Question 1

To test for age differences in intelligence,at the beginning of the school year a researcher gave the same mathematics test to groups of children who were 8,10,12,and 14 years of age.This procedure best illustrates a

Accepted Answer

The procedure described in the question is a classic example of a cross-sectional study, where data is collected from groups of individuals of different ages at the same point in time. The researcher is interested in comparing the performance of children at different age groups on the same test, and the study design allows for a quick and efficient way to do so. A scatterplot is a visual representation of the relationship between two variables and is not applicable in this context. A longitudinal study would involve collecting data from the same group of individuals over an extended period, which is not the case here. Standard deviation is a statistical measure of the spread of the data, which is not relevant in this question.

Question 2

Research in which people of different ages are compared with one another at one time is a

Accepted Answer

A cross-sectional study involves comparing different groups of people at one point in time. This is in contrast to a longitudinal study, which follows the same group of people over a period of time. A scatterplot is a graphical representation of the relationship between two variables, and regression toward the mean refers to the tendency for extreme scores on one measurement to be closer to the mean on a subsequent measurement.

Question 3

Statistical significance refers to whether research

Accepted Answer

Statistical significance refers to the likelihood that the findings of the research are not due to chance variations. It does not indicate causality, random assignment, or support of previous findings.

Question 4

Research in which the same group is tested and retested over a period of years is a

Accepted Answer

A longitudinal study involves testing the same group of individuals over a period of time, often years. This allows researchers to track changes and development within the group and make more accurate conclusions about the effects of different factors on their behavior or characteristics. Cross-sectional studies, on the other hand, compare different groups at one point in time, while scatterplots and regression toward the mean are statistical analyses rather than research methods.

Question 5

As the size of a sample ________ ,the size of the standard deviation is most likely to ________ .

Accepted Answer

As the size of a sample increases, the size of the standard deviation is most likely to decrease. This is because as the sample size increases, the estimate of the mean becomes more precise, and therefore the variability around the mean (i.e. standard deviation) is reduced.

Question 6

With use of cross-sectional studies to assess the effect of aging on adults' mental abilities,it is especially important to consider the impact of ________ between generations.

Accepted Answer

Educational differences can be a significant factor influencing the results of cross-sectional studies, as education levels have risen across generations. This means that younger generations may have had more access to education and cultural experiences that could have an impact on their mental abilities compared to older generations who had less access to formal education. Therefore, it is important to control for educational differences when assessing the effect of aging on mental abilities in cross-sectional studies.

Question 7

To compare verbal intelligence at different age levels,researchers tested and retested a group of children from the time they were 2 until they reached the age of 20.The researchers were clearly conducting a

Accepted Answer

The researchers were following the same group of individuals over a long period of time, which is characteristic of a longitudinal study.

Question 8

An observed difference between two sample groups is more likely to be statistically significant if

Accepted Answer

The amount of variability in each of the sample groups is an important factor in determining statistical significance. If the variability is small, then any observed difference between the groups is more likely to be meaningful and statistically significant. This is because the smaller the variability, the easier it is to detect a difference between the two groups. Thus, choice C is the best answer. Choices A and B are incorrect because a small observed difference and small sample sizes would make it less likely to achieve statistical significance. Choice D is not necessarily true since significant differences can be observed between groups even if they are drawn from different populations.

Question 9

A random sample of females was observed to exhibit a lower average level of self-esteem than a random sample of males.To assess the likelihood that this observed difference reflects a real difference in the average self-esteem of the total population of males and females,you should

Accepted Answer

Conducting a test of statistical significance would be the most appropriate method for determining whether the observed difference in self-esteem levels between males and females is statistically significant. This would allow us to determine whether the difference is likely to be due to chance or if there is a meaningful difference between the populations of males and females in terms of self-esteem. The other options, such as constructing a scatterplot or plotting the distribution of self-esteem levels, may be useful for visualizing the data, but they do not directly address the question of statistical significance.

Quiz 15: Statistical Reasoning in Everyday Life