If you were in school anytime in the 40-year period, starting in about the 1960s, you probably remember the overhead projector. What it sounded like when it turned on, what it looked like to have someone standing over it, drawing, trying to make sense of something as you were looking at it on a big giant screen that maybe you couldn't even see very well. The overhead projector isn't so much a part of schools anymore, but it changed the way we learn forever. From The Verge at Vox Media, this is Version History, a show about the best and worst and weirdest and most important products in tech history. I'm David Pierce, and today on the show, we're going back to the classroom.
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All right, we're back. The projector is on. Let's do this. Joining me in the studio at The Verge is Jake Kastrenakes. Hey buddy, nice to be here. How many visceral memories does this thing bring back for you?
I completely forgot about this piece of technology until you mentioned it, and now it's just like, how did I... It's such a beautiful object.
It is. Was this in your classrooms growing up?
Oh, constantly. And I feel like it was a very exciting day when the overhead projector came out. Like, I don't know, it spiced up the classroom. This was the only technology available.
This and screens that they pulled down from the ceiling. This is what we did in our classrooms.
Also joining us remotely, Antero Garcia, a professor in the Graduate School of Education at Stanford. Hello. Welcome to the show.
Hello. Yeah, thank you for having me.
Is this thing a part of your education experience? What do you remember about overhead projectors? This is deeply nostalgic for my K-12 schooling experience. Six years after going to college, I became a high school English teacher, and these were largely kind of stacked in the book room at that point. Right? So there was a blip by the time I graduated from high school to when I became a teacher when these just disappeared, were obsolete. So this thing turns out to have a very fascinating and incredibly long history. And as we are wont to do in the show, we're gonna go all the way back to the mid-1600s. I'm really sorry.
Every once in a while, we have to go back to the mid-1600s, which starts with a Dutch scientist whose name is, I believe, Christiaan Huygens is how you'd pronounce that, who invents a thing that comes to be called the magic lantern. And this thing is essentially, it uses an optical lens, candlelight, and painted glass slides to take a thing and project it larger. That's the whole idea, right? The idea of 'I have a thing and I need to make it bigger so I can show it to people' turns out to be kind of a need as old as time. And he invents this thing with very simple technology that takes an object and projects it. And this is what we do. So before this, there had been people who had basically been finding ways to reflect sunlight through a transparent object to project images. The magic lantern is the first one that I think you could sufficiently call a piece of technology. But again, like this idea of 'I have a thing that's this big and I need to show it to people who are not right next to me' — extremely old idea. And like you even go back to, you know, centuries ago, there were people teaching crowds, right? Like this is a thing we've needed for a very long time. The idea that they start to come up with is actually fairly recognizable as a slide projector. Like this is just, we built slide projectors for 400 years, which is kind of wild. And there was a great marketer behind it who coined the term magic lantern. It becomes a whole thing. He becomes a traveling salesman. He travels all over Europe to demonstrate it and sell it. Makes a bunch of money. It gets very exciting. Let's just blow through 300 years, right? That keeps happening. The technology keeps getting better. They start using them in shows and presentations. Anything you can do kind of in front of a large group of people. This is not really an education thing yet. It's an entertainment medium.
So, we have a lock on projecting fully horizontally, but the idea of a vertical component, that has not yet entered.
Minds are going to be blown.
This is the innovation that is...
I could point something at you over there. That's all we've got. I don't want to dwell too long in here, but basically the technology gets better. Everything gets cheaper, everything gets easier, everything gets smaller. We start to invent new light sources that are better than candles. The first thing I think you might conceivably call an overhead projector starts to show up in kind of the 1850s-ish, still in Europe. We're in France in this case. Shout out to Europe for inventing the OP, as everybody calls it. The cool kids call it the OP. But at this point we have something, and I will show it to you now, that is relatively recognizable as an overhead projector. And you can see it takes light from below, sends it up, projects it out, right? Like this is the thing. It's actually very sort of elegant and simple in its way. This looks a lot like the thing that is on the desk beside us right now. This looks very much a lot bigger, but like fundamentally these are the same components.
My other favorite thing is that at this time these are known as viewgraphs, which I think we could all agree is a vastly better name than overhead projector.
