Chapter 2: Data Organization and Visualization Flashcards

Vocabulary flashcards based on Chapter 2 lecture notes covering data organization, frequency distributions, and statistical graphs.

Raw data

Data collected in its original form.

Frequency distribution

The organization of raw data in table form using classes and frequencies.

Class

A quantitative or qualitative category into which each raw data value is placed.

Frequency

The number of data values contained in a specific class.

Categorical frequency distribution

A distribution used for data that can be placed into specific categories, such as nominal or ordinal level data.

Grouped frequency distribution

A distribution used when the range of data is large and the data is quantitative.

Lower-class limit

The smallest possible data value in a class.

Upper-class limit

The largest possible data value in a class.

Class width

The value found by subtracting the lower-class limit of one class from the lower-class limit of the next class.

Class midpoint

The value obtained by adding the lower and upper boundaries or limits of a class and dividing by two.

Rules for Classes in Grouped Frequency Distributions

Five rules stating that classes must be 5 to 20 in number, mutually exclusive, continuous, exhaustive, and equal in length.

Cumulative frequency distribution

A distribution that shows the number of data values less than or equal to a specific value, usually the upper boundary.

Histogram

A graph that displays data by using vertical bars of various heights to represent the frequencies of the classes.

Frequency polygon

A graph that displays data by using lines that connect points plotted for the frequencies at the class midpoints.

Ogive

A graph that represents the cumulative frequencies for the classes in a frequency distribution.

Relative frequency graph

A graph created using proportions instead of frequencies, used when the proportion of data values in a class is more important than the actual count.

Bar chart

A chart that represents data by using vertical or horizontal bars whose heights or lengths represent the frequency of the data.

Pareto chart

A chart used to represent a frequency distribution for a categorical variable with frequencies displayed by vertical bars arranged in order from highest to lowest.

Time series graph

A graph that represents data that occur over a specific period of time.

Pie chart

A circle that is divided into sections or wedges according to the percentage of frequencies in each category of the distribution.

Dot plot

A statistical graph in which each data value is plotted as a point above the horizontal axis.

Stem and leaf plot

A data plot that uses part of a data value as the stem and part as the leaf to form groups or classes, retaining actual data while displaying it in graphic form.