Just How Faithful is Old Faithful? Finding Order in Random Behavior
Summary
In this Spreadsheets Across the Curriculum activity, students use NPS monitoring data to determine the frequency distribution (histogram) of eruption intervals of Old Faithful. The module stresses the utility of the monitoring data: Development of geothermal energy outside the park could affect the hydrothermal workings of the geyser, and so the data establish a baseline for the eruption interval at Old Faithful. In the process, the students work through material on the concept of probability, the construction of histograms, and the use of Excel functions such as MAX, MIN, COUNT, and COUNTIF. They also watch an animation showing how a geyser works. The QL intent of the module is to introduce Geology of National Parks students to the frequency concept of probability and to have them create a histogram.
This material is based upon work supported by the National Science Foundation under Grant Number NSF DUE0836566. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Learning Goals
Students will:
 See on a map the relation between Yellowstone's geyser basins and the Yellowstone caldera.
 See beforeandafter photos from Nevada of a geyser turned off by development of a geothermal power plant.
 Watch an animation adapted from the Yellowstone NP Web site showing how a geyser requires a heat source, water, earthquakes, and plumbing.
 Follow on a graph from GOSA (Geyser Observation and Study Association) how temperature varies vs. time through an eruption and thus see how one can monitor the precise time of a geyser eruption.
 Consider the difference between the classic definition of probability and the frequency definition of probability.
 Be instructed on how to load Excel's Analysis ToolPack Addin and build a histogram.
 Create a frequency histogram of eruption intervals at Old Faithful for 2008.
 Use the histogram to answer questions about the probability of eruptive intervals of various lengths.
In the process the students will:
 Learn that geysers are fragile. Learn how a geyser works and, therefore, why they are fragile.
 Be introduced to some of the how and why of the monitoring of thermal resources at Yellowstone.
 Gain experience with probability, histograms and frequency distributions.
Context for Use
This module is designed for potential use in the Geology of National Parks service course at USF. The course is offered as an online course every semester. It includes readings from Parks and Plates, weekly quizzes based on that textbook, and weekly student activities designed to align the course with the University's general education requirements. This module is intended to be one of those activities, with the specific goal of meeting the gened quantitative literacy dimension.
This module is one of four on Yellowstone NP, one of three on hydrothermal features, and one of two specifically on geysers. From least to most challenging, and most general to most specific, the order of the four modules is: (1) "Yellowstone! A National Park on a Hot Spot," (2) "A Percentage Stroll through Norris Basin," (3) this module, and (4) "Explore the Mean at Riverside Geyser." Much of the introductory material in this module is repeated in "Explore the Mean at Riverside Geyser."
Description and Teaching Materials
The module is a PowerPoint presentation with embedded spreadsheets. Click on the link below to download a copy of the module.

PowerPointSSACgnp.GB1198.TCJ1.2 (PowerPoint 6.4MB Jun1 13)
Optimal results are achieved with Microsoft Office 2007 or later; the module will function in earlier versions with slight cosmetic compromises. If the embedded spreadsheets are not visible, save the PowerPoint file to disk and open it from there.
The above PowerPoint presentation file is the student version of the module. It includes a template for students to use to complete the spreadsheet(s) and answer the endofmodule questions, and then turn in for grading.
An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher (vacher@usf.edu) by filling out and submitting the Instructor Module Request Form.
Teaching Notes and Tips
Assessment
There is a slide at the end of the presentation that contains endofmodule questions. The endofmodule questions can be used to examine student understanding and learning gains from the module. Pre/post test, pre/post test answer key, and answer key for endofmodule questions are at the end of the instructor version of the module.
References and Resources
Old Faithful
The Geyser Observation and Study Association (GOSA)
SNOTEL website
US National Park Service (NPS)