Antero, agreed? Are we around... viewgraphs is great. Yeah. Viewgraphs also good, like a good math rock kind of band name. I think the viewgraphs, the view, that is good. I like that a lot. So this all keeps happening, and I want to now stop and pause on the story of the overhead projector in the 1940s. The 1940s brings World War II, and overhead projectors start to become very important because all of a sudden during World War II, a thing that happens over and over and over again is that the US Army brings in new recruits in vast quantities who all need to get up to speed on the war effort really, really, really fast. Which means there is not a lot of time for one-on-one education. There's not a lot of time for anything. There's just time to shove a bunch of people in a room, explain to them what they need to do, and send them to war. And so this idea of needing a tool you could use to instruct people quickly and en masse, which now sounds very normal, becomes a big important deal. And so the US Army ends up buying and helping fund the ongoing development of overhead projectors. Antero, at the risk of asking like an insane question about thousands of years of education, this idea of sort of mass education and teaching a bunch of people all at once, in the scheme of things, is actually a relatively new construct, right?
Yep. Yeah. This is, I mean, when you talk about the 1940s, right, we're now in kind of like the industrialization of public education, particularly in the United States in this period, right? So, the idea of moving, you know, shortly, not too long before that period is when we're moving from like the one-schoolhouse kind of classroom setting to broader systems of public schooling. The road systems throughout America and the interstate system is going to allow us to create bigger systems of busing that allow for school structures to sprawl in different kinds of ways. And so, the idea of mass-producing classroom education and similar experiences across schools is fundamentally changing here, right? I think maybe just the other interesting thing to consider is, you have, from what I'm seeing, the overhead projector is situated at a particular distance from the screen in order to properly crop the image, but if you wanted to, if you had a bigger board on the other side, you could move it back to make the image bigger, in ways that today's technology, the screen size is fixed. It's bigger oftentimes, right, in terms of screens, smartboards, flat-screen TVs. But the overhead projector gave us a lot more flexibility in terms of projection, and fidelity, in ways that we've lost in our race towards maybe more kinds of options with what we can do with our screens.
Yeah, there's a really interesting sort of arc of education that the overhead projector kind of sits in the middle of, where it seems like we had gone from very individualized instruction where everybody is sort of sitting looking at a textbook or looking at a handout or something, and then we have this big movement of everybody looking at the chalkboard or the overhead projector or the whiteboard, and with computers we've sort of gone back to everybody is kind of in their own little private world at their desk. Antero, I have one more concept I want you to explain at this particular moment if you can, which is the idea of the visual instruction movement, which I think kind of goes along with all the stuff that we've been talking about. And I don't need you to explain the movement necessarily, but there's this shift in how we think about how to educate kids towards something more interactive and visual. Can you just kind of talk through what was going on there?
I mean, I think maybe one way to kind of think about this, and this is the interactive component that's also coming up here, right? I think there's something to consider in terms of the communal and collective nature, right, of visual communication, right? So when we're looking at something together, when we're exploring the images of what's learning instead of just purely based on words and book-based forms of education, there's an understanding of knowledge as something that happens with other people, right? This is a large part of sociocultural learning theory. Just to say like there's a large theory that's happening probably concurrently also in Russia. If we think of Vygotsky as a kind of key figure in a lot of this, a lot of the ways that we think of the orientation of learning structures today really is about how do we learn together and what are the kinds of stimuli that allow us to do that, right? It's oftentimes images. This gets us to probably later on down the road several generations that concerns around screen time and things that are happening today, right? But for now the screen is largely benign, and to your point, there's a lot of power and privilege of who gets to wield the pen or the stylus or whatever the thing is that is now drawing people's attention to it. I think of this almost like a baton for a conductor, right? The thing that's holding people's attention in a classroom in some ways.
Totally. So, all of this is kind of converging at once, right? You have the war effort, you have the industrialization of public education as you're talking about. You have this new way of thinking about education. All of this is just crashing together in the 1940s. And then when the war ends, as often happens with war efforts, suddenly there's a new kind of device and a new kind of technology that is suddenly everywhere. It has been created in mass quantities for a war effort. Now we need somewhere else to put it. One other invention we should give a brief shout out by the way is cellophane, which is also invented in the early 1900s, and without which none of this works. So...
Yeah, thank you for being transparent, bringing the transparency to the overhead projectors.
Exactly. You're great. We couldn't have done it without you. So, there are a couple of companies after the war effort that really start to take off. 3M, which I think we've all heard of Post-it notes lore, takes the idea, invents the stuff, and I think 3M is probably the company most responsible for taking the overhead projector completely mainstream. This is a 3M projector. This is basically when I close my eyes and think of high school, it looks an awful lot like this particular projector. And I think that's probably true for most people. So 3M does a couple of really interesting things with overhead projectors at this time. And there's this guy Roger Appeldorff who deserves some of the credit for it. So in the late 1950s, Roger Appeldorff takes the idea of cellophane and basically makes a bunch of new kinds of transparencies that you can print. You can take color images and actually like improve the quality of them. He improves the whole idea of what a transparency film can be, and helps create a lighter and lower-cost version of the projector. There were customers of 3M who were telling him they wanted an overhead projector that could fit in a briefcase or that was the size of a briefcase. Why people wanted to like lug around overhead projectors, I could not tell you.
