Friday, March 6, 2020

Jokes about finite automata

I try to lighten test anxiety by making my exams (1) feasible in time-constraints, (2) interesting, and (3) fun.

Yes, that's right, actual students (many of them!) have reported after taking them that tests are fun in my classes.

One thing that I do fairly consistently is to offer 1 bonus point at the end of the test if the student writes a joke. Usually I ask for a joke that is about the content that was being examined in the test, but I accept even the weirdest CS-themed puns.

The prompt was: Write a joke about finite automata.



Actual jokes according to my own peculiar sense of humor:

  • How much does an automaton weigh? An automaTON
  • Why did the NFA go to 4 corners? So it could be in multiple states at a time.
  • How did the NFA choose which classes to take? It took all of them, and then picked the ones it liked best.
  • We're all computers (b/c we answer yes + know)
  • Q: What do you call a robot working in the winter coat department? A: A push-down automaton.
  • "Want to hear a joke? DFA" - a rather mean-spirited Turing machine, probably.

Some people wrote a thing which was definitely on the part of the paper where I requested a joke:


  • Can't think of one, can you choose the best answer nondeteministically?
  • Why did the PDA get in trouble? He was on his PDA in class.
  • Finite automata are so finite that even humans get them.
  • I couldn't come up with a finite automata in the finite amount of time of the test. 

The prize for overall best joke that will definitely stay funny in new ways as the semester continues goes to this one:


"How does a finite automata decide where to eat? It accepts nondeterministically wherever it will be the most satisfied."


This post's theme word is metathesis (n), "the transposition of letters, sounds, or syllables in a word, for example aks for ask." The regular languages are probably closed under metathesis, if we cared to rigorously define that operation.

Monday, February 17, 2020

What is the worst security account question?

I take attendance by having the students answer a question.

What is the worst account security question? (Previously: 2016.)

Students came up with some bad ones, mostly classics:

  • name of 1st pet
  • favorite teacher's name
  • what is your name
  • hometown/first school
  • your password
  • hometown
  • I hate all of them
  • mother's maiden name is a classic
  • first vacation
  • what is you username?
  • where were you born
  • first job
  • what street did you grow up on?
  • 1st pet name?
The only outlier was the unusually-personally-invasive:
  • What was the first name of the first boy or girl you kissed?


This post's theme word is elutriate (v tr), "to purify or separate, especially by washing or straining." The account security question did nothing to elutriate spurious logins from authentic ones.