Population Vs. Sample
A researcher is interested in the texting habits of high school students in the United States. The researcher selects a group of 100 students, measures the number of text messages that each individual sends each day, and calculates the average number for the group.
Identify the population in this study.
The entire set of high school students in the United States.
A statistic is which of the following? Check all that apply.
A. Always a dependent variable
B. A characteristic of a sample
C. A characteristic of a population
D. Always an independent variable
B. A characteristic of a sample
Descriptive statistics are generally used for which of the following? Choose all that apply:
A. To describe dependent variables only
B. To make general conclusions about populations using sample data
C. To simplify and summarize data
D. To describe independent variables only
C. To simplify and summarize data
X
3
2
4
2
∑X =
= 11
What additional information is obtained from measurements on an ordinal scale compared to measurements on a nominal scale?
A. Direction of difference (greater or less) between two measurements
B. Magnitude of difference between two measurements
C. Comparison of the magnitudes of two measurements (such as one being twice as large as the other)
Direction of difference (greater or less) between two measurements
A researcher is interested in the texting habits of high school students in the United States. The researcher selects a group of 100 students, measures the number of text messages that each individual sends each day, and calculates the average number for the group.
Identify the sample in this study.
The 100 students who were measured in the study
A parameter is which of the following? Check all that apply.
A. Always an independent variable
B. A characteristic of a population
C. Always a dependent variable
D. A characteristic of a sample
B. A characteristic of a population
Inferential statistics are generally used for which of the following? Check all that apply.
A. To simplify and summarize data
B. To describe independent variables only
C. To make general conclusions about populations using sample data
D. To describe dependent variables only
C. To make general conclusions about populations using sample data
X
3
2
4
2
∑X²=
= 33
Guéguen and Jacob (2012) asked female restaurant wait staff to wear different colored T-shirts on different days for a six-week period and recorded the tips left by male customers. The results show that male customers gave significantly bigger tips when the wait persons were wearing red.
What scale of measurement is used for the independent variable?
Remember NOIR (Nominal, Ordinal, Interval, Ratio)
Double points if you can explain why! :D
Nominal
Color of the T-shirt (red versus not red) is measured on a nominal scale.
A researcher is interested in the texting habits of high school students in the United States. The researcher selects a group of 100 students, measures the number of text messages that each individual sends each day, and calculates the average number for the group.
The average number that the researcher calculated is an example of a _____________.
Statistic
FILL IN THE BLANKS
Sampling error is the naturally occurring discrepancy between a _____________ and the corresponding ____________.
Sample Parameter Population Statistic
Sample Statistic Population Parameter
1) Sample Statistic
2) Population Parameter
Honesty is a hypothetical construct rather than a concrete variable because it is:
A. An indirect method for measuring and defining an attribute
B. A characteristic that can be observed directly
C. An external attribute or characteristic
D. An internal attribute or characteristic that cannot be observed directly
D. An internal attribute or characteristic that cannot be observed directly
Honesty is a hypothetical construct, because it is an internal attribute or characteristic that cannot be observed directly.
X
1
2
4
1
3
∑X² =
= 31
What additional information is obtained from measurements on a ratio scale compared to measurements on an interval scale?
A. Magnitude of difference between two measurements
B. Direction of difference (greater or less) between two measurements
C. Comparison of the magnitudes of two measurements (such as one being twice as large as the other)
C. Comparison of the magnitudes of two measurements (such as one being twice as large as the other)
A ratio scale provides information about the ratio of two measurements, which allows comparisons such as “twice as much.”
FILL IN THE BLANKS - WORDS CAN BE REPEATED ;)
Research beings with a question about the ___________. However, the ____________ is usually ______________________. Therefore, the individuals in the __________ are the actual participants, and the results from them are then ___________________.
Population Sample
Statistic Independent Variable
Too large for every individual to participate in the research study
Generalized to the population
Ignored
Too small to obtain meaningful results to apply to all individuals
1) Population
2) Population
3) Too large for every individual to participate in the research study
4) Sample
5) Generalized to the population
Define a Parameter
Numbers that summarize data for an entire population.
Describe how honesty might be measured and defined using an operational definition. Check all that apply.
A. By giving participants a multiple choice questionnaire on which the answers indicate how they behave or feel in situations for which honesty might have an influence
B. By asking a series of specific questions and measuring participants’ physiological responses using a polygraph
C. By asking participants to write an essay describing what part honesty plays in their lives
D. By asking participants to describe an incident in which they felt they were being particularly honest
E. By asking participants to rank their fellow participants in terms of honesty
A & B
Honesty could be operationally defined by identifying and observing participants’ external behaviors associated with being honest, such as the physiological responses to questions measured by a polygraph (“lie detector”). Or, participants could be given a questionnaire asking how they behave or feel in situations for which honesty might have an influence.
X
1
2
4
1
3
∑(X + 1)² =
= 58
Explanation
∑(X + 1)² =
(1 + 1)² + (2 + 1)² + (4 + 1)² + (1 + 1)² + (3 + 1)² =
2² + 3² + 5² + 2² + 4² =
4 + 9 + 25 + 4 + 16 = 58
Identify the scale of measurement that should be used and identify whether the variable is continuous or discrete.
Number of dependents = _________ & __________
Social security number = _________ & __________
Number of dependents = Ratio & Discrete
Family size consists of whole-number categories with no intermediate values.
Social security number = Nominal & Discrete
Social security numbers are essentially names that are coded as 9-digit numbers. There are no intermediate values between two consecutive social security numbers.
Define a Statistic
Numbers that summarize the data from a sample.
X
-2
-2
7
-3
-1
∑(X + 3) =
= 14
∑(X + 3) =
(-2 + 3) + (-2 + 3) + (7 + 3) + (-3 + 3) + (-1 + 3) =
(1) + (1) + (10) + (0) + (2) = 14
Identify the scale of measurement that should be used and identify whether the variable is continuous or discrete.
Age = ___________ & _____________
Annual Income = __________ & _____________
Age = Ratio & Continuous
Although people usually report whole-number years, the variable is the amount of time, and time is infinitely divisible.
Annual Income = Ratio & Discrete
Income is determined by units of currency. For US dollars, the smallest unit is the penny, and there are no intermediate values between 1 cent and 2 cents.