if the customers in the
past 12 months are satisfied with their purchase of CD's. There are four types of CD's.
Joint Probability - -the probability of the intersection of two events
, Quantitative Research Techniques + Statistics –
Peregrine|
Union of two events - -The union of events A and B is the event containing all sample
points that are in A or B or both
Marginal Probability - -the probability of a single event without consideration of any
other event
Conditional Probability - -the likelihood that a target behavior will occur in a given
circumstance
Bayes Law - -calculates posterior probability
exhaustive - -including everything possible; very thorough or complete
Central Limit Theorem (CLT) - -The name of the theorem stating that the sampling
distribution of a statistic (e.g. x ) is approximately normal whenever the sample is large and
random. Allows us to draw conclusions about the population based on strictly sample
data.
sampling distribution of the mean - -1. the sampling distribution of the mean has a
different mean from the original population
2. the standard deviation of the sampling distribution of the mean is referred to as the
standard deviation
3. if the original population is not normally distributed, the sampling of the mean will be
normal
Suppose you are given 3 numbers that relate to the number of people in a sample. The
three numbers are 10, 20 and 30. If the standard deviation is 10, the standard error equals -
-5.77
Peregrine|
A company developed a smartphone whose average lifetime is unknown. In order to
estimate the average, 200 smartphones are randomly selected from a large production line
and tested; their average is found to be 5 years. The 200 smartphones represent: - -a
sample
Significance level - -Measures the reliability of a statistical inference
inferential statistics - -Process of using sample statistics (mathematics) to draw
conclusions about population parameters
mutually exclusive - -Events that cannot occur at the same time.
sampling error - -the difference between the results of random samples taken at the
same time
non-sampling error - -occurs when the sample data are incorrectly collected,
recorded, or analyzed. Three types of errors: data acquisition errors, non-response errors
(or bias), selection bias
Design of a good survey components - -short survey, short/simple questions, start
with demographic questions, ues dichtomous (yes-no) and multiple choice
Direct observation - -example: counts backpacks on campus for a day
stratified random sample - -a sample from selected subgroups of the target
population in which everyone in those subgroups has an equal chance of being included in
the research
example: The manager of a customer service division wants to know if the customers in the
past 12 months are satisfied with their purchase of CD's. There are four types of CD's.
Joint Probability - -the probability of the intersection of two events
, Quantitative Research Techniques + Statistics –
Peregrine|
Union of two events - -The union of events A and B is the event containing all sample
points that are in A or B or both
Marginal Probability - -the probability of a single event without consideration of any
other event
Conditional Probability - -the likelihood that a target behavior will occur in a given
circumstance
Bayes Law - -calculates posterior probability
exhaustive - -including everything possible; very thorough or complete
Central Limit Theorem (CLT) - -The name of the theorem stating that the sampling
distribution of a statistic (e.g. x ) is approximately normal whenever the sample is large and
random. Allows us to draw conclusions about the population based on strictly sample
data.
sampling distribution of the mean - -1. the sampling distribution of the mean has a
different mean from the original population
2. the standard deviation of the sampling distribution of the mean is referred to as the
standard deviation
3. if the original population is not normally distributed, the sampling of the mean will be
normal
Suppose you are given 3 numbers that relate to the number of people in a sample. The
three numbers are 10, 20 and 30. If the standard deviation is 10, the standard error equals -
-5.77
