Questions and Answers
What is the population for the study on texting habits of high school students?
All high school students in the United States.
What is the sample for the study on texting habits of high school students?
The group of 100 students who were measured in the study.
The average number that the researcher calculated is an example of a ______.
statistic
Define the terms population and sample.
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What is the population for the study on caffeine's effect on memory?
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What is the sample for the caffeine study?
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The group that received caffeinated coffee is a(n) ______.
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The group that received decaffeinated coffee is a(n) ______.
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The sample contains ______ participants.
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The averages calculated after the memory test is a ______.
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What are the two major categories of statistical methods?
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What is the average IQ of everyone in the United States?
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The value of 105 is a ______.
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The value of 100 is a ______.
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Describe the scales of measurement for age, income, number of dependents, and social security number.
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What are the upper and lower real limits of a height measured to the nearest whole inch?
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What additional information is obtained from measurements on an ordinal scale compared to measurements on a nominal scale?
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What is incorrect about saying the coffee is twice as warm as the temperature outside?
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What is the dependent variable in a study comparing learning performance with different study mediums?
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The dependent variable is ______.
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The scale of measurement used for the dependent variable is ______.
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Did this study use experimental or nonexperimental methods?
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Identify the independent and dependent variables in this study.
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Identify the independent and dependent variables in the study by Ford and Torok (2008).
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What scale of measurement is used for the independent variable in the study by Ford and Torok (2008)?
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What is the value of EX for the scores: 4, 2, 6, 3?
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What is the value of (EX)^2 for the scores: 4, 2, 6, 3?
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What is the value of EX-3 for the scores: 4, 2, 6, 3?
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What is the value of E(X-3) for the scores: 4, 2, 6, 3?
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What is the value of E(X-4)^2 for the scores: -1, -3, 6, -4, 0?
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What is the value of (EX)^2 for the scores: -1, -3, 6, -4, 0?
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What is the value of EX^2 for the scores: -1, -3, 6, -4, 0?
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What is the value of E(X+3) for the scores: -1, -3, 6, -4, 0?
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What is the value of EX for the scores: 3, 1, -2, -4, 2?
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What is the value of EY for the scores: 1, 5, 2, 2, 4?
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What is the value of E(X+Y) for the scores: (3,1), (1,5), (-2,2), (-4,2), (2,4)?
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What is the value of EXY for the scores: (3,2), (1,6), (5,0), (2,5), (0,6)?
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What is the value of EXEY for the scores: (5,1), (3,3), (0,5), (-3,7), (-5,9)?
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Express the calculation: Multiply scores X and Y and then add each product.
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Express the calculation: Sum the scores X and sum the scores Y and then multiply the sums.
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Express the calculation: Subtract X from Y and sum the differences.
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Express the calculation: Sum the X scores.
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What is the value of EX^2 for the scores: 6, 1, 4, 5, 2?
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What is the value of (EX)^2 for the scores: 6, 1, 4, 5, 2?
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What is the value of E(X-3) for the scores: 6, 1, 4, 5, 2?
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What is the value of E(X-3)^2 for the scores: 6, 1, 4, 5, 2?
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What is the value of n for the scores: 3, 2, 5, 0, 1, 6?
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Study Notes
Research Methodology and Key Concepts
- Research aims to examine social phenomena by selecting a sample that represents the entire population, which refers to a larger group, e.g., all high school students in the United States.
- The sample's statistical representation leads to conclusions about the population based on measurable data, such as the average number of texts sent daily.
- A statistic describes data from a sample, while a parameter describes the entire population.
Types of Statistical Methods
- Descriptive statistics summarize and organize data, making it manageable and easier to interpret, often using tables or graphs.
- Inferential statistics enable researchers to generalize findings from a sample to a larger population and analyze relationships.
Variables and Measurement Scales
- Four scales of measurement are identified: nominal, ordinal, interval, and ratio.
- A variable's scale determines the type of data collected, with examples such as age as a continuous ratio variable, while social security numbers are nominal and discrete.
- Continuous variables can take on any value within a range, while discrete variables have defined, separate values.