Do you think it was like a sales thing? Like I can absolutely imagine that.
Oh, that's an interesting point, right? Yeah. What do you think on the train? The laptop overhead projector. This is the...
Yeah, it's a good question. So I actually think, Jake, you might be on to something. One of the things they asked for was something that would unfold and light up and just sort of spring to life the minute you start it.
There's some Rube Goldberg thing in like a conference room table.
They wind up building a version of just that thing. The prototype is so expensive and so complicated that they attempted to basically kill the project entirely. But by the early 1960s, Roger Appeldorff and his team invent the first overhead projector with one very important new piece of technology, which is called a Fresnel lens. And the Fresnel lens, to spoil a little bit of the 'how does this thing work?', basically takes a large lens that is able to project light over the entire surface of this thing and makes it smaller and makes it thinner. Jake, I have a task for you.
I would like you to explain as scientifically accurately as possible how an overhead projector works. I'm staring at it right beside me and it looks pretty simple. As best I can tell, this is a large box with a light in it. There's some glass on top of the light which allows you to place the transparency on top. The glass has these sort of rings etched in throughout it. And I'm wondering if... to be honest, I don't really know what a Fresnel lens is, but I'm wondering if... Okay, this is the thing. You need something to condense the image so that it can hit the mirror above it and then hit out the other side. And so I'm assuming this large piece of glass is actually somehow warping the way that the light comes out so that it hits the mirror correctly as a flat image once again. Although there isn't... Sorry, I should say when it hits it, the light shoots up. There's actually another lens up top.
So, there seems to be one lens that... what's the right word for this? Like, it's like condensing the image, and then there's another that's re-expanding it, and it's hitting a mirror. That being said, I still am confused why this thing is so large and so hot and requires a fan. That is wild. This thing is very warm beside me. So, that's my answer.
You are closer than you think. We have a diagram here if you're watching, and I can just...
Can I tell you something? I didn't look at the fact that there's a diagram.
You did a great job. Honestly, I'm very proud of you. You essentially described it correctly, and again, the thing that you identified where there is this very large square space here, which is what you need in order to have a piece of paper or something to show to your students or whatever, like you need real surface area here, but to take a lens this big and project, this would also have to be enormous. So this is the magic of the Fresnel lens. And the example everybody always gives is a lighthouse, right? Like what a lighthouse does is it takes a bunch of light that comes out of a lamp, right? It takes a bunch of very bright light shining in all directions and it focuses it into one beam of light. That's what this lens does. That is the magic of the Fresnel lens. And it's able to do it in a way that isn't monstrous, because otherwise trying to do that thing would require a monstrous, incredibly expensive lens. So, what it does is there's a lamp underneath here that shines light up. This takes that light... I'm going to get so many emails about this. Just know that I'm doing my best, everybody. That's all I ask. This...
Fresnel is turning in his grave.
Yeah, exactly. This takes all of that light and literally, like a lighthouse, focuses it up into this lens. The lens then takes that conversion. So, you can see this lens is concave. It focuses it yet again up into this mirror which flips it upside down and points it at the screen.
That's the whole thing. It shoots light up, turns it that way. And everything else in it is about focus essentially. It's about shrinking the picture essentially to be able to point it again at the wall which blows it up. It's a remarkable piece of very simple technology. And you can sort of see again this is why we started in the 1600s, right? The idea has not changed. I have a thing. I want to point light at it so it'll be bigger over there. Is like you can figure it out by accident holding a thing up. Do you know what I mean? Like if you've seen your shadow, you sort of understand the thesis here. But this winds up being a remarkable thing. And then again, you can, as you can hear...
Yeah, cuz this thing gets hot. So, all right. That is how an overhead projector works. If you know better and we got everything wrong, I'm so sorry. So, we get to the point now where they make a thing that is smaller, it's cheaper. Again, they've used this new kind of lens before these, they were even bigger than this. This is the smaller one.
They used to fill a room.
