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These posts explore fundamental concepts of soil geography, ranging from the philosophy of science to particular methods in soil informatics. Often the motivation of a post is based on disambiguation of terms/concepts that have been vague or suffer from multiple meanings. I revisit these fundamental concepts to improve understanding and to “think out loud” on issues that need discussion to increase clarity. I welcome your comments as part of the conversation.

Oracles and Science: The Trouble with Predictions

13 October 2015 23:55

We all want to know the future, but what is the best way to make predictions? Assuming we don’t have a crystal ball, we have to find patterns in the available information and make our best, informed guess. This is what scientists do.

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The Real Benefits of Digital Soil Mapping

5 July 2015 13:16

Traditional soil mapping methods are not as bad as they are sometimes made out to be, which can cause us to misunderstand the advancements we’ve made with digital soil mapping. In many cases, the most significant difference between traditional and digital soil maps is the quality and amount of data available to make the map. This is where digital soil mapping truly shines, because it would be practically impossible to utilize all of the data we have now for mapping soil using traditional methods.

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Types of Measurement Error

30 May 2015 14:46

We always want to avoid error, but it is a fact of life. At the foundation of analysis and modelling, we rely on measurements. Because errors in measurements are inescapable, the important question is how much does the error affect the result? I start the conversation by explaining what measurement error is, including its component parts, and what we can do to minimize its effect.

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CLORPT: Spatial Association in Soil Geography

24 April 2015 21:18

From as early as 500 BCE, humans have recognized that some things vary together in space. This is essentially correlation, but the spatial aspect sometimes adds a special twist. The first scientific application of spatial association to soil mapping that we know about was by E.W. Hilgard. He observed that knowledge of the geology and type of vegetation were useful indicators for predicting soil type. Today in digital soil mapping, we still utilize these concepts, but because we use much more quantitative variables, we typically describe this method as spatial regression, or a little more specifically, environmental correlation.

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The Value of Soil: A Spatial Perspective

25 March 2015 10:30

Soil scientists like to remind everyone that “soil is not dirt,” but what is the difference? One way to answer that question is to identify where it is. Is it somewhere that it is useful, fulfilling its role as supporting life and improving environmental quality? Or has it been moved to a place where it actually causes problems, while the place it came from is also handicapped by the loss of functional ability?

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Colluvium vs Alluvium

23 February 2015 13:44

Among various Earth scientists, I’ve encountered slightly different definitions for colluvium and, by association, alluvium. The definitions for colluvium and alluvium are interdependent because their respective definitions are partially based on distinguishing one from the other. In other words, a set of characteristics is being used to split into two classes something that could be defined as one thing. Nonetheless, their distinction is important for communicating key characteristics, geomorphic setting, and inferred processes.

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Accuracy vs Precision

18 January 2015 16:06

Scientists often measure and predict things. Therefore, we need ways to describe how much we know, how close a number is to reality, and how likely we are to get the same number again. The terms accuracy and precision are generally used to describe these things, but there can be some ambiguity. This post explains the difference between the two and explores the different aspects of precision’s multiple meanings.

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Types of Scale

8 December 2014 19:13

When you read the phrases “large scale” or “small scale,” do you know what they mean? Sometimes “large scale” is describing a large area and sometimes it is describing a small area, depending on if the author was thinking about process scale or cartographic scale. This is a problem for communication. In this post I describe the different types of scale that geographers recognize, which will hopefully encourage others to be specific when they are discussing scale.

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Fundamentals of Spatial Prediction

16 November 2014 11:50

In the process of creating a map, geographers often have to engage in the activity of spatial prediction. Although there are many tools we use to accomplish this task, they generally boil down to the use of one or two fundamental concepts: spatial association and spatial autocorrelation.

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The Cycle of Science

17 August 2014 15:58

Although the terms regularly used today are different, in practice modern science uses induction and deduction in a cycle. Data is collected, which is often used to build models. Where weaknesses in these models are found, more data is collected and different model designs are tested in order to make a better model.

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