Experimental vs. Nonexperimental Studies
- Experimental studies manipulate an independent variable to observe changes in a dependent variable, allowing for cause-and-effect conclusions.
- Nonexperimental studies observe associations between variables without manipulation, making it difficult to establish causation.
Examples of Research Outcomes
- A study comparing drinking habits between Canadian and American college students reveals cultural and environmental differences without experimental manipulation.
- Research indicating that afternoon exam performance is superior to morning performance may be influenced by sampling error, leading to generalized conclusions rather than definitive outcomes.
Additional Insights into Research Design
- Random assignment enhances experimental validity, ensuring that groups are comparable.
- Control over extraneous variables is crucial in experimental designs for isolating the effect of the independent variable on the dependent variable.
Limitations of Measurement
- Measurement error can skew results. For example, an individual's height reported as a whole number contains imprecision due to rounding.
- Real limits define the range of possible true values around a rounded measurement, providing context to data accuracy.
Statistical Interpretations and Results
- Descriptive and inferential statistics yield different types of information, with the former providing simple summaries and the latter offering broader implications for hypothesis testing.
- Understanding how to distinguish between statistically significant findings and those due to chance is foundational to the scientific research process.### Card 22
- For the scores X: 4, 2, 6, 3, the expected value EX equals 15.
- Squaring the expected value: (EX)^2 results in 225.
- Subtracting 3 from EX gives EX - 3 = 12.
- E(X-3) equals the sum of the scores after subtracting 3 from each: = (-1) + (3) + (0) = 3.
Card 23
- For scores X: 3, 5, 4, 2, 1:
- nE(X-1) requires finding the expected value adjusted by 1.
- EX - 3^2 involves subtracting 9 from the expected value.
- E(X-2)/n requires calculating the mean of scores adjusted by 2.
- E(X-4)^2 evaluates the squared value after subtracting 4.
Card 24
- For scores X: -1, -3, 6, -4, 0:
- E(X-4)^2 results in 158.
- E(X)^2 calculates to 4.
- EX^2 sums to 62.
- E(X + 3) produces 13.
Card 25
- For participants' scores:
- EX totals to 0 when summing values (3, 1, -2, -4, 2).
- EY totals to 14 when summing values (1, 5, 2, 2, 4).
- E(X+Y) computes the combined score total, equalling 14.
- EXY is found by calculating the products of corresponding X and Y scores leading to a total of 4.
Card 26
- For participant scores:
- EXY equals 2 by multiplying corresponding scores and summing.
- EXEY totals 56 through the calculation of expected value products.
- EY sums up to 7 through the Y scores.
- n (the number of observations) is 4.
Card 27
- Summation notation for various calculations:
- Multiplying X and Y followed by summation is represented as Σ(X * Y).
- Sums of X and Y squared can be noted as (ΣX)(ΣY).
- Subtracting and summing results in Σ(Y - X).
- The total sum of X is represented as ΣX.
Card 28
- For score calculations:
- Adding scores and squaring results in (ΣX)^2.
- Squaring individual scores and summing is noted as Σ(X^2).
- Subtracting 2 points from each and summing is E(X - 2).
- Squaring results after subtracting 1 yields E(X - 1)^2.
Card 29
- For scores X: 6, 1, 4, 5, 2:
- EX^2 represents the summation of squares.
- (EX)^2 is the square of the expected value.
- E(X-3) computes the expected value after adjusting by 3.
- E(X-3)^2 is the square of the expected value after adjustment.
Card 30
- For participant scores:
- nEX^2 results in 195.
- (EY)^2 calculates to 361.
- EXY totals to 22 through respective products.
- EXEY sums up to 209 through expected values.
Card 31
- For participant scores:
- Find nEX^2 for squared expected values.
- Calculate (EY)^2 for Y values squared.
- Determine EXY through product sum of corresponding scores.
- Calculate EXEY for combined expected value results.
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Description
This quiz focuses on key concepts from Chapter One of research methods, specifically regarding populations and samples. It includes questions on understanding research design and applying statistical measures. Test your knowledge and prepare for further studies.