I mean, more or less. And immediately everybody wants these. Businesses want them, schools want them, government agencies all want them. And one of the interesting sort of side stories here is that the Fresnel lenses were so impressive that 3M actually went looking for other places to put them. They were like, 'We've built this amazing technology. Where are they going to go?' They go all kinds of fascinating places. If you've seen those like sort of fluorescent, lightly reflective traffic signs, do you know what I'm talking about? That kind of glitter at you all the time.
Fresnel lenses often made by 3M.
I'm telling you, deep rabbit hole. I recommend everybody go down it. That is the end of our version of the science project here. But the big new place that these start to land, until now they've been a military thing and they've been a business thing. Now they start to really land in the classroom at this point for as far as I can tell a pretty long time. The chalkboard had been the main character in the classroom. Is that right? This was the thing that everybody used everywhere.
Yeah. Chalkboard. I think, and largely I think including the overhead projector, we've basically been replicating the chalkboard in classrooms since then, right? So chalkboards, overhead projectors, whiteboards, smartboards, and largely, you know, digital screens today where people are largely plugging in laptops and typing on them is still about projecting some kind of information to a group in ways that hold power and orient people towards particular spaces and classrooms, right? Like there's a fixed nature of what the quote-unquote front of a classroom is because of the nature of a chalkboard and then the overhead projector which gave us much more flexibility than other kinds of devices that would come later.
One other thing I did find that I think lends to the 3M salespeople were also very good at this argument is that what 3M started doing was bundling transparencies with both projectors so that you could sort of easily start using them, and with textbooks. So they would ship textbooks and sort of lesson plans that were made to go on the overhead projector. And I think one of my great learnings from all of the research for this season of Version History has been anything people can do to make teachers' lives a little bit easier turns out to be very powerful and very hard to walk away from because teachers are so overwhelmed, so overloaded, have too much to do all the time. And if you can just find a way to make a teacher's life a little easier, you can almost always worm your way into a classroom for better or for worse. And there are some of both of those in these episodes. But that just seems to be part of this. And 3M understood that and was like, well, we're going to make one little part of your teaching life easier. And it really seemed to help. As all of this is happening, we need to shout out one other very important and very influential use for overhead projectors, which was bowling alleys. There was this thing called the Telescore. And the Telescore was essentially, you know, how you go to a bowling alley and you sit down at the thing and you program everybody's names and then it puts all your scores up on a TV, right?
Jake, you're looking at me like you've never been bowling.
No, no, no. I just never believed there was anything before the TV. The TV was there for all of history.
So, there was, fun fact, and it was called the Telescore. And basically the way it worked is it was this large desk and the desk was also an overhead projector and you would sit down and you would program your scores. It would then project all the way down the lane, two lanes at a time, the names and scores. This is revolutionary in bowling. All of a sudden you can get at-a-glance scores for your team, for everybody. This revolutionizes bowling. And just to anchor us in time, other things in this system, ashtrays. There's an ashtray in the Telescore desk. There's a patent for this that includes every part of it, including like the chair, and there's just an ashtray in there. It's delightful. But anyway, so shout out to the Telescore. The OP is taking off. Let's take a break and then Antero, you're going to help us figure out how this completely reinvents the classroom. We'll be right back.
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All right, we're back. It's now the post-war era of the United States in particular. Overhead projectors are suddenly everywhere. But I want to back up just a tiny bit with you in particular, Antero. You wrote this thing that I've been thinking a lot about in preparing for this. You wrote it several years ago, but you used the phrase to describe teachers as environmental designers of classrooms. I think that ends up being really important here. Can you just describe what that means?
Yeah, I think oftentimes we think of teachers as disseminators of content or facilitators for what kids do to learn. But part of that is, you know, creating the space in which, the space and conditions in which kids of all ages are able to learn, right? And for me that is, and when we think of the environment, it's what are the ways that a classroom or a learning space is set up in order for kids to most effectively engage with the learning task in front of them. And so that is a task of designing and thinking about curating one's space. I oftentimes have thought about this in terms of ways kids can be involved in that process, but the furniture and the equipment in a classroom kind of dictate and limit what's possible in a space, right? So you oftentimes have this big clunky teacher's desk, we probably have like a similar kind of vision of like an industrial metal thing, the broken chair that kind of fiddles around that the teachers have power in because it's the only thing with wheels in the room. And the student desks, right, that are bolted in place and orient people's bodies in particular ways. And so just to say our choices around how we environmentally design our classrooms are hindered by what's possible in any given space, right? So the public classroom that I taught in for many years in South Central Los Angeles, the desks didn't have a lot of agency of how kids could move, right? And they were set up for particular kinds of bodies and particular shapes and sizes. And so, you know, the overhead projector in a similar way orients us to look in a particular direction, right? We all need to look towards the sage on the stage kind of model, right? There's an authority figure, and as we're looking at this overhead projector, there's only room for one or two people, and hopefully the other person is left-handed, to be next to an overhead projector, almost like its own podium or lectern. There's not space for collaborative work in front. It's really for an individual to be next to this device, and as a result the rest of a classroom is supposed to be, their eyes are gazed towards this particular screen and what's being projected from it.
