Chapter 12: Quantitative Skills and Biostatistics

Bar graph

A graph that uses rectangular bars to represent data and compare values.

Pie graph

A graph that uses a circle divided into sectors to represent data as fractions of a whole.

Histogram

A graph that uses bars to represent the frequency of data within intervals.

Line graph

A graph that uses points connected by lines to show the trend of data over time or other continuous variables.

Box-and-whisker plot

A graph that displays the distribution of data by showing the median, quartiles, and outliers.

Scatterplot

A graph that displays the relationship between two variables by plotting their values as points on a coordinate plane.

Title

A descriptive heading that tells the viewer what the graph represents.

Measured axes

The lines that represent the values of the variables being graphed.

Labels and units

The text that explains what the values on the axes represent and in what units they are measured.

Index marks

The tick marks on the axes that show the scale of the graph.

Frame or perimeter

The boundary that encloses the graph and separates it from the rest of the page.

Data points

The individual values that are plotted on the graph to represent the data being displayed.

Count data

Data generated by counting the number of items that fit into a category.

Normal distribution

A type of data that fits a normal curve, usually for a large sample.

Sample size

The number of members of the population that are included in the study.

Mean

The average of the sample.

Outliers

Data points that are significantly different from other data points in a sample.

Nonparametric data

Data that often includes large outliers and do not fit a normal distribution.

Hypothesis

A prediction of what the outcome of the experiment will be.

Independent variable

The factor that is changed between the different groups in the experiment.

Dependent variable

The data that is measured during the experiment.

Constants (Controlled variables)

The things that are kept the same during the experiment.

Control group

Any group that is needed so you can compare the results of the experiment.

Statistical significance

The trustworthiness of the results and the certainty you have in your conclusions.

Lipids

A diverse group of biomolecules that includes fats, oils, waxes, and steroids, and are insoluble in water.

Phospholipids

A type of lipid molecule that forms the structural basis of cell membranes, consisting of a hydrophilic head and hydrophobic tails.

Cholesterol

A type of lipid molecule that is essential for cell membrane structure and function, and is also a precursor for the synthesis of steroid hormones.

Count data

Data generated by counting the number of items that fit into a category.

Normal distribution

A type of probability distribution where most of the data falls within a range close to the mean, forming a bell-shaped curve.

Hypothesis

A prediction of what the outcome of an experiment will be.