Design a Drawing Machine

I named my exhibit prototype "Design a Drawing Machine" because I wanted the title to evoke the fact that the user is actively engaged in building the machine by selecting which gears and types of arms.

Challenges of Prototype Creation:

I made a lot of changes from my last prototype to this first iteration on the exhibit floor. One of my primary focuses was on enhancing user experience: color coding gears by even/odd/prime, sliding magnets, a way to color code and match up the handle/knob to the dowel, and more (thinking of affordances from the Exploratorium article we read.) Changes I made included:

• Neodymium magnets and rubber band tension system: I designed an easy way to add and remove different sized gears by sliding the center dowels. The original challenge was that weding in the wooden dowels took too much effort and precision and was not at all intuitive or easy for the user. (This magnet band set-up took a lot of tricky tinkering and testing to set up, and still, I found out through testing on Friday that this needs to be improved)
• Better construction of the harmonogram base, including a handle for the left hand to grip and exert downward pressure with (U-bolt)
• Additional progress: color-coding and labeling gears based on # of teeth: blue is even, gray is odd, orange is prime.
• Constructing 5 different arm types (scissor, single, uneven lengths, long, short)
• A stand to carry the removable and exchangeable parts

A problem I still had after I finished the prototype was slippage: because the rubber band magnet system only exerts the right pressure when certain gear sizes are paired up, often the gears would slip over each other, or slip away so that contact is lost. While I solved the problem of easily switching out gears by creating a new mechanism for doing so, I created a new problem in the process, which was gear slippage. I tried to mitigate this issue by adding a sign and label that suggested gear ratios / gear sizes for the exhibit user to test out. These gear pairings were selected so that it would stretch the rubber bands just the right amount to hold everything tightly in place without creating too much slippage pressure. Of course, I later learned that no one reads signs.

Experience on the Exploratorium floor:

I had a very illuminating experience on the Exploratorium floor. My most pleasant surprise was the kids were actively engaged in the harmonograms and spent a few minutes with the exhibit; there were many people who spent over 5 minutes tinkering with the same drawing machine. Knowing that most people spend less than a minute at a given exhibit, I was pleasantly surprised. I think the drawing aspect of the exhibit makes it hands-on and engaging for the kids. 

I was also happy with the parental interaction with kids. Often times the parents did a great job of encouraging the child to use the machine correctly "Look, there's a 'turn this' label on this handle. You should turn here." But several times the parents themselves also didn't quite get the interaction correct in terms of which hand goes where and how to set up the machine. I think this was my fault as the designer not putting sufficient cues or diagrams to help. 

I was also very pleasantly surprised by the collaboration between kids. I heard one kid tell the other, "If you have a bigger gear it helps" or "Put that gear here." Even though these kids were elementary school students, they were still thinking critically and helping each other out.

"Pile on all the things!" I noted that none of the kids under middle school level set-up the machine correctly; I realized kids have a tendency to want to pile on as many things as possible onto a machine, when given spare parts to choose from, in this case, gears and arms. Of course, these machines didn't draw the curves, let alone budge at all. However, I noticed kids were happy just to have drawn some scribbles on paper. It seems kids like 2 things: making marks (with pen, pencil) and chaos.

Other problems I noted:

• Gear slippage when too much pressure was put in turning the gears. Usually kids would react to this gear slippage by cranking it even harder. This, of course, does not help.
• The other visitors were more calm and steady, but there was still gear slippage from time to time. More often than not they were still applying too much pressure.
• Girls were more patient.
• Older visitors are more patient. When one of the kids patiently set up the machine and made it work, I deliberately asked for his age: 8th grade.
• People didn't know how to hold the machine. Many people tried turning it with both hands when in fact 1 hand was easier. Some would hold no handles. I should make the affordances better for this aka make 1 handle look like a knob and the other one shorter
• People didn't set up the arms correctly. They would set the arms in the enter dowel, which of course doesn't move the arm at all. I should have a diagram to help guide users.
• No one reads signs
• No one reads labels. Even the labels that were directly on the machines were ignored such as "Turn this" or "hold here." Sometimes the parents would notice that let the kid know, but more often that not they were completely overlooked.
• Because of the abundance of gears and arms to switch out (many degrees of freedom) I noticed that the users were spending a lot of time playing with gears, and not much time actually cranking the machine to produce the end resulting curve. In my next iteration I might want to have less variability and less chaos.
• A lot of users benefited from seeing someone else do it correctly first so at several points during the afternoon I would pretend to use one of the machines as if another Exploratorium visitor, and since there were 2 harmonograms, I hoped others would step in and try to mimic my motions

Many many many scribbles and the result of a kid putting 3 arms on 1 harmonogram

I think a lot of my experiences reflected what Alice said about how "people are not as intelligent as you think." For instance, they would continue to turn the gear even after the gears had slipped and it was clear the turning had no effect. But perhaps I should give them credit and say instead, "people are not me." As the creator, I know where to put the arms, which knobs to hold, and exactly what pressure I should crank the gears so that it doesn't cause them to slip.

Visitors' interactions with classmates' exhibits:

What I noticed for most of the exhibits is that kids like swarming. They swarm around an exhibit 5-7 kids at a time, which results in interesting side-effects, such as in Winnie's case, kids sometimes blocking the light source. Kids also love using exhibits in an unintended, often dangerous way, as I noticed when they picked up the lasers from Dan's exhibit and started pointing them at each other's faces. 

Changes and improvements based on my experience on the floor:

My plan for the final iteration is twofold:

• First, I want to redesign the machine so that instead of slots and sliding magnets, I have discrete holes that securely hold the rod in place. Instead of 3 moveable gears, I will have the center gear set in place, since that one is just to move the other 2 gears in a ratio and its own size has no significance. This way, with 1 gear anchored, it is easy to create discrete, tight fitting holes for the other gear sizes on either end. I hope this will solve the problem of gear slippage and simply make it more intuitive to use.
• Next, I want to improve affordances by making handles were necessary and color coordinating where each item goes (ie. match the yellow-marked rod with the yellow hole.) I will also have a large diagram of what the final set-up looks like, and what a user looks like when cranking the machine (like the "magic want" diagram)

The beginning

The aftermath