Thread by @HeyChelseaTroy

I have been watching several online lectures and lecture playlists from different instructors lately.

I'm starting to have some aggregate thoughts about what makes a lecture work—or, more specifically, NOT work.

1/

Before I begin, two things

1. I'm a graduate school instructor. I have given lectures. I'm not the peanut gallery.

2. My sample is "Lectures that got to YouTube," so their quality probably outstrips the average.

In particular...

2/

I have seen very few cases where the instructor didn't prepare or didn't care.

So this thread is really "What can STILL make a lecture not work, even if the instructor cared about the quality of instruction and prepared for class."

3/

Among this sample (maybe 50 videos so far), when I see a lecture not work, it's because of one of two things.

1. Timing.
2. Scaling.

I'll address each in turn.

4/

Let's start with timing because that one is a lot faster to address.

It's not uncommon for an instructor to start out on the right foot, do fine for 80% of the lecture, and then run out of time and rush the ending in a way that crashes the entire knowledge transfer.

5/

Seriously. Four times I have watched the SAME instructor teach the SAME material in different years—one year where each session was 50 minutes and one where each session was 80 minutes.

In all four cases, the two versions were ALMOST identical for the first 35-40 minutes.

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After that, in the 50 minute version, the shit hits the absolute fan. In the 80 minute version, by contrast the instructor confidently and capably finishes the proof or whatever. The order of the years has not mattered.

/7

This is not always the instructors' fault. Sometimes they're handed a syllabus and told "You have to teach this material in this lecture. The homework covers it so you can't push anything."

This isn't the lecturer being bad at their job. This is academia expecting too much.

/8

My heuristic for whether this is going to happen has become "how often is the instructor checking their watch."

I've noticed, anecdotally, that instructors who check their watch several times BEFORE the 30 minute mark aren't generally having this happen to them.

/9

Now let's talk about the other thing: scaling. A lecture might not work because it is not the appropriate scaling for the audience.

What is scaling? I'm borrowing the word from, of all places, fitness instruction.

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Fitness instruction (well, GOOD fitness instruction anyway) does not target a specific movement or weight. Instead, it targets a specific STIMULUS.

The appropriate scaling for a given athlete is the one where they achieve the desired stimulus.

For example...

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...the target stimulus of a push up is to develop upper body pushing strength.

If an athlete cannot yet perform a push up, no amount of trying to do a normal push up will get them one—nor will it get them much upper body pushing strength.

So...

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...the instructor might have them do the push up on their knees rather than their toes, so they can build their upper body pushing strength rather than struggling around on the floor trying to do something they can't do, to very minimal productive muscle stimulus effect.

/13

Working on sets of push ups from the knees will develop the strength FASTER to do a push up from the toes than floor-flailing while trying to do a push up from the toes.

I KNOW, you're thinking "naturally the crossfitter has to drag crossfit into it, typical."

IN FACT...

/14

...one of my most memorable intros to scaling happened BEFORE I joined a gym, at @ruby_dcamp.

DCamp starts with pair programming speed dating. For 6 consecutive 45 min sessions, you write Conway's Game of Life with test driven development.

To make things interesting...

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...each session has unique restrictions on how you write the game.

It was my first year as a programmer; I had a lot of enthusiasm, but that was about it. For session 4, I got paired up with this Santa Clausy character and we were told to be "adversarial."

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"Adversarial" test-driven development is when one pair writes a test specifying some system behavior, and the other person tries to write code that makes the test pass while specifically NOT doing what the system is supposed to do.

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Santa Claus immediately assigned me the role of test writer and asked me "Is it okay with you if we try this rule with something simpler than Conway's Game of Life?"

I had already failed to write this damn game 3 times by then, so I was stoked about this development.

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He then proceeded to have me write a method checking that two inputs (a dividend and a divisor), when divided, produced the appropriate quotient and remainder.

I did what you'd expect: I wrote a method that checked that quotient*divisor + remainder == dividend.

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SO THEN THIS JERK

calls my method with, like, 40, 9, 5, and -5.

9 * 5 is 45, which, with 5 subtracted, produces 40 (yes, dear readers—it DID turn out that he was a cryptographer).

