# Graphs

Quick links to other graphing pages: Basic graphing skills, Understanding trends, Interpolation/Extrapolation, Functions, Graph Significance, Graphing confusion

# Graphs

created by Jennifer M. Wenner, Geology Department, University of Wisconsin-Oshkosh

Graphing skills play an important role in many introductory geoscience courses. Students are expected to be able to plot data on x-y graphs, to estimate or approximate trends in data, to interpret trends in the context of geology. Sometimes graphs in geoscience textbooks are presented in formats that are foreign or confusing to students, even those who have had classical mathematics.

Because graphs and graphing concepts in introductory geoscience courses involve a variety of issues for both students and faculty, we present a number of pages designed to assist in the presentation of these skills. These pages address issues ranging from remedial skills to the geologic contexts in which we present these complex concepts.

## Basic graphing skills

Or, skills students probably learned in high school - This page discusses skills that faculty may (generally correctly) assume that students were taught while they were in high school.

The important concepts covered include:

• the definition of a graph,
• constructing meaningful plots
• plotting x-y data sets,
• describing plots/graphs
• reading and interpreting data from a graph.

or, important skills that introductory geoscience students may not have encountered in the past. There are a number of upper level skills that we may need to expand on before the students can complete exercises that demand the use of these mathematical concepts. These include:

• ### Trends

This page deals with visuallizing and approximating trends, including constructing a best-fit line, calculating slope and estimating correlation/covarience
• ### Interpolation/extrapolation

This page deals with the mathematics of trends. There is information about mathematical approximations of data sets, using known data points to understand the relationship of data points (interpolation) and the use of data and graphs as predictive tools (extrapolation).
• ### Functions

Mathematical functions play an important role in the quantitative understanding of the world around us. Geoscientists use functions to model the behaviors of natural functions. This page helps faculty teach about the importance of functions, the derivation of functions from data, as well as a discussion of derivation of data from functions. In addition a section is included about how we use functions in geology.
• ### technology

The use of technological advances continues to increase in the classroom. There are a number of technological tools that can be used to help students to understand graphing and the function of graphing. The links below can help with teaching students how to use these tools.

## Teaching the significance of graphs

This page helps faculty with teaching techniques that address models of the natural world, helping students to:
• make connections between natural world and mathematics
• recognize graphs as a means of visualizing volumes of data
• interpret graphs in a geologic context.

## Sources of (possible) student confusion in geology

This page addresses the things that geologists do with graphs that may confuse students who have learned and internalized the "rules" for graphing in mathematics. This includes:
• graphs that are "upside down" (increasing in the "negative" direction, e.g., geothermal gradient)
• extraneous or interpretive information included on the plot
• rotated plots in which the y-axis is the invariant axis (this is never done in mathematics).