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A psychological researcher reports that a sample of participants completed a stress assessment, resulting in a mean score of and a standard deviation of . Explain what these specific descriptive statistics indicate about the scores of the participants in this sample.
Question: A psychological researcher reports that a sample of participants completed a stress assessment, resulting in a mean score of and a standard deviation of . Explain what these specific descriptive statistics indicate about the scores of the participants in this sample.
Sample answer: A mean of indicates that the average score in the sample is . A standard deviation of is a measure of dispersion indicating there is no spread or variation in the scores, meaning every single participant in the sample scored exactly .
Key points:
- The mean score of represents the typical or average score of the sample.
- A standard deviation of indicates that there is zero dispersion or spread in the dataset.
- Zero dispersion means that all individual scores in the sample are identical to the mean score of .
Rubric: The response is correct if it explains that the mean represents the average score of the sample () and that a standard deviation of (no dispersion) means there is no variation, concluding that all participants obtained the exact same score of .
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Research Methods in Psychology - 4th American Edition @ KPU
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Correlation Coefficient
Sample Statistic
Descriptive Statistics in Experimental Research
Descriptive Statistics in Non-Experimental Research
Inferential Statistics
Understanding Descriptive Statistics
Scatterplot
Measures of Central Tendency
Measures of Dispersion
Forms of Statistical Relationship
Mean
Standard Deviation
Bar Graph
Line Graph
What is the primary purpose of using descriptive statistics in psychological research?
Match each category of descriptive statistics with the specific goal it accomplishes when a researcher is summarizing their data.
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In a psychological study where a distribution of scores is highly skewed by a single extreme outlier, the mean is a more valid descriptive statistic than the median for evaluating the typical performance of the sample.
Measures of dispersion, such as the standard deviation and variance, are descriptive statistics used to describe the average scores within a research sample.
Tables in Research Reports
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A psychological researcher reports that a sample of participants completed a stress assessment, resulting in a mean score of and a standard deviation of . Explain what these specific descriptive statistics indicate about the scores of the participants in this sample.
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