Answer: YOU make up the Challenge!

Diving in Fiji.  Huge numbers of colorful fish on the coral reef.

As usually happens, this turned out to be deeper and more interesting than I'd expected.  (That's one of the things I love about writing this blog--there's always something more to learn that holds my attention powerfully.)  

This week's Challenge was... 

2.  Can you create a Search Challenge that highlights the use of the  subject: operator in Google Books? 

Ideally, you'll write a Challenge that requires the use of a search in Google Books that needs the subject: + subject-heading method to be solvable.  

As you found out, this is actually a little tricky.  It's easy to write a simple question ("Is an ostrich's eye bigger than its brain?")  But it's harder to write a Challenge question that actually requires the use of a particular skill.  

In this case, the skill we're highlighting is "use of the subject: operator in Google Books."  

When I write the weekly Challenges, I try to make it so the Challenge can be solve ONLY with the skill (or data) under consideration.  And that's often the tricky part.  

So let's think about what the subject: operator does... Basically, it just limits or scopes the search to books that have that particular tag in the metadata.  

An example:  Suppose I want to find a book that talks about the color of reef fishes.  (I want to know the answer to the question: "Why are the fish on the reef so colorful?")  

One approach might be to Books searches like

     [ coral reef fish color ] 

but this kind of search is pretty open-ended; it returns lots of books (e.g., "reef fish coloring book") that aren't especially well-suited to what we seek.  

One way to focus the search (or, in other words, scope the search--see my earlier post about why scoping is a key skill for SearchResearch) is to use the Subject Headings. 

In this case, I'll go to the BISAC Subject Headings Complete List, and look for the subject "Science."  If I click on that link I'll be taken to the complete list of Science subjects (at least according to BISAC).  Control-F for "Icthyology" leads me to the subject heading: 

     SCIENCE / Life Sciences / Zoology / Ichthyology & Herpetology 

Now, if I do a search like this (in Books):  

     [ coral reef fish color subject:"SCIENCE / Life Sciences / Zoology / Ichthyology & Herpetology" ] 

I'll get a very focused set of results, one of which will very likely have what I'm searching for. 

Notice that I had to include the entire string of the subject heading.  (And using the code, "SCI070010" just won't work at all.)  

And, sure enough, the second book in the list "Fish: An Enthusiast's Guide" (Peter B. Moyle) has several very nice sections that describe why reef fish are colored the way they are.  (In short, there's cryptic coloration, countershading, poster colors, disruptive coloration, and so on. Fascinating stuff... and it's not all just camouflage.)

I'd argue that this would have been a difficult search to do without the scoping provided by the subject: field.  

Browsing:  One thing people say to me all the time (when talking about Books online) is "I just can't browse online books the way I browse books in a bookstore."  

I feel their pain--one of my very favorite things to do is to wander through a bookstore and see what's there.  We can't quite do that yet.  BUT we can give you an experience that's close to the sense of scanning the nearby bookshelves.  There are two ways to do this.  

Browsing Method #1:  Use the related books function.  When you click on "About this book" link (on the left hand side of the page view)... 

you'll immediately see a bunch of additional information about this book, INCLUDING "Related Books" 

Notice how you can scroll left and right to see more books that are closely related to this one. 

Browsing Method #2:  The other way to browse is by scrolling down and looking at the "Common terms" and "Subjects" (that is, the subject headings in the book's metadata).  Look at the following image....  I've scrolled the "About this book" view down far enough to see the "Common Terms" and the "Bibliographic Information."  

Note the Subjects list.  Guess what those are!  

You can browse subjects in Books by clicking on those links, which will then do the subject: search for you automatically.  (And note in particular, the last link is exactly the BISAC subject heading we got by browsing in their master list.)  

There's much more to say about this, but I want to wrap it up for today.  (We'll return to this topic.)  

Search Lessons:  First off, the subject: operator in Books is very powerful.  Once you learn how to use it (and remember how to get to the master list), it's your friend for life.  (Now that I know about to use it, my searches in Books have become more precise and relevant.  There's stuff in Books that I never thought I could find.)  

Second, remember the subjects list at the end of "About this book."  It's a great way to browse around, especially when you're just learning about a topic.  (As an example, check out the subject headings on the book "Your Guide to the National Parks." You'll learn about the space of National Parks and travel in the US very quickly.  I predict you'll find books by browsing like this that you'd never find any other way.  It is, in effect, powerbrowsing.  

Search on! (Subjectively!)