Basic Statistics for the Behavioral Sciences - Chapter Three

These flashcards cover key terms and definitions from Chapter Three of Basic Statistics, focusing on frequency distributions and percentiles.

Frequency

The number of times a specific score occurs in a dataset, symbolized by the letter $f$.

Distribution

An organized set of data that illustrates how scores are spread throughout the dataset.

Sample Size ($N$)

The total number of scores recorded in a complete dataset.

Cumulative Frequency ($cf$)

The sum of frequencies for all scores that fall at or below a specific score.

Percentile

The percentage of scores within a dataset that are at or below a certain value.

Relative Frequency ($rel.\ f$)

The proportion of time a specific score occurs, representing its frequency relative to the total number of scores.

Simple Frequency Distribution

A tabular summary displaying the frequency for each individual score in the data.

Histogram

A bar graph for interval or ratio data with a small range of scores, where the bars are placed side-by-side so they touch.

Frequency Polygon

A line graph used for a large range of scores, created by connecting data points with straight lines.

Normal Distribution

A symmetrical, bell-shaped curve where the frequencies descend toward the ends but never reach a true zero.

Skewed Distribution

An asymmetrical distribution characterized by one pronounced tail, which can be either positive or negative.

Positive Skew

A type of distribution where the tail extends toward the higher (more positive) scores on the x-axis.

Negative Skew

A type of distribution where the tail extends toward the lower (more negative) scores on the x-axis.

Symmetrical Distribution

A distribution where both halves are mirror images of each other; examples include normal, bimodal, and rectangular distributions.

Bimodal Distribution

A symmetrical distribution that features two distinct peaks or 'humps'.

Rectangular Distribution

A symmetrical distribution shaped like a rectangle, indicating that all scores have the same frequency and there are no tails.

Grouped Distribution

A distribution that organizes data into small ranges or 'groups' to report frequency, relative frequency, or cumulative frequency totals.

Tail of a Distribution

The tapered end of a frequency distribution curve where scores become less frequent.