learning the ropes

To improve the interaction quality when entering characters into the stitch memory of the Bernina 145, I propose additional functionality for the existing “A” button. The sewing machine currently jumps to the “A” character when the “A” button is pressed. Nothing happens currently if the “A” button is pressed repeatedly.

I propose that pressing the “A” button will cycle among three commonly used “jump points” in the list of characters: “A”, “0″, and “_”. I believe this will accelerate text entry because it will allow the current character “cursor” to jump quickly in a list of 59 characters. (As an aside… I have to wonder why there are only 59 characters in the list. Why not one of the 2^n numbers?)

Tomorrow evening I will film my user interaction test using the software prototype I developed this evening. It would be very easy to get carried away with making a realistic mockup of the Bernina, but I did my best to stick to the bare
essentials.

I asked my wife to operate the paper prototype. When I shot the video, I had her enter the whole string. This was torturous for her — and I had her do it twice: first without the improved process and then with it.

I learned several important lessons from constructing the prototype and from her subsequent testing with it:
- It is important to cleary communicate the desired operation. In our first testing session, we forgot to use the Alpha button to jump back to the beginning of the alphabet.

- It is worthwhile to think through (or even mockup) the interaction before building the prototype. I had devised what I believed to be a clever system for scrolling through the numbers on my prototype which involved pulling a long tape of the characters through a window on the paper control panel. It was a clever idea, but it didn’t take into account the spatial orientation of the paper control panel. I had a mental model of horizontal scrolling in my head when vertical scrolling would have been much better for this application. When I discovered this flaw, I had already produced a full version of the prototype and was reluctant to fix it. As as result, it was difficult to pull the numbers horizontally past my wife’s hand without bunching them up.

Analysis
The time spent operating the prototype and then subsequently editing and uploading the videos was substantial. Although I have videos of both interactions, I have only posted the first test. Notating this interaction is quite unwieldy. After consulting with Amit, a more useful test would have been to concentrate my efforts on analyzing the part of the interaction that was particularly frustrating: having to scroll through the entire character set to get to the “.” character. Amit suggested that I could have focused simply on entering “N.S” and notating that.

I edited the process of entering “[AT]SERVER.COM” out of the video I’ve posted above and as a further extension could even edit out everything except the “N.S” of from “JOHN.SMITH”. Qualitatively, I do feel that the improvement I’ve suggested will make a big difference — especially for long strings. My wife mentioned that she doesn’t usually use the machine’s memory for long strings because they take so long to enter — and it can be difficult to remember the characters she has already entered.

Today I’m going to learn to sew… so I thought it would be most important to be able to write letters with the sewing machine. Since I’ll soon be creating garments for myself, it would be very useful to sew my email address in them, in the event I lose them.

Description
My wife’s Bernina 145 Sewing Computer is very well designed and extremely usable. I had never tried to operate it before and found that I could navigate its controls without opening the instruction manual. I even figured out that the Bernina 145 can stitch simple alphanumeric characters into fabric. My wife has found that the interface for entering characters into the stitching memory is pretty weak. As I’ll demonstrate in the videos of the operation, it takes many button presses to navigate through the character set. I believe the character-entry process could be improved without even adding any buttons to the control panel.

The initial operation I began testing was entering “JACK.SMITH[AT]SERVER.COM” into the machine’s memory.

The following video documents my attempt to complete this operation.

Analysis
It turns out that notating and evaluating this particular operation is a greater level of committment than I had anticipated. There are many, many button presses. There are also a number of ways to complete the entry

I created a quick demo program to explore the slider behavior, where quick=1.5 hours. I found a library in Processing to do the slider, but I had trouble getting it to work quickly.

(more…)

Objective: Change the selected voice to “DreamRodes”
Assumptions: TG77 already in VOICE mode and on MEMORY I (internal). (1)

Notation (2):
[Button]
\ – Press
/ – Release
* – Number of repeats
s – Number of seconds

Ex: [Y \ /]*52 / 10s

I have produced short movie clips illustrating each of the ways to select a new voice

(1) This assumption is made to constrain the number of possible ways to change the voice. Without these assumptions, it would be necessary to consider many other paths from different modes. This study would be useful in the evaluation of the ease of use of the Yamaha TG77 in live performance. In live performance environments it is crucial to be able to switch quickly between the most important modes related to the performance.

