Author: John Quintanilla

I'm a Professor of Mathematics and a University Distinguished Teaching Professor at the University of North Texas. For eight years, I was co-director of Teach North Texas, UNT's program for preparing secondary teachers of mathematics and science.

YouTube’s Automatic Closed-Captioning of Mathematical Speech (Part 1)

The biggest change that I’ve made to my teaching in the past ten years has been posting review videos for my students as they prepare for exams. The playlists that I post for my students can be found at my YouTube channel. The production quality of the videos is definitely low-budget: I just placed a ruler along the top of two textbooks of equal height, balanced a webcam on the ruler to point downward, and then recorded myself as I wrote out and talked through the solutions of the review problems. I’m not going for high production value in my videos, unlike excellent sites like Physics Girl or Numberphile, since my target audience is deliberately narrow (the students in my classes and, more recently, in some of my colleagues’ classes) and not worldwide.

For what it’s worth, I have recorded roughly 650 videos, each usually between 3 and 10 minutes long, which have collectively amassed over 200,000 views since I started recording them in 2011. Not bad for your friendly neighborhood mathematician.

Posting these videos have spurred some immediate changes to my pedagogical practice. First, I no longer give review lectures in class immediately before my exams. Instead, I ask students to take a shot at completing the review problems on their own, asking them to watch the videos only to check their work or else to get the answer if they get stuck. Students are still welcome to come to me for help during office hours or by appointment, but they’re expected to watch the videos first. In my end-of-semester evaluations, my students seem to really appreciate having these videos. They tell me that they like having after-hours help while studying for their exams and that, unlike a regular review lecture, they can rewind the video and start over again if they need to hear a concept repeated.

Another positive development is that eliminating the review lectures have given me three or four hours of extra contact time each semester with my students. Rather than add new material or cram in extra examples, I’ve mostly used these extra hours to slow down the pace of my lectures and to include group activities and other forms of student engagement during class time. I’m particularly happy that I have three dedicated days in my Discrete Mathematics class when my students can practice their new (for them) techniques of writing mathematical proofs. If they get stuck, I’m around to answer questions about the mechanics of proof-writing. If they don’t need help, they can get immediate affirmation from me about whether or not their proofs are correctly written. Discrete Mathematics is our math majors’ first introduction to writing mathematical proofs, and that my students have their initial struggles with this technique in class as opposed to when they do their homework on their own time.

So I intend to maintain this practice for the rest of my career.

However, there’s been one complication that I should have foreseen in 2011 but didn’t: the Americans with Disabilities Act. This had been mostly a potential problem for me that I hid away in the deep recesses of my mind until last semester, when a student with a hearing impairment was enrolled in my class.

In my next post, I’ll discuss some humorous examples of erroneous closed-captioning of mathematical speech which were automatically generated by YouTube.

Predicate Logic and Popular Culture (Part 206): Jack Johnson

Let H be the set of all things, let T be the set of all times, let G(x) be the proposition “x is good,” and let R(x,t) be the proposition “x remains at time t.” Translate the logical statement

\forall x \in H(G(x) \Longrightarrow \forall t \in T(R(x,t))).

This matches a line from “Mudfootball” by Jack Johnson.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.

Predicate Logic and Popular Culture (Part 205): Bob Marley

Let T be the set of all things, let L(x) be the proposition “x is a little thing,” and let A(x) be the proposition “x is going to be all right.” Translate the logical statement

\forall x \in T(L(x) \Longrightarrow A(x)).

This matches a line from “Three Little Birds” by Bob Marley.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.

Predicate Logic and Popular Culture (Part 204): Billy Joel

Let T be the set of all times, and let W(t) be the proposition “She is a woman to me at time t.” Translate the logical statement

\forall t \in T( W(t)).

This matches a line from “She’s Always a Woman” by Billy Joel.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.

Predicate Logic and Popular Culture (Part 203): Bill Withers

Let P be the set of all people, let T be the set of all times, let P(x,t) be the proposition “x has pain at time t,” and let S(x,t) be the proposition “x has sorrow at time t.” Translate the logical statement

\forall x \in P( \exists t_1 \in T(P(x,t)) \land \exists t_2 \in T(S(x,t)).

This matches a line from “Lean on Me.” Note: while I think the translation above matches the intent of the song, a case could be made that, literally rendered, the “there exists” symbols should come first — that there’s a single time that everyone has pain at that one time.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.

My Stanford Story: Madeleine Gates

In honor of her team winning the national championship on Saturday night, I’m reposting this video about Madeleine Gates, who is both a middle blocker for the Stanford women’s volleyball team and also a graduate student in statistics. There aren’t a whole lot of graduate students who play NCAA sports (which would necessarily mean finishing their undergraduate degrees in three years or less), let alone play at an exceptionally high level while also pursuing an advanced degree in a field as demanding as statistics. I really enjoyed watching this.

Here’s the video of championship point from Saturday night. Gates had the final swing.

Predicate Logic and Popular Culture (Part 202): The LEGO Movie

Let T be the set of all things, let p be the proposition “You’re part of a team,” let A(x) be the proposition “x is awesome,” and let C(x) be the proposition “x is cool.” Translate the logical statement

p \Longrightarrow \forall x \in T(A(x) \land C(x)).

This matches the opening line of “Everything is Awesome!!!” from The LEGO Movie.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.

Predicate Logic and Popular Culture (Part 201): Hamilton

Let T be the set of all times, let time 0 be now, and let L(t) be the proposition “I like the quiet at time t.” Translate the logical statement

\forall t \in T(t < 0 \longrightarrow \lnot L(t)).

This matches a line from “It’s Quiet Uptown” from the hit musical Hamilton.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.

Predicate Logic and Popular Culture (Part 200): Spider-Man

Let T be the set of all times, and let R(t) be the proposition “I will rest at time t,” and let M(t) be the proposition “You are unmasked and eliminated at time t.” Translate the logical statement

\forall t \in T(\lnot M(t) \Longrightarrow \lnot R(t)).

This matches a line by J. Jonas Jameson in the 1990s Spider-Man cartoons.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.

Predicate Logic and Popular Culture (Part 199): Justin Bieber

Let T be the set of all times, let K(t) be the proposition “You knock me down at time t,” and let G(t) be the proposition “I am on the ground at time t.” Translate the logical statement

\forall t \in T(K(t) \longrightarrow \lnot (\forall s \ge t (G(s)))).

This matches part of the chorus of “Never Say Never” by Justin Bieber.

Context: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.