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Example of Restriction of Range: Age and Hip Hop Music
The statistical relationship between age and the enjoyment of hip hop music provides a clear example of how restriction of range can mislead researchers. Across the general population, there may be a strong negative correlation (e.g., ) between these variables. However, if data is collected exclusively from a restricted age group—such as 18- to 24-year-olds—the relationship appears artificially weak, dropping to a Pearson's of 0. This demonstrates the importance of sampling a wide range of values to accurately capture overall trends and avoid obscured results.

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Research Methods in Psychology - 4th American Edition @ KPU
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Example of Restriction of Range: Age and Hip Hop Music
Which of the following best describes the statistical issue known as 'restriction of range'?
A psychologist investigates the relationship between anxiety levels and test performance but recruits only participants whose anxiety scores fall within a narrow, moderate range. If a strong negative correlation between anxiety and test performance exists in the broader population, the psychologist's restricted sample is likely to produce a weaker correlation coefficient than what would be observed using a more representative sample.
A researcher is investigating various relationships in a population. Match each study's sampling strategy with the most likely impact it will have on the measured strength of the relationship compared to the true population relationship.
An educational psychologist is studying the relationship between 'reading speed' and 'comprehension scores.' In the general population, this relationship is strong. Arrange the following research scenarios in order based on the magnitude of the correlation they would likely reveal, from the lowest (closest to zero) to the highest.
You are designing a research protocol to investigate the relationship between 'conscientiousness' (a personality trait) and 'academic success' in a university setting. To construct a study that avoids the statistical issue of restriction of range, which of the following recruitment strategies should you propose?
In psychological research, the statistical issue of restriction of range occurs when a researcher's sample includes a wider variety of scores than are present in the actual population.
Match each term related to data variability with the statement that best explains its relationship to the strength of an observed correlation.
A researcher concludes that 'intelligence does not predict job performance' based on a study of a highly selective group of NASA engineers where the correlation was only . To evaluate the validity of this conclusion, a critic must recognize that the results are likely misleading because the sample creates a statistical issue known as _____ of range.
A research team is examining the correlation between age and hip-hop music preference. Knowing that the general population ages span from childhood to old age, they choose to collect data only from individuals aged 18 to 24. In doing so, their study will suffer from a statistical limitation that causes the observed correlation coefficient to appear misleadingly _____ compared to the actual relationship in the population.
Evaluate the following research sampling strategies for a correlational study on the relationship between age and hip-hop music preference. Order the strategies from the one that will produce the most misleadingly weak correlation (due to the most severe restriction of range) to the one that will produce the most accurate representation of the population's correlation coefficient (least restriction of range).
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When studying the relationship between age and enjoyment of hip hop music, what happens to the observed correlation if data is collected exclusively from a narrow age group, such as 18- to 24-year-olds?
True or False: In the study of age and hip-hop enjoyment, the correlation coefficient drops from -0.77 to zero when the sample is restricted to 18- to 24-year-olds because there is no longer enough variation in the age variable to reveal the broader trend.
A researcher is investigating how age relates to the enjoyment of hip hop music. Based on the provided scatterplots and the principle of range restriction, match each sampling scenario or concept with its corresponding statistical outcome.
Examine the scatterplots provided in the image. Arrange the following steps in the correct logical sequence to explain why the strong correlation between age and hip-hop enjoyment disappears in Plot (b) compared to Plot (a).
A researcher is developing a protocol to study how chronological age predicts various psychological preferences. To construct a data collection framework that avoids the specific statistical distortion shown in the provided scatterplots, where a strong population relationship () disappears in a narrow subgroup, which of the following sampling designs should be developed?
In the provided example, the Pearson's for the relationship between age and hip hop music enjoyment in the restricted age group ( to years) is reported as .
Based on the provided scatterplots illustrating the relationship between age and hip-hop enjoyment, match each sampling condition or statistical result with the statement that best explains its role in understanding range restriction.
