Nature of Geographic Information
Posted: December 9, 2016 | Updated: February 9, 2021
Author: David DiBiase, Penn State
The purpose of this text is to promote understanding of the Geographic Information Science and Technology enterprise (GIS&T, also known as "geospatial").
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Nature of Geographic Information by David DiBiase, Penn State is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.
3.7 / 5
Q: The text covers all areas and ideas of the subject appropriately and provides an effective index and/or glossary
There are some topical areas where the text feels imbalanced. Some topics like databases in Chapter 1 and LiDAR in Chapter 8 are barely mentioned while surveying has large dedicated sections. There is also some imbalance in figure placement. Parts of Chapter 8, for example, are deserts of text with no oases of illustrations. Overall, most topics that I would expect to see are covered in some detail.
Comprehensiveness Rating: 4 out of 5
Q: Content is accurate, error-free and unbiased
I did not find any major errors in the content. I would rate the accuracy as fair, insofar as accuracy encompasses currency of information. Most of the examples discussed in the text are obsolete, out-of-date, and/or have been replaced by other software, websites, web pages, and applications. For example, Adobe Flash applications are referenced throughout, but Adobe no longer support Adobe Flash Player as of December 31, 2020. I did not try all the links in the text, but some of the websites that I am familiar with have changed their layout and organization, making the screenshots inaccurate. Much of the textbook requires updating especially some of the “Try this” sections that require exploring a website. Below are some minor comments for each chapter.
- 1.7 attribute is not defined and features are never mentioned
- P7 not a “list of attributes”, but a list of codes stored in an attribute named FIPSQ
- First 9 pages have no illustrations
- 1.8 GIS history is incomplete
- 1.9 “Encoded as alphanumeric symbols”, data encoding has a specific meaning (data types). Also, alphanumeric symbols is ambiguous. Encode should be defined. Basic geometries should be explicitly defined here (point, line, polygon). “Vector data model”... here at last should define data model. “Every grid cell ... is encoded with an attribute”... no, it is encoded with a value; one raster = one attribute.
- Image captions are not always evident. Figure numbers would help, especially for the print version.
- 1.12 and 1.14 seem superfluous to the chapter objectives. Talk of labor standards, bodies of knowledge and competency models do not meet any of the chapter objectives nor is it related to Data and Information.
- Section 1.19 is labelled as 19
- 2.1 summarizes ch 1 about “generalization” and “scales without defining such
- SPC, NAD, UTM not defined
- 2.5 map is missing
- Try this before 2.12 flash application is missing resource
- 2.12 point 5 should be “N or E”
- 2.31 I think “georegister” is never defined or discussed in the chapter
- 3.3 missing leading quotation “ for constitution quote
- Generally the chapter is very American centric, and also outdated
- Terminology related to the census data is very specific to the US and not particularly generalized to other jurisdictions
- Weird formatting in 3.4 pg 94
- Objective 2 is ambiguous “levels of measurement of attribute data”
- Objective 1: “metadata” is not defined prior in the text
- 3.10 unnecessary to discuss suitability modelling here
- 3.17 “centroid” is not defined prior in the text
- Is shapefile defined are this point?
- Shapefiles do not support topology, so why use them as an example in this chapter? Does the census bureau still use shapefiles for this purpose?
- What is a shapefile extract? Not defined but used repeatedly
- Mostly references the 2010 census, which is outdated
- 4.4 accuracy stuff is not germane to the chapter learning objectives
- “Geometric accuracy” or “positional accuracy”
- 4.5 Shapefile Primitives defines a point with “double-precision”, but data types have not yet been introduced
- 4.8 geocoding screenshots of websites are quite outdated
- 5.4 “data is” should be “data are”
- 5.6 “elevations are relative to NAVD 88” will be replaced by NATRF2022 in 2022. Maybe worth mentioning the change/update. Also, prior to now, the difference between horizontal and vertical datums has not been discussed, defined.
- 5.6 “base error” and “line error” are not defined
- 6.7 should be labelled 5.7
- “8. Measuring Distances” should be labelled 5.8
- 5.13 “HEIGHTS” could benefit from more explanation of geoid, orthometric height and geodetic height. These are important concepts. Very weakly related back to digital data in GIS. This reads more field methods. Diagrams would be helpful.
- 5.14 Galileo is built and now Beidou plus India is on track to create its own
- 5.21 Try this: the Trimble planning software can be accessed through an online web application instead of downloading software. Suggest revising this activity so that Mac users can do it.
- 5.24 Try this: maybe update the 6 MPB file download times.
- Image showing relief displacement is not very helpful. Suggest instead showing a visualization of terrain.
- Consider adding discussion or section for radial displacement of features, which is important for interpretation and tall features
- Surprised there was no discussion of air photo interpretation: color, tone, texture, context, shadows, etc considering their importance to all derived national data
- The use of anaglyphs throughout is really nice
- Summary section ends up summarizing some things that were not actually discussed in the chapter: loss of jobs
- 7.4 figure showing vector versus raster elevation representations is a bit confusing. The raster should show a grid with the digital numbers in each cell. As currently depicted, it gives the impression that a raster is a grid of point samples, which is not accurate.
- 7.15 unnecessary and out of place
- Routing, linear referencing systems, and topology glanced over
- Contour tracing demonstration seems really useful and a great link between the data and cartographic representations of elevation data
- I wonder if many of the datasets and website links in the chapter are still valid?
- Consider introducing and defining: reflection, absorption, transmission, scattering at the outset. Some figures show transmission or reflection without discussing these fundamental concepts.
