The Scores

Our rating scores are based on 10 = THE perfect field guide.

Guess what?…No such field guide (yet) exists! There are a few guides that may rate a “10” in one or two categories, but the perfect guide is an illusive ideal that may never be attained.

Our ratings cover five areas that we feel are essential to all field guides:

  • Portability: how small and light-weight is it?
  • Quality: the accuracy and quality of the information provided.
  • Features: how many of essential features of a field/finding guide (book or app) does it provide. Note that in general book field guides tend to score lower on features.
  • Usability: how easy is it to use effectively. Books tend to score higher than apps in usability (except for books that require a lot of flipping around!)
  • Completeness: how comprehensive is the information provided for all of the species in the area covered?

The Criteria

How small and light-weight is it?

  • 10 = wearable
  • 9 = app or phone-sized booklet (roughly 3x5x0.4″ / 8 x13x1cm)
  • 7 = slim field guide (about 4.5×8.5×1″ or 12x19x2.5cm)
  • 5 = typical field guide (5.5x10x1.5 or 14x22x3cm
  • 3= large/heavy guide or desk reference
  • 1 = very large desk reference
  • 10 = essentially full coverage of the main age/sex and geographic variants of effectively all species including vagrants implied by the title with good illustrations, text, range maps, and representative sounds for all species covered (Note that almost no guides will meet this standard to earn a 10)
  • 8 = coverage of nearly all species, but with noticeable gaps, such as limited sounds, missing age/sex coverage for some species or cursory coverage of rarities
  • 6 = coverage for almost all expected species, most with good coverage of the range of age/sex and geographical variation but with serious gaps (e.g. sounds). A good guide, but serious users would need other resources to compliment this one
  • 4 = typical coverage for expected species and a range of the most important age/sex or geographical variants but far from full coverage; Usefulness of guide limited by these gaps.
  • 2 = serious gaps in coverage that severely hamper the utility of the guide.
“Features” measures the number of different and useful things you can do with the field guide.

10 = Provides all of the essential features of a high-quality field guide: Identify most individuals to species; study and improve identification skills; determine which species are likely to occur in a given location and habitat; figure out where to go find a given species. Other desirable features: record sightings / life list, both photos and illustrations, sounds (if applicable to group), species finding guide, detailed similar species text, natural history information, search by name, filter by ID attributes and filter by location.
8 = provides all of the essential features and most of the desirable features, or the features aren’t fully implemented;
6 = provides all of the essential features (except sound in the case of books) and some of the desired features;
4 = good overall, but missing some essential features; guide significantly limited by missing features;
1-2 = features limited enough to render the guide not useful for most users

“Quality” measures the accuracy of the information provided, including life-like, accurate illustrations; well-written text free of typos, erroneous information, or major errors of omission; maps that accurately reflect known ranges; sounds (if applicable) of high quality and labeled correctly, etc.

  • 10 = essentially error-free
  • 8 = few errors, but nothing that interferes with the usefulness of the work
  • 6 = errors or omissions that slightly interfere
  • 4 = errors are frequent and/or noticeable enough that they significantly interfere with the utility of the work
  • 1-2 perhaps good enough for some applications, but not adequate for the needs of most users.
“Usability” refers to how easy a book or app is to use effectively. Includes the intuitiveness of the interface and the ease of using (and learning to use) features.

  • 10 = Features all easy to use; Interface and all major features so obvious and intuitive that learning is almost instant for most users
  • 8 = Mostly easy to use with a good interface that is easy to learn but perhaps with a quirk or two. Most modern book field guides are 6 to 9 because they will immediately be intuitive to users.
  • 6 = a good interface that typical users can learn to navigate with just a little initial effort.
  • 4 = noticeable usability issues, such as with books that separate text from plates and require a lot of flipping around; or books that place the species in difficult-to-understand order; or books or apps with print that is too small for typical users to read.
  • 1-2 very difficult to use to the point where it severely limits the utility of the guide.

We’re Tough

The Perfect Field Guide Doesn’t Exist

There are some great field guides out there, but none are perfect.   We try to highlight the strengths and weaknesses of each guide, to help you choose the best guide for you. Our ratings our tough.  We believe “Perfection” is an an ideal and may be unattainable for many of the rating criteria.


Expert Reviews

By nature lovers, for nature lovers.

We’re a group of avid naturalists with extensive experience using field guides . Our goal is to give you the most insightful reviews based on our use and knowledge of each field guide.

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