Ap B

Question 1

Define descriptive statistics.

Answer 1

Statistics used to describe and summarize data collected in research.

Question 2

Define inferential statistics.

Answer 2

Statistics used to draw conclusions about research data.

Question 3

What is a frequency distribution?

Answer 3

A summary that shows the frequency of different scores or categories in a dataset.

Question 4

What is an ungrouped frequency distribution?

Answer 4

A count of the number of times each unique score occurs in a dataset.

Question 5

What is a grouped frequency distribution?

Answer 5

A count of the number of times scores fall into specific ranges or classes in a dataset.

Question 6

How can you identify the highest and lowest scores using a frequency distribution?

Answer 6

By observing the first and last entries in a sorted list of scores or by checking the frequencies in the distribution.

Question 7

What is a histogram?

Answer 7

A bar chart representing the frequency of specific data points in a dataset, often used for ungrouped frequency distributions.

Question 8

What is the benefit of using a grouped frequency distribution?

Answer 8

It simplifies the data by reducing the number of unique categories, making it easier to analyze larger datasets.

Question 9

What does a histogram’s x-axis represent?

Answer 9

The ordered listing of the various values or scores.

Question 10

What does a histogram’s y-axis represent?

Answer 10

The frequency of the scores.

Question 11

What is a frequency polygon?

Answer 11

A line graph depicting a grouped frequency distribution, created by connecting the midpoints of each class of data.

Question 12

How do you calculate midpoints for a frequency polygon?

Answer 12

The midpoint is calculated as the average of the upper and lower bounds of each class.

Question 13

What are measures of central tendency?

Answer 13

Numbers used to summarize data sets, such as the mean, median, and mode.

Question 14

What is the mean?

Answer 14

The average value in a data set, calculated by summing all values and dividing by the number of items.

Question 15

How do you calculate the median?

Answer 15

Order the data from smallest to largest and find the middle value; if even, take the average of the two middle values.

Question 16

What is the mode?

Answer 16

The most frequently occurring score or value in a data set.

Question 17

How is the range calculated?

Answer 17

The range is the difference between the largest and smallest values in a data set.

Question 18

What is variance?

Answer 18

A calculated indicator of how much values in a data set differ from the mean; the average of squared deviations from the mean.

Question 19

What is the standard deviation?

Answer 19

The square root of the variance, providing a measure of how much scores vary within a group in the same metric as the original data.

Question 20

What is a normal distribution?

Answer 20

A symmetrical, bell-shaped distribution where most scores cluster around the mean, with fewer scores at the extremes.

Question 21

What does the peak of a normal distribution represent?

Answer 21

The mean, median, and mode of the distribution, where most values are concentrated.

Question 22

What does it mean that a distribution is positively skewed?

Answer 22

Most values occur at the lower end of the scale, with a few high scores pulling the mean upward.

Question 23

What is a negatively skewed distribution?

Answer 23

A distribution where most values occur at the upper end of the scale, with a few low scores pulling the mean downward.

Question 24

What are measures of association?

Answer 24

Descriptive statistics that quantify and summarize the degree of relationship between variables.

Question 25

What is a random sample?

Answer 25

A sample in which every member of the population has an equal chance of being selected.

Question 26

What is the purpose of random assignment in experiments?

Answer 26

To ensure that any differences between experimental and control groups are evenly distributed, making the groups as similar as possible.

Question 27

What is hypothesis testing?

Answer 27

A statistical method to test a statement or claim about a population using sample data, focusing on experimental and control group differences.

Question 28

What does the null hypothesis assert?

Answer 28

That there is no difference between the average performance of individuals in one group compared to another.

Question 29

What does the alternative hypothesis propose?

Answer 29

That there is a difference between the average performance of individuals in one group compared to another.

Question 30

What is a sampling distribution?

Answer 30

The theoretical distribution of a sample statistic, such as the difference between two sample means from a population.

Question 31

What is an effect size?

Answer 31

A standardized measure that reflects the degree of relationship or size of the difference between two or more variables.

Question 32

What is Cohen’s d?

Answer 32

A common effect size measure that quantifies the standardized difference between two population means.