Data, Accuracy and Precision

Scott Linneman
Western Washington University
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Initial Publication Date: April 30, 2008 | Reviewed: November 3, 2013


This first lab exercise requires lower-division geomorph students to generate and compare three topographic data sets for a small feature on campus.

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First exercise in lower-division geomorphology course.

Skills and concepts that students must have mastered

Basic spreadsheet operations.

How the activity is situated in the course

First group exercise.


Content/concepts goals for this activity

The overall objective of this lab is to help students develop a critical mind about gathering and evaluating data. This sort of approach is vital to doing well in this class, and in any science. More specifically, the objectives are to learn:
1. how to use three different tools (methods) to collect quantitative position data about a landscape: a level and tape; a GPS (global positioning system); and a total station.
2. how to compile these data on a spreadsheet, and then plot them as a topographic map or surface using computer software.
3. how to evaluate the quality (accuracy and precision) of those data by comparing the two maps to what you know is actually out there.
4. finally, give an assessment of the benefits and limitations of each method for collecting data.

Higher order thinking skills goals for this activity

Evaluating quantitative data.

Other skills goals for this activity

Using different surveying methods;
Using data analysis software (Excel & Surfer);
Writing brief reports;

Description of the activity/assignment

In Jigsaw format, groups of 3 students divide up and each collects topographic data for a small landform using a different technique (tape and level; handheld GPS; Total Station). When they re-group they compare data quantity and quality using spreadsheets and a mapping program. They write a group report comparing the strengths and weaknesses of the three methods.
Designed for a geomorphology course
Addresses student fear of quantitative aspect and/or inadequate quantitative skills
Addresses student misconceptions

Determining whether students have met the goals

Their report for this lab consists of a short (< 1 typed page) comparative description of the accuracy, precision and efficiency of three methods. They may include as many supporting tables and figures as needed, so long as they are labeled, numbers and well-organized. Reports are graded using the "Measurement Lab Report Grading Rubric."

More information about assessment tools and techniques.

Teaching materials and tips

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