- 8.7 should discuss temporal resolution
- 8.10 temporal resolution is mentioned here, but not defined previously
- 8.11 IFOV and swath width could benefit from an illustration
- False color imagery is glossed over and not clearly explained
- EarthExplorer needs updating as they have reorganized the data collections with OLS
- 8.15 could benefit from illustrations, for example for sun-synchronous orbits
- Cost of Landsat scenes is irrelevant now that everything is free
- 8.18 qualities of air photo interpretation should be mentioned in the earlier chapter on air photos. The objective of this chapter is to cover satellite imagery.
- 8.25 new topics are introduced in the summary including the definition of hyperspectral data
- Lidar remote sensing is absent from the chapter, though satellite-based lidar has been available since 2003 (ICESAT and GLAS)
- [ ] The remote sensing chapter overall is very comprehensive. There are few learning objectives outlined at the beginning, and the chapter could easily address those learning objectives in fewer sub sections. Suggest breaking the chapter in two: satellite remote sensing systems and derived information.
- 8.4 figure should have y axis labelled as energy emitted from the Sun
Content Accuracy Rating: 4 out of 5
Q: Content is up-to-date, but not in a way that will quickly make the text obsolete within a short period of time. The text is written and/or arranged in such a way that necessary updates will be relatively easy and straightforward to implement
Nearly all of the examples discussed are out-of-date. This is probably due to the fact that the text was written many years ago and has not been updated. However, there are so many examples in the text that reference specific dates as of the writing of the text. For example, the U.S. census data, newer satellite launches, and more recent advances in GNSS. See my comments in the accuracy section for specific cases. This text really needs to be updated to remain relevant and interesting.
Relevance Rating: 3 out of 5
Q: The text is written in lucid, accessible prose, and provides adequate context for any jargon/technical terminology used
I enjoyed the writing in the textbook. I appreciated the story telling used to convey the technical concepts. Jargon was usually avoided, however, I noted some instances where a term or acronym was used without being defined prior, which can lead to confusion.
Clarity Rating: 4 out of 5
Q: The text is internally consistent in terms of terminology and framework
The text followed an expected framework of setting learning objectives at the outset, providing “TRY THISl activities, and concluding with a summary section. Sometimes, new concepts were introduced in the summary section, which I found unfair to the reader, because it did not provide a meaningful opportunity to engage with some of those topics.
Consistency Rating: 4 out of 5
Q: The text is easily and readily divisible into smaller reading sections that can be assigned at different points within the course (i.e., enormous blocks of text without subheadings should be avoided). The text should not be overly self-referential, and should be easily reorganized and realigned with various subunits of a course without presenting much disruption to the reader.
The text has good modularity. I never felt like a section was too long. However, Chapter 8 was too long and could easily have been divided into two different chapters focusing on remote sensing systems/platforms and their qualities and another chapter on applications like classification, time series, interpretation, false colour imagery, etc. The biggest issue that I found with the modularity of the text is how heavy the dependence is on American examples. I could never assign most chapters of this text to my Canadian classroom because the examples are completely irrelevant. Most of the text is built around various American programs and the fundamental concepts of GIS are lost if you are not familiar with the American context or working with the described U.S. data.
Modularity Rating: 4 out of 5
Q: The topics in the text are presented in a logical, clear fashion
The organization of the text is very good. Reading the chapters sequentially made a lot of sense, and the concepts seemed to build and accumulate. Some topics seemed fragmented, however, like aerial photography, elements of which appear and are discussed across several different chapters. This can make it difficult to adopt the text as a reference text.
Organization Rating: 4 out of 5
Q: The text is free of significant interface issues, including navigation problems, distortion of images/charts, and any other display features that may distract or confuse the reader
I reviewed the print version of the text. Most images were of sufficient quality and printed well. There was at least one figure that I found was missing. In the print version, there was some weird formatting were some figures would take up half a page with no wrapped text. I think these were mostly in Chapter 8, but it made it difficult to read at times and I found myself flipping through a bunch of pages of figures only to come to a wall of text. Text could be better integrated around the figures in the print version.
Interface Rating: 3 out of 5
Q: The text contains no grammatical errors
I have pointed out some grammatical and spelling errors in my other comments about accuracy. Overall, only a few sections with these types of errors.
Grammar Rating: 4 out of 5
Q: The text is not culturally insensitive or offensive in any way. It should make use of examples that are inclusive of a variety of races, ethnicities, and backgrounds
I never felt offended by the language of the text. There were several references to women who were quoted, but not much more. The text could benefit from discussion of power and inequality in geographic information, which I would argue is part of its “nature”. Maps lie, people have biases, and geographic information is quite powerful. GIS are, after all, human enterprises. I think there is significant work to be done in this area, particularly if the author is inclined to update the text at some point.
Cultural Relevance Rating: 3 out of 5
Q: Are there any other comments you would like to make about this book, for example, its appropriateness in a Canadian context or specific updates you think need to be made?
I would recommend this text to my American colleagues, but I would not use it to teach GIS in my Canadian classroom. The examples are just not relevant to my classroom. That said, I think the text is brilliantly written around the American context. I really appreciate how well the core themes of GIS are effortlessly interweaved into practical examples, as a good GIS text should achieve. Future practitioners may do well to understand these basic principles and some US programs that are consumed around the world (e.g., Landsat). However, the text does not lend itself well to be easily understood by learners outside the US context. Due to the organization of the content and themes around US programs, standards, and government websites (e.g., USGS, TIGER, FGDC, NSDI), the text performs poorly as a reference for a quick refresh or introduction to many topics.