On Sun, 17 Jan 2016 14:07:13 -0800, DerbyDad03 wrote:

"When they use the 2 image reCAPTCHA system, the first image is the
control, the second image is the one they want to figure out."

Here is a clear example I saw today of the *control* word, I think:
https://i.imgur.com/cGFL5oz.gif

And, here is another example I saw today of the *easy* street numbers:
https://i.imgur.com/vTZtHFO.gif

However, what perplexes me are these types of *impossible* cyphers:
https://i.imgur.com/5eGAZ3I.gif

Where is the *control* word in this captcha I encountered moments ago?
https://i.imgur.com/V8dMAUx.gif

Of those last two examples, I can't imagine that *either* of them
portrayed a word in an OCR document, unless they are OCR'ing
documents after sending them through a washing machine first!

So, what's the OCR-corrective sense in the latter two captcha's?