Yeah, this ends up as far as I can tell being actually somewhat controversial and kind of the main issue scholars raise even at the time about overhead projectors, that they use the phrase power imbalance, and that all of a sudden instead of having a bunch of people more or less on the same plane of interaction, you have somebody standing at a thing, literally light shining on them as they do the work. And sometimes you might have had your classroom be darker so that you can see it better. So you've created this thing in that like, I am God and you are watching me. And I think that goes to what you're describing, that really does change the feeling of being in a classroom from being something sort of interactive to being something much more one-to-many.
Yeah. I mean, we've always had, you know, those kinds of power structures. I think maybe a possibly more benign example of this, right, is children on a rug for story time, right? You can kind of think of like they're all looking up at an individual holding a picture book in front of them. And in some ways the overhead projector is just the more industrial version of that, right? Is one way to think about this. But yes, like this is a way to quote-unquote get kids in line and pay attention in one particular way. And those are the power structures that we still largely manifest in schools today, right? The overhead projector, I think, isn't the thing that dictated this kind of process, but helped guide the kinds of processes of nationalizing a curriculum, as much as that's not a thing that we've tried to do until fairly recently, right? The idea of having some kind of textbook-driven approach towards how we educate and school young people, the overhead projector allows us to do that, right? So to your point of textbooks, textbook providers have overhead transparencies that go out to millions of students across the country. All of a sudden everybody's looking at the same thing in the same kind of direction with the same fidelity for the most part, right? I think there's a useful way of thinking of that as a controlling mechanism, right? The same way that once you know the printing press nationalized learning outcomes in Europe for many years, right? In the same way, right, that the overhead projector could be seen as something that nationalized learning opportunities for both better and worse.
Yeah, that's really interesting. I think the flip side of that though is I think one generally received great change about this was that it turned teachers around, that instead of for years standing at the blackboard writing something with your back to the kids, you can now stand here, the screen is behind you, but you can actually be operating the class while also looking at the class. And like, Jake, this strikes me as a big change. Like I think about me as a teacher, I'm going to act very differently.
It does seem important for teachers to be able to, I don't know, see if their kids are paying attention at all.
Yeah. There was so much at the very beginning that was like the best thing this is going to do is help teachers with unruly children, which is very fascinating. But it makes a ton of sense.
Does that track for you as a sort of big change again in that same relationship you're talking about?
Yeah, it's a literal 180, right? You get the teacher who's actually able to see their kids while they're talking to them is a pretty good transformation. I think, you know, that's a really nice shift from the way the chalkboard operates. But, you know, I think this is just kind of one of those kinds of considerations that makes the space design differently.
Yeah. Yeah. I totally agree. One of the things I had never really thought about, but turns out to have been really true, is that people really had to figure out how to use these things in a way that it feels sort of obvious, right? Like here, here's the thing. You write on the thing, that's how you do teaching. But it turns out there are all kinds of challenges that come with a device like this that you have to figure out. If you have bad handwriting, blowing up bad handwriting makes bad handwriting worse. If you have a lot of text, like let me just give you an example. Any transparency with a lot of text on it is hard to read in the best case and actually sort of physically painful in some cases because these things are not very high resolution. You're often sitting pretty far away. So to ask kids to read a lot of text in this style is actually very hard. And a thing that a lot of people had to learn because so much education is about showing lots of text and learning how to use these things properly becomes a really complicated part of the system. You just operate this differently than you would even like a chalkboard. So there were a lot of lessons, there were a lot of videos being made by exam boards and education departments saying here are some of the best practices. Can I actually show you just a couple of clips from one video showing people what you might do on an overhead projector?
So, this video is from 1960 and it is in the way a lot of 1960 videos are, like a 15-minute-long infomercial for a product. And I just want to play you a couple of different clips from this video where they really try to make the case for why these exist and what you can do with them. Here's the first one.
It enlarges the material on the screen so that everyone in the class is able to read it easily.
So you can see there's an old-timey projector and a guy is showing them bits of text. And this is...
