Chapter 2: Frequency Distributions

Question 1

Raw Score

Answer 1

A data point that has not yet been transformed or analyzed

Question 2

Frequency Distribution

Answer 2

Describes the pattern of a set of numbers by displaying a count or proportion for each possible value of a variable

Question 3

Frequency Table

Answer 3

A visual depiction of data that shows how often each value occurred, that is scores were at each value; values are listed in a column, and the numbers of individuals with scores at that value are listed in the second column

Question 4

Grouped Frequency Table

Answer 4

Visual depiction of data that reports the frequencies within a given interval rather than the frequencies for a specific value

Question 5

Steps to generate a standard grouped frequency table

Answer 5

1. Find the highest and lowest scores in your frequency distribution
2. Get the full range of data
3. Determine the number of intervals and the best interval size
4. Figure out the number that will be the bottom of the lowest interval
5. Finish the table by listing the intervals from highest to lowest and then counting the numbers of scores in each

Question 6

Histogram

Answer 6

Looks like a bar graph but is typically used to depict scale data with the values of the variable on the x-axis and the frequencies on the y axis

Question 7

Steps to construct a histogram from a frequency

Answer 7

1. Draw the x-axis and label it with the variable of interest and the full range of values for this variable
2. Draw the y-axis, label it Frequency and include the full range of frequencies for this variable
3. Draw a bar for each value, centering the bar around that value on the x-axis and drawing the bar as high as the frequency for that value as represented on the y-axis

Question 8

Steps to construct a histogram from a grouped frequency table

Answer 8

1. Determine the midpoint for every interval
2. Draw the x-axis and label it with the variable of interest and the midpoints for each interval of values on this variable
3. Draw the y-axis and label it frequency and include the full range of frequencies for this variable
4. Draw a bar for each midpoint, centering the bar on that midpoint on the x-axis and drawing the bar as high as the frequency for that interval as represented on the y-axis

Question 9

Frequency Polygon

Answer 9

A line graph with the x-axis representing values (or midpoints of intervals) and the y-axis representing frequencies; a dot is placed at the frequency for each value (or midpoint), and the dots are connected

Question 10

Normal Distribution

Answer 10

Specific frequency distribution that is a bell-shaped, symmetric, unimordal curve

Question 11

Skewed distribution

Answer 11

Distributions in which one of the tails of the distribution is pulled away from the center; lopsided, off-center, or simply nonsymmetric

Question 12

Positively Skewed

Answer 12

The tail of the distribution extends to the right, in a positive direction

Question 13

Floor effect

Answer 13

A situation in which a constraint prevents a variable from taking values below a certain point

Question 14

Negatively Skewed

Answer 14

Have a distribution with a tail that extends to the left, in a negative direction

Question 15

Ceiling effect

Answer 15

A situation in which a constraint prevents a variable from taking on values above a given number

Question 16

Stem-and-Leaf Plot

Answer 16

A graph that displays all the data points of a variable (or of two levels of a variable) both numerically and visually; looks like a histogram if turned on its side

Question 17

Steps to create a Stem-and-Leaf Plot

Answer 17

1. Create the stem

2. Add the leaves