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Example of Computing Pearson's r
To compute Pearson's manually, start by transforming the raw scores of two quantitative variables into scores. For example, consider an variable with a mean of and a standard deviation of , and a variable with a mean of and a standard deviation of . If an individual's score is (a score of ) and their score is (a score of ), their cross-product is . Another individual might have an score of () and a score of (), resulting in a cross-product of . By taking the mean of these cross-products for the entire sample, we arrive at the value for Pearson's . In this example, the mean of the cross-products is , indicating a positive relationship.
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Research Methods in Psychology - 4th American Edition @ KPU
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Example of Computing Pearson's r
Arrange the steps for calculating Pearson's r using the computational formula in the correct order.
In the computational formula for Pearson's (), how does the calculation distinguish between a positive and a negative relationship between two psychology variables?
In a study analyzing the relationship between 'Stress levels' and 'Sleep quality,' a psychology researcher uses the computational formula for Pearson's . Match each component of the formula with its specific analytical role in processing this data.
A researcher concludes that the initial step of transforming raw scores into -scores is optional when using the computational formula for Pearson's () and that using the original raw scores will yield the same correlation coefficient. This researcher's conclusion is correct.
According to its computational formula, Pearson's is defined as the mean of the ____.
According to the computational formula for Pearson's (), the correlation coefficient represents the total sum of all participants' -score cross-products, which causes the value of to grow larger as the sample size () increases.
A psychology researcher investigating the relationship between 'Social Media Use' and 'Subjective Well-being' in a sample of 25 participants () calculates that the sum of the -score cross-products () equals -12.5. Applying the formula , the Pearson's correlation coefficient for this data is _____.
A psychology student collects data on sleep hours () and cognitive performance test scores () for a sample of students. To apply the computational formula for Pearson's (), match each of the following mathematical terms to its corresponding role or representation in this study.
By analyzing the mathematical structure of the Pearson's formula (), a researcher can determine that dividing the sum of the standardized cross-products by the sample size () calculates the _____ of all these cross-products.
A research assistant proposes a protocol to calculate Pearson's from raw data. Evaluate the logical and mathematical requirements of the computational formula () and arrange the steps in the correct chronological order to successfully compute the coefficient.
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Arrange the steps for manually computing Pearson's r in the correct order.
When manually computing Pearson’s , what is indicated when an individual has a positive cross-product of -scores (such as )?
A researcher is manually computing Pearson’s for a study on stress (Variable : Mean = , = ) and sleep quality (Variable : Mean = , = ). Match each participant's set of raw scores to the specific -score cross-product they contribute to the final calculation.
In the manual calculation of Pearson's , a participant with -scores of on both variables provides a larger positive contribution to the final correlation coefficient than a participant with -scores of on both variables.
Suppose you are designing a dataset for a research methods lab to demonstrate a Pearson's of exactly with a sample size of participants. You have already determined the cross-products of the -scores for the first three participants to be , , and . To achieve your intended outcome, what specific value must you 'assign' as the cross-product for the fourth participant?
When manually computing Pearson's , the cross-products are calculated by multiplying the raw scores of the two variables together for each individual.
A researcher manually computing Pearson's stops after summing the cross-products of the scores for a sample. To critique this approach, one would argue that the researcher has not yet accounted for sample size and must still calculate the _____ of the cross-products to reach a standardized evaluation of the relationship.
A researcher studying daily exercise minutes (Variable : , ) and mood ratings (Variable : , ) is manually computing Pearson's . Match each participant's z-score description to the correct cross-product value.
When manually computing Pearson's , the reason raw scores must be converted to scores before cross-products are computed is that variables measured on different _____ would otherwise produce cross-products that reflect measurement artifacts rather than genuine co-variation.
A research methods student is peer-reviewing a classmate's manual computation of Pearson's . Arrange the following evaluation steps in the most logical sequence to systematically verify and judge the result before accepting it.
Explain the step-by-step process of manually computing Pearson's from the raw scores of two quantitative variables, including how individual score transformations lead to the final correlation coefficient.
Describe what the positive cross-product () indicates about the first participant's scores relative to the group means, and explain what the final mean of the cross-products () reveals about the overall relationship between sleep hours and alertness.
Given a participant with a score of on variable (mean = , standard deviation = ) and a score of on variable (mean = , standard deviation = ), calculate their individual scores and compute their resulting cross-product.