All room lights can be left on when the projector is in use, making it easier for the students to take notes.
During the presentation, the instructor is able to remain in the front of the room facing the class.
So this is the stuff we've been talking about, right? The sort of basic things that become possible.
He can control the rate of development of the material and can vary the presentation both orally and visually.
It's hard to know looking at the video clip, but I can't read a single word that is up on that screen.
Yes. So, this ends up being not a very good idea. Again, that's a very simple one. That's at the very beginning of the video. It's like, here's why this is good. Really love that he says that, the narrator says 'he' because he's also the projectionist. The idea that this person is both teacher and projectionist I think is actually kind of a great way of thinking about this. Towards the end of the video they get into here's some of the wild stuff you can do with all these materials on an overhead projector. I just want either of you to tell me if you've ever seen someone do this with an overhead projector.
Another application of polarized light involves this motor-driven Polaroid disc which is attached to a projector in combination with strips of polarized tape which are placed on the acetate sheet of an overlay.
We're looking at like chemical diagrams of some kind. This all kind of looks like a, I think it's a battery or some kind of transition.
Tape covers the drawing. The appearance of movement is obtained.
Mind-blowing. You can make the transparencies... Okay, that rules. That's fantastic.
May also be placed so that the movement appears to be in the opposite direction.
Oh my god, this is fantastic. Why did my teachers never do this?
There's like a whole attachment port on this projector that I have never in my life seen.
Yeah, you need a new firmware update for that projector.
Yeah. So again, I think that's a particularly extreme example, but there is this real sense of like, this is a new piece of technology that we are going to explore and figure out new things to do with. It is so interesting discussing this in light of like, sorry to bring this up here, but like AI and so many other new technologies where it's like, we're like, hm, this exists, this seems powerful, how can we use it? Is it valuable? Should we put it in the classroom? And it's like the overhead projector, there are obviously many advantages, but a teacher doesn't need to use it for anything, right? They've been teaching these classes for years without these things. They didn't necessarily need... And so they have to provide some tangible advantage. And I don't know, that cool moving diagram was pretty sweet. So I guess this is one of the things I've been thinking about a lot in this case is there's clearly a sort of utopian period at the beginning of this where everybody is like, what new thrilling stuff can we do? What's so exciting? But then you go back to like teachers are overworked and I don't think are typically in line to spend a lot of time learning a new piece of technology. So does something like this just kind of immediately settle and normalize and it's like we spend a little bit of time, everybody goes to the training, they learn don't write too much text, have simple layouts, and it kind of calcifies. Like it doesn't seem like there's a ton of new ideas about overhead projectors for a very long time after this.
I think it became pretty routine and fixed, right, in terms of knowing that it was an ingrained part of the infrastructure of what was in most classrooms at the time, right? We just kind of knew that you would see the little boxes for the overhead projector bulbs, right? In classrooms. So like this was a part of what we understood the classroom to be. The imagination around what it does, I think, fizzled out because it functioned largely on its own. You didn't need to go to a lot of training in order to know how to use an overhead projector. You didn't have to update its software, right? You didn't have to worry about annual agreements around it, right? To the AI of it all, right? Just to kind of... well, we can come back to textbooks as its own kind of technology that we'd probably want to trace in some ways. So if textbooks and textbook companies have a lot of control over what happens in schooling and schooling practices today, the, you know, I think of the bookroom and the ways we would take kids to book rooms and they would march back with these big books and this like physical space where textbooks have... that's not how textbooks operate today. Like textbooks are literally software, and as a result textbooks are constantly changing and for the most part most textbooks today have AI stuff embedded in them for better and worse. I would argue largely for worse, right? That they're bloated and don't actually function in the same way that the textbook that I went to school with and that I used with my students operated in the past. And so in some ways, right, the kind of beautiful nature of the overhead projector is it functioned exactly as you needed it to. And assuming that the bulb was working and that you had a cord that was long enough to reach the wall, you knew exactly what it was going to do and was always going to do it in that way, right? Like the thing that you have displayed next to you worked exactly how it did 60 years ago. And assuming you can still have a bulb 60 years from now, it will continue to do exactly what it does now.
Yeah. And I think that winds up being a huge part of its power and b a huge part of why it was very hard to...
get rid of, for better and for worse. Even once we maybe had something better, which actually kind of leads to sort of the next moment in the story, which is we get to about 1985, and there are estimates that at this point 95% of classrooms have an overhead projector. They are just everywhere. It's not like an optional thing. They are just assumed.
