Descriptive Biostatistics

Flashcards covering key concepts and terms from the lecture on descriptive biostatistics.

Descriptive Measures

Statistical tools used to summarize data by means of a single number.

Central Tendency

Statistical measures that define the center of a distribution, including mean, median, and mode.

Mean

The arithmetic average of a set of values; calculated as the sum of all observations divided by the number of observations.

Median

The middle value that separates a data set into two equal halves when ordered.

Mode

The most frequently occurring value in a data set.

Skewed Distribution

A distribution that is not symmetric; can be positively or negatively skewed.

Variance

A measure of dispersion that indicates how far a set of numbers is spread out from their mean.

Standard Deviation

The square root of the variance; measures the dispersion or spread of a data set.

Coefficient of Variation (CV)

A standardized measure of dispersion expressed as a percentage of the mean, useful for comparing variability between data sets.

Percentiles

Values that divide a data set into 100 equal parts, indicating the rank of data points.

Interquartile Range (IQR)

The range of the middle 50% of the data; calculated as Q3 - Q1.

Outlier

A data point that is significantly different from other observations, often lying outside the overall pattern of distribution.

Kurtosis

A statistical measure that describes the shape of a distribution's tails in relation to its peakness.

Frequency Distribution

A summary of how often each value occurs in a data set.

Histogram

A graphical representation showing the distribution of numerical data using bars.

Frequency Polygon

A line graph that connects the midpoints of each class interval to visualize frequency distribution.

Stem-and-Leaf Display

A method for organizing quantitative data in a way that preserves the original data while providing an overview of its distribution.

Box-and-Whisker Plot

A visual representation that summarizes data using the median, quartiles, and extremes.