A researcher collected data exclusively from - to -year-olds to study the relationship between age and hip hop enjoyment and found , concluding the two variables are unrelated. A critic argues this conclusion is invalid for the general population because the sample suffers from _____ of range, which obscures the true negative relationship () that emerges when participants across the full age spectrum are included.
In the age-and-hip-hop-music example, restricting data collection to participants aged 18 to 24 causes the Pearson's to drop from to because the narrow age band eliminates nearly all _____ in the age variable, making it impossible for the computed correlation to reflect the true population trend.
A psychology student reads a published study claiming that age does not predict hip hop music enjoyment () because the data were collected only from 18- to 24-year-olds. Order the following steps from first (1) to last (5) to properly evaluate whether the researcher's 'no relationship' conclusion is justified given the possibility of restriction of range.
Based on the provided example of range restriction, identify the Pearson's value representing the correlation between age and hip hop music enjoyment across the general population, the Pearson's value when the sample is restricted to - to -year-olds, and explain the general methodological recommendation derived from these findings.
Diagnose the statistical and design error in the researcher's study. Explain why her conclusion is misleading by referencing the correlation values expected across both the restricted group and the general population, and explain how she can correct her study's design.
If a research team is studying the relationship between age and hip hop music enjoyment but restricts their sample exclusively to people aged to , apply the principle of range restriction to predict what their calculated Pearson's will be and describe what they must do to obtain a correlation that reflects the true population trend of .
Based on the scatterplot showing the relationship between age and hip hop enjoyment, what is the observed correlation () within the restricted range of 18- to 24-year-olds (the shaded region) compared to the correlation across the entire sampled age range?
In a hypothetical study on the relationship between age and the enjoyment of hip hop music, researchers find different outcomes depending on how they sample their participants. Match each sampling approach or statistical concept to its corresponding outcome or description in this study.
An instructor wants to demonstrate the phenomenon of restriction of range using the relationship between age and hip hop music enjoyment. Arrange the steps of the demonstration in the correct order to illustrate how limiting the range of a predictor variable obscures a strong population correlation.
In a study examining the relationship between age and hip hop music enjoyment, a researcher restricts their sample to participants aged 18 to 24 and observes a Pearson's . Based on the provided scatterplot, the researcher can validly conclude that age does not predict hip hop enjoyment across the broader population, as the subgroup's correlation reflects the true absence of a general trend.
Refer to the provided scatterplot depicting the relationship between age and the enjoyment of hip hop music. A researcher evaluates only the data within the shaded region (representing 18- to 24-year-olds) and concludes that there is no relationship between age and hip hop enjoyment (). This conclusion is scientifically invalid because limiting the sample to this narrow age range represents a restriction of range, which causes the researcher to ________ the true strength of the negative correlation () present in the broader population.
In the textbook example of restriction of range, what is the nature of the correlation between age and hip hop music enjoyment across the general population?
In the example of age and hip hop enjoyment, restricting the sample to 18- to 24-year-olds reduces the variability of the age variable, which makes the observed correlation appear artificially weaker (approaching ) compared to the strong negative correlation () found in the general population.
A team of psychologists is designing a study to replicate the negative relationship between age and the enjoyment of hip hop music (where the general population correlation is ). To avoid an artificially weakened correlation of approximately due to restriction of range, which sampling strategy should they apply?
Examine the provided scatterplot, which illustrates the relationship between age and the enjoyment of hip hop music across different samples. Match each analytical sample-selection scenario with the correct description of its statistical effect on variance and the resulting Pearson's .
A journal reviewer is evaluating a manuscript where the author investigated the correlation between age and hip hop music enjoyment. The author sampled only college students aged 18 to 24, observed a Pearson's , and concluded: 'Age is not a statistically or practically meaningful predictor of hip hop music enjoyment.' Referencing the provided scatterplot, which of the following is the most methodologically sound evaluation of the author's conclusion?