A sort of fascinating thing about these devices is they have more complicated success around the world, for a lot of really simple reasons actually. One is that electrical cables were different, so it was hard to sort of mass-produce these things in that way. Another one is that paper sizes are different in certain places. So this is very clearly designed to show you sort of a normal 8 and a half by 11 piece of paper. You go elsewhere and normal letterhead paper is not the same size. And the idea of, okay, I'm going to have to completely retool this thing, redo literally like the optical science of it in order to satisfy a different size, made this complicated. They were still huge lots of places, but it wasn't quite as ubiquitous immediately in exactly the same way.
But even at that moment, even at peak overhead projector, they are only an education tool. Like I've done a lot of research. This has been studied many times for many years. They never really became anything other than an education tool. Like you go back to your guy with a briefcase overhead projector, that just never happened. It just never panned out.
Where are you imagining the overhead projector popping up? Like, do you want one in your living room?
This is going to be my question to you.
I'm sorry. I'm sorry to steal it. I mean, honestly, if I had one of these at home, I absolutely would have played games on this thing. This would have been fun. There's some sort of analog Pong to be played here.
Yeah. I mean, and there's a lot of...
That's just called tennis. That exists.
I'm not going outside. Antero, do you have any brilliant ideas of where we could have put overhead projectors 40 years ago?
I mean, I think, Jake, to your point, I will give a shout-out to a collaborator I work with closely, Matthew Berland. He's a professor at Madison, University of Wisconsin-Madison, and he and I, we do game design-related things in education and have been thinking about overhead projectors and transparencies as a game mechanic, right? Like, what is the way that you can think of the transparency as an overlay to think through the changing of environments? You see a lot of this in tabletop role-playing game spaces, Dungeons and Dragons, right? In the ways that that kind of space functions pretty well, right? So you think of all of the actual play podcasts that have kind of created a resurgence in tabletop gaming practices. The overhead projector is totally ripe for that kind of space, right? So instead of people looking down at a table, you could project it and kind of change those kinds of spaces.
I'm completely nostalgic for these as devices and would love to have one in my living room. And I think I have seven-year-old twin daughters who are running around the house, and they would have a blast with one of these things, right? I think kids would have a ball playing with an overhead projector. Or they would think it's the most boring thing ever, depending on how you frame this. It's because they don't know the power in controlling one. We have that legacy.
This actually gets to maybe the next thing we should talk about, which is that kind of right about at this point, overhead projectors slowly start to die. And I say slowly because they lingered a very long time. They are in many cases still around, but the idea of overhead projectors as kind of the default best technology in the classroom begins to kind of seep away. And Antero, I spent a lot of time looking this up, trying to figure out what killed overhead projectors.
And there are a lot of possibilities.
And maybe the answer is just all of them. But as you look back, do you have a hypothesis as to what killed...
I think if they have kind of near-ubiquitous saturation by the mid-80s, right? That this is the time when you get VHS and cassette tapes, right?
You get video as the large part of this, and then by the late 80s, early 90s, you get the computer room in the school, right? Like you get the room where kids go to engage with content, right? So you get these two things that I think are different kinds of ed-tech solutionist approaches to quote-unquote fixing schools that are happening at the same time. So you know, the thing that was once the overhead projector now becomes the thing I was talking about earlier, right? The TV on the cart that gets rolled from classroom to classroom and you get to watch movies on it. And then you get kids moving to the computers rather than the computers moving to them a couple decades later. I think those are the things that start filtering us out, right? Filtering the overhead projector out in some ways.
And again, also reconfigures and redesigns how classroom spaces are used, right? The TV does the same kind of thing, but you oftentimes do need to turn off the lights, right? So you're no longer looking at the teacher. You're looking at a screen without the teacher next to it. And then the teacher has to turn on the light when they want to pause the tape or whatever it is at the time. And then for the engagement with computers in the computer lab, you had to either go to the back of the classroom if you had maybe one computer in the back of the classroom, or your whole class had to get up, take their stuff, go somewhere else, maybe have to pair up depending on the size of the computer lab, right, at a given school, and go to that space, right? Like we're constantly thinking through how do we negotiate getting kids in front of a different device, a different kind of learning opportunity versus, I think, the versatility of the overhead projector.