His inputs passed my test...and were CLEARLY NOT what I expected as input.

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From that session, I got a better understanding of adversarial testing because my pair chose a problem that was SCALED appropriately to my experience level.

If we had done Game of Life I'd have been hopelessly lost and counting down the minutes for the session to end.

/21

Back to lectures.

When the instructor cares and prepares and nails the timing and the lecture still "doesn't work," it's often a scaling mismatch.

Either I don't have the prerequisites to understand the material and so the lecture is too dense for me, or it's too basic.

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Now, the REALLY hard thing about scaling is that, at least in the classes I have taught, the students come in at all different levels of experience.

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In almost every class, I have at least one professional programmer who is here to fulfill a degree requirement on a technicality, and I also have at least one person who found out what a variable was less than six months ago.

Even when there are prerequisite courses...

/24

...in my experience, that doesn't guarantee a minimum knowledge level. For many reasons:

- maybe a prior instructor let the student squeak through
- maybe the student cheated to pass prereqs
- maybe the prereq isn't standardized on the material it teaches
- and others too!

/25

So, once again, an instructor failing to nail the scaling for every member of the class is not necessarily the instructor's fault. In fact, it's almost inevitable.

This is, believe it or not, pretty hard to solve.

/26

In WATCHING lectures, I have solved it by...well, skipping the lecture if it's too basic.

If it's too dense, I go find a video by a different instructor of either that same material or prerequisite material, and then I come back.

That doesn't work in a colocated class.

/27

In GIVING lectures, I do a few things about scaling.

1. When I make my lesson plans, I center the student who will need the MOST support, not the least.

And I'd like all academics to go back and read that sentence again because I see A LOT of the opposite in lectures.

/28

It's common for instructors to center the strongest students on the material. I get why it happens.

- they're usually more vocal in class
- more "interesting" material to the instructor
- instructor probably WAS one of these students
- "It's where the whole class should be"

/29

I'm not into it, myself. First, my job is to teach. I focus on the students that need taught. If students are paying for instruction they don't need on some technicality, that's none of my business.

Second, it's actually surprisingly hard to make lectures "too basic."

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Like, a surprisingly large number of "strong students" forgot the basics, or have been doing something wrong the whole time, or keep a better grasp on the advanced material later in the class if it follows directly from MY wording of the first principles we started with.

/31

Do I get a few "this class was review" comments at the end of the quarter? Yeah, well, when you're working on a degree in the field you already work in, that'll happen.

I get a lot MORE "Holy shit, this is exactly how I needed this explained."

All of that said...

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I DO want students of all backgrounds and experience levels to get a lot out of my class.

In crossfit classes, different athletes will do different scalings of the same workout. It's possible to get some scaling variation.

Ways that I do it:

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For an activity, I'll provide five questions of escalating difficulty, and end the activity after the slowest group has finished question 3. Meanwhile, the faster groups got into 4 and 5 for more enrichment.

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Also worth noting: if I see a trend in which groups tend to move a little slower or get lost faster, I make a note to prioritize them for support.

I still visit everyone, but I'll make sure this group isn't lost FIRST.

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As often as I can, I give my students opportunities to choose their own interim and final projects. Frequently, more advanced students want to do more ambitious things, and I am happy to provide them with individual guidance in office hours.

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So my formula is, lecture for the LEAST background, while creating room for students with the MOST background to try out activities and assignments at their experience level, with gradations in between.

It's some extra work for instructors, but in my opinion, worth it.

AND

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AND, you might be surprised.

On a few occasions I have had students start out with less background and end up progressing immensely because they finished up the harder activity questions outside of class.

(it helps if the questions are interesting. I try hard at this).

/38

There's also nothing wrong with calling out a prerequisite.

"For this lecture, you need to know X" is fine IF the lecture is recorded and people can pause it, go find material on X, and come back to this later.

(That doesn't work live, so if you're gonna do it...

/39

...make damn sure everyone in your class is supposed to have learned X).

OK, soapbox over I think. I gotta go watch a prerequisite lecture for something :).

40/40