(2) I considered an XML-based notation format, as I thought it might be useful later on to have the format easily machine-parseable. It seems from first glance that there is a heirarchy of presses and releases. By nesting presses, it is easy to see what happened and when.

<Yes/><Yes/>
<Yes>
<Left/>
</Yes>


This is likely overkill, so I’ll abandon it for now.

I have two suggestions related to voice selection on the TG77:
1. Implementation of a “jog wheel” function in order to scroll through the voice names at variables speeds
2. Implementation of a “search” function to locate the voice without having to scroll through the various banks

“Jog Wheel”
Interestingly, the TG77′s keyboard-counterpart (the Yamaha SY77) has a rotary wheel control which can be used to scroll through voices. I wonder why the designers didn’t do this for the TG77 using the DATA ENTRY slider.

The video below shows the mocked-up jog wheel operation. The DATA ENTRY slider on the TG77 doesn’t have a function when the unit is in Voice Display mode, so I feel this would be a logical use for it. I mocked up the interaction by holding down the “+1/YES” button while moving the slider.

Notation:
[Slider /] / 3s [Slider /] / 2s = 2 operations / 5s

Notes:
This interaction raises several interesting questions.
1. How quickly should the slider move through the voices? A rotary knob with detents has an implied mapping: 1 voice per click. The slider has no detents.
2. What happens if the slider is at the top of its range when the user wants to jog through the voices? The answer to this question is related to how we answer #1… This probably is an area that requires some user testing. Unless moving the slider back down a bit will allow access to the full remaining range of voices, this could
be very frustrating to use. The data entry slider on my Studio Logic SL-1100 behaves a bit like this — and can be frustrating.

Voice Search
In Voice Display Mode, only two of the function buttons are used (F7 and F8). Another button (F6) could be used as a “Search” button. Pressing “F6″ would cause a search dialog box to appear. I think dialogs are beyond the scope of this assignment.

Test 5: Selecting the “DreamRodes” voice by direct numeric entry

When the DreamRodes is selected in Voice display mode, the upper left portion of the screen displays “VOICE-I D05(53)”, which translates to “Voice Mode, Internal Bank – D, patch number 53″. Using this knowledge, we can jump immediately to the DreamRodes any time we have the Internal memory bank selected.

Buttons:
“5″ – [5]
“3″ – [3]
“Enter” – [E]

Notation:
[5 \ /]*1 / 0.5s [3 \ /]*1 / 0.5s [E \ /]*1 / 0.5s = 3 operations / 1.5s

Quality:
If you know the number of the voice you’re selecting, this is the way to go. It requires the least number of operations in the least amount of time. The downside is that it requires what Donald Norman refers to as “knowledge in your head” of a system. You must already know the voice number corresponding to DreamRodes.

Notes:
I assigned short durations to these button presses as they are located close to one another.

Test 4: Selecting the “DreamRodes” voice by using the voice directory

Buttons:
“F8″, to be abbreviated [F8]
“Bank/Select”, to be abbreviated [Bank]
“Right Arrow”, to be abbreviated [>]

Notation:
[F8 \ /] / 1s [Bank \ /]*2 / 2s [> \ /]*1 / 1s = 4 operations / 4s
Quality: It is much easier to find a voice when you can see a bunch of them at a time. The downside of this method is that you must be close to the face of the unit in order to read the names.

Notes:
When the TG77 is in Voice Display mode

the F8 button displays a list of the voices.

Test 3: Selecting the “DreamRodes” voice by pressing and release the “+1/YES” button in cycles

Buttons: “+1/YES”, to be abbreviated [+1]

Notation: ( [+1 \ ] / 1.5s [+1 /] ) * 12 = 24 operations / 18s

Quality: This seems better than simply holding down the “+1″ button if you’re looking for a particular instrument.

Test 2: Selecting the “DreamRodes” voice by holding down the “+1/YES” button

Buttons: “+1/YES”, to be abbreviated [+1]

Notation: [+1 \]*1 / 7s [+1 /]*1 / 0s [-1 \ /]*1 / 1s = 3 operations / 8s

Quality: It is very easy to overshoot the desired voice while holding down the “+1″ button. This technique is not recommended if you don’t remember the name of the instrument you’re looking for.