Yeah, that's a good theory. And the thing I found myself wondering through all of that is whether actually what we should have had is all of those things coexisting, because I think all the things you just described actually serve very different purposes, right? Especially when computers were a place in the school and not just a thing you had at your desk, what you accomplish in the computer lab or the computer in the back of the class is very different from what you can do with an overhead projector versus what you can do with a video. And it just seems like, and they all did coexist for some period of time, but it feels like these things were beginning to replace again this kind of education that maybe the overhead projector belongs more to the history of blackboard and chalkboard and it ends with this and it turns into something else rather than this being sort of a new technology that is more like a screen. I actually think this might be more like the chalkboard. But I don't know, like could these things have all peacefully coexisted in classrooms forever?
I think so. I think this gets us to the dreaded smartboard in some ways, right? Like that is kind of the closest I think equivalent of the thing that's interactive and displaying some kind of information onto a screen that people can do stuff with if they'd like to. And so you see responses to it. You see engagement with it. There's something to be said of all of these kinds of coexisting. Whether or not they actually help young people, I think, is probably the bigger question, right? Like the amount of money that was made off of overhead projectors and the amount of money that's made off of laptops, right? And how much of that went to training and supporting teachers and young people is the thing I continually wonder about today.
Yeah, absolutely. Jake, what do you think? I do think that these things should still exist in a lot of ways, right? The ability to put something up on screen very quickly and to change what you're showing on the fly. I feel like that really breaks down when you get into the digital world, right?
There you go. And that's beautiful and that's wonderful. And you know, can you refresh it real quick? Can we...
But this is the thing, right? Like once you introduce computers, even in a world where people are pretty computer-savvy, man, it takes me a while if I'm doing a Google presentation to change from one tab that I'm displaying to another tab that I'm displaying, and I have to re-enable permissions every five days for whatever reason. And that's a lot of work for me as somebody who is pretty tech-savvy. And I just cannot imagine a world where every single teacher is going to effectively use those things. Whereas any teacher could just print out a few sheets of exactly what they wanted and use them for years. I don't know that this necessarily needs to still exist, the overhead projector, but something with this level of ease feels essential for a classroom. And this is why I think smartboards are such a scourge on humanity because they promised to be that and replaced a bunch of other things in service of being that and were just never, ever, ever, ever that for one minute for anyone.
Once you've got to do dongles, it's all over.
Yeah. It didn't work. They broke all the time. They caused all kinds of problems. Like there is something so powerful about the fact that I can just always do that. Like I can just sit here and I can just write. There is a 70% chance that if I had just tried to do that on a smartboard, something would have gone wrong.
I do like that the main, I think the main company name for the smartboard was the Promethean board, right? And in some ways the overhead projector looks like you're both kind of sitting around a campfire in some ways, like it's got the kind of toasty energy of it, feels like it.
So knowing that this is a completely impossible question to answer because this is a field of study that never ends, do you think this particular version of education, right, what we've talked about with the way that teachers turned around, the way that teachers and students started to interact, this new paradigm for what a classroom could look like that I think you can give the overhead projector a lot of credit or blame, whichever you choose, for doing, was that sort of the start of a new movement in how we think about education, or was it just a thing built around a specific technology and then we changed for a new technology?
I mean, I will say, so as I mentioned, the overhead projector was a part of my schooling experience until I graduated, and then by the time I became a teacher, was on its way out. And so I'll offer a couple of dates, and I'll age myself here. So I graduated in 2000, and I became a teacher in 2005 or six, right? I think I student taught in five, became a teacher in 2006. And so in that six-year period, the overhead projector had kind of seen its end of days at that point. And as a result, during that period, the world of public education in America went through some radical shifts at that same time, right? In the early 2000s, under the Bush administration, we had No Child Left Behind, and we had the kind of deep, swift pendulum swing towards high-stakes assessment and what that looks like. And in some ways, I wonder if that reorienting, and then we also had, you know, the move towards one-to-one devices that happens closer to 2010, 2012. We have the introduction of the iPhone and then the smart devices that are happening at the end, right? So you can kind of think through the kinds of ways that educational technology, the kinds of ways that platforms of learning systems and LMSs and all of what that looks like are rapidly transforming what happens in classrooms.
And the ubiquity of like those candy-colored Apple computers at the time. I can't remember, were they? Is that what they were at the time?
The iMacs and the eMacs. Yeah.
That's right. Yeah. So, like you have all of these different kinds of pieces competing for people's attention. They are brighter, glossier, and in some ways much sexier than what this device looks like. This is the industrial nature of the 3M OP, right? Its days are numbered at this point. Yeah. And so just to name, right, that the convergence of educational policy and the rise of educational technology as guiding educational policy, I think, are what really kind of pushed this device out and allowed user-licensed products to kind of reign supreme.
