App Inventor's blocks-based programming language lowers barriers for specifying the behavior of mobile apps. However, while simple App Inventor blocks programs are easy to read and write, more complex ones can become overwhelming. Creating, modifying, and navigating nontrivial blocks programs is tedious, and snippets of blocks programs are not easy to reuse between projects or share between programmers.
To address these issues, members of Wellesley's TinkerBlocks research group
have been exploring the idea of integrating a text-based notation for App Inventor's blocks into App Inventor.
Back in 2014, Karishma Chadha (then a Wellesley senior) developed a prototype feature for
App Inventor that allowed users to convert clusters of blocks to code blocks containing
TAIL, a text-based version of the blocks. You can read about TAIL and code blocks in
this summary or
Karishma's undergraduate thesis.
This was an early example of dual-mode environments that integrate blocks
and text, but TAIL never made it beyond the prototype stage.
In 2019, Wellesley student Qianqian Huang rose to the challenge of continuing the development
of a text-based language for App Inventor. Majoring in both Cognitive and Linguistic Sciences
and Computer Science, her goal is to develop Venbrace, a text-based notation for App Inventor
that is both learnable and usable. The design of Venbrace is guided by a set of design principles
that you can read about in this summary. Qianqian worked on the first version of Venbrace for her May 2020 senior honors thesis.
A key design principle of Venbrace is evidence-based programming language design,
which dictates that the language design process needs to be an iterative one that
interleaves language design and implementation with user studies that evaluate the effects of different language design decisions on learnability and usability.
The Venbrace Syntax Study is the first user study involving Venbrace. The goal of this
study is to determine which aspects of the preliminary design of Venbrace are easy/hard
for App Inventor programmers to learn and use, and to get feedback from them about their
preferences for alternative notational choices being considered.
The study is conducted entirely online and is estimated to take 90 minutes
of focused attention to complete. Once they start the study, subjects can spread
work on the study over a 24-hour period to allow for breaks.
Participants will first need to agree to an online consent form; if they are less than 18 years old,
they will also need to obtain consent from a parent or guardian.
The study begins with a pre-survey form that asks for general information about the subject
and their familiarity with App Inventor and any other programming languages they might know.
(No knowledge of any languages beyond App Inventor is expected.)
Subjects will then learn (through video tutorials and online documentation) how to
translate App Inventor blocks programs into the Venbrace text language.
The learnability of Venbrace will be evaluated in numerous tasks that
ask them to write short Venbrace programs that correspond to App Inventor blocks
or to determine which Venbrace programs are valid translations of particular blocks.
They will also be asked for their preferences in translating some blocks
we haven't yet decided how to translate.
The study concludes with a post-survey that asks subjects to reflect on
what they learned in the study.
A $20 electronic Amazon gift card will be provided to every subject who
completes the entire study, provided that the researchers judge that the subject
has made a serious attempt to answer all the questions in a meaningful way (no gibberish for answers).
The electronic gift card will be emailed to the subject within 48 hours of completing
the study. All subjects in the first round of the study received the $20 gift card.
The first round of this study was held in late April, 2020. Since then, we have been improving the
Venbrace language and the study based on what we learned from the first round of the study.
The second round of the online study will be conducted from Fri. June 26 through Fri. July 3.
(This is much later than the early June time frame we originally predicted.
Improvements to the language and study based on the first round took
longer than anticipated.)
Subjects can take the study during any 24-hour period during this week.
Any high school student (including recent high school graduates) familiar with App Inventor can participate in the second round
of the study, as long as you did *not* participate in the first round.
We are planning a Round 3 version of the study that will start around July 15.
You can participate in at most one round of the study.
If you're interested in participating in this study, please fill out
this Google form and we'll email you about how to start the study when it is ready.
If you have any questions about the study, email us atVenbrace: A New Text Language for App Inventor
The Venbrace Syntax Study
Want to Be a Participant in the Study?
venbrace-syntax-study@wellesley.edu
To protect your privacy, please (1) email us from the same email account you use to sign in to App Inventor
and (2) do *not* tell us your name.
The TinkerBlocks Team
Developing the online Venbrace Syntax Study has required a tremendous amount of effort.
In addition to Qianqian, the other current members of the TinkerBlocks team helped
with various aspects of the study: