Download Designing Interactive Query Interfaces to Teach Database Systems

Work-in-Progress
CHI 2015, Crossings, Seoul, Korea
Designing Interactive Query
Interfaces to Teach Database
Systems in the Classroom
Lilong Jiang
The Ohio State University
Columbus, OH USA
[email protected]
Arnab Nandi
The Ohio State University
Columbus, OH USA
[email protected]
Abstract
Database systems have often been considered an
unexciting topic for undergraduate curricula. To remedy
this, we describe a novel interactive electronic textbook
for teaching undergraduate database systems courses.
Designed for touch-driven tablets, the textbook embeds a
fully capable database. Expressions, figures and
explanations in the textbook are live, interactive elements.
In contrast to canned illustrations and animations,
students can interact with each textbook element. The
rapid feedback loop with the database allows the user to
explore and understand the full scope of valid and invalid
queries to the database. Wireless connectivity allows the
instructor to track classroom performance in real-time,
merging textbook instruction with in-class demonstrations,
allowing for the scaling out of classrooms. We discuss the
design of this concept, and share a preliminary evaluation
of a prototype implementation used in the classroom.
Author Keywords
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CHI’15 Extended Abstracts, April 18–23, 2015, Seoul, Republic of Korea.
ACM 978-1-4503-3146-3/15/04.
http://dx.doi.org/10.1145/2702613.2732900
databases; education; touch; interaction
ACM Classification Keywords
H.5.m [Information interfaces and presentation]:
Miscellaneous.
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Figure 1: Interactive Textbook
Prototype on the iPad
CHI 2015, Crossings, Seoul, Korea
Introduction
Focus: Relational Algebra
With the proliferation of data-driven processes in all walks
of life, the ability to use, create and manipulate databases
has become a necessary and important skill. Database
education is needed at several levels – end-users are often
unaware of the language to use to interact with the
database. Users – both students and data practitioners –
may also be unaware of the schema, i.e. organization of
the database, or the data itself. In such cases, educational
material about databases is a valuable tool, both from an
educator’s and practitioner’s standpoint. Technologies
that aid end-users with databases are highly valuable both
from an educator’s and practitioner’s standpoint [2].
As a start, we focus on relational algebra, a typically
hard-to-teach topic in databases. All elements of the text,
e.g., formulae, figures, and long-form explanations are
interactive and connect with a live database. For example,
to explore the projection operation, tapping on one or
more attributes of a relation generates a new projection,
with the corresponding expression being rewritten in the
text (Fig. 1 shows a prototype of this). Unlike canned
animations with exactly one outcome, the user can try all
possible combinations and internalize the principles of the
projection operator.
Interactive Features
Given the ubiquity of computationally powerful smart
phones and tablets amongst students in today’s
classrooms, we envision a modern interactive electronic
textbook (ebook) that embeds a feature-rich database
directly into the ebook itself. Unlike traditional ebooks
with animated figures and popups, the textbook is a live
database that can be experimented with. For each
component, our focus is on interacting with fundamentals
and the data, allowing the user to intuit and internalize
the concepts, instead of learning by rote.
In this paper, we describe the design considerations of an
interactive textbook built in the context of undergraduate
database curriculum at Ohio State. While prior work in
pedagogy using “clickers” [5], interactive control [4, 6]
and Read-Eval-Print Loops (REPLs) [1] have focused on
basic polls, math, and programming languages – applying
it to database education is a compelling opportunity. This
interactivity blurs the lines between textbook instructions
and in-class exercises, and allows students to appreciate
topics without requiring the tedious configuration or
background instruction.
The interactive features and user interface are illustrated
in Figure 2. Each page in the book covers a different
algebra operator, and is divided into two parts: the left
part introduces a specific relational algebra operator, while
the right part demonstrates the operator.
Interactive Querying
We build upon ideas from the direct manipulation-based
Gestural Query Language [3], allowing for intuitive and
user-friendly querying using touch cues. The desired
features of an ideal query language include the direct
manipulation, closure and composition, feedback, and
expressivity. Specifically, users are able to perform queries
directly with gestures on the relation and once the query
is specified, the animation feedback will show how the
query result is generated. As mentioned previously in an
example, a projection query can be specified by tapping
on one or more attributes. Once specified, the expression
will be updated to show the current specified query. Then,
the selected attributes will be highlighted and then moved
into the result area.
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Reactive Text
There are two types of reactive text in our document.
One is used to explain the concept. For example, if users
tap the “unary operation” reactive text, it will pop up a
dialog to give an explanation of this concept. The other is
used to represent a query, and when tapped, will trigger
an execution over the sample data. Conversely, any
interaction with the sample data changes the text to
reflect the query, derived using Query-By-Example
heuristics. For example, when users tap the reactive text
of a query representation, the system will automatically
issue this query and walk through the query to show how
the query result is generated. If the user queries directly
over the relation, the reactive text will be changed
accordingly.
will see the first selected attribute being included in the
result set, followed by the second selected attribute, giving
insight into the composability of projection operators.
Relational Sandbox
algebraic expression
 Name, Age ( Name = Anna (PEOPLE))
Anna
29
Figure 3: Relational Sandbox
student usage
))
instructor)
insights)
touch-driven
interactive
queries
embedded
relational
database
reactive text step-through controls results
algebraic expression
Figure 2: Direct Manipulation and Interactive Querying
Step-by-step Querying
In order to allow the student to revisit each step of the
explanation, we provide a slider so that the student can
control the animated query sequence and learn each
operation at their own pace. For example, two attributes
are selected in Figure 2, when users move the slider, they
A relational sandbox is provided as the last page of ebook,
where the student is shown a relation, and they can
subset any part of that relation using touch actions, and
the ebook will construct a sample relational expression for
them based on the highlighted values, if possible. Figure 3
gives an example where a valid algebra expression is
constructed according to the highlighted values.
Real-time Analysis of Class Participation
The network connectivity of the devices provides a novel
opportunity for the instructor to gain real-time insights
into usage. Since the ebook is in fact a web application,
each student’s touch actions can be tracked from a
central location, allowing for the instructor to have a
real-time dashboard of in-class performance during the
class itself. While similar ideas in interactive clickers [5]
have been investigated, the insights here can be far more
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fine-grained, and do not require any extra action on the
student’s part.
Preliminary Results
As a first step, we have prototyped a chapter on relational
algebra, a typically hard-to-teach topic in databases. The
system is implemented as a HTML / Javascript
application with a backend written in python.
In order to test whether our ebook helps users understand
the relational algebra better, we performed an in-class
study. We asked 24 students to use ebook to learn
relational algebra, and conducted a post-class survey. For
each relational algebra operator, we asked the students
whether the ebook helped them understand the concept.
As shown in Table 1, most students think the ebook helps
them understand the relational algebra operators better.
Conclusion
We introduce a novel blend of a textbook and an
interactive database query interface that aids students to
understand relational algebra. The ebook allows students
to issue queries interactively, observe the query process,
and grasp a better understanding of the underlying
database concepts. Preliminary survey results from an
in-class trial of a prototype show that most students think
the interactive textbook will help them understand
relational algebra. Going forward, there are still several
challenges that are needed to be addressed. For example,
allowing users to input the relational algebra expression
and observe the query results is a highly desirable feature.
Additionally, expanding the relational algebra into other
database concepts, for example SQL, is an ideal next step.
Acknowledgements
This work was supported in part by the National Science
Foundation under CAREER award IIS-1453582.
Table 1: Ebook Survey
Operator
Very Helpful
Neutral
Not Helpful
Projection
Selection
Rename
Union
Intersection
Difference
Cartesian Product
Inner Join
Outer Join
Sum
Count
Average
Max
Min
18
20
19
16
18
15
16
12
14
18
21
18
20
19
6
4
4
8
6
9
8
11
8
5
2
5
3
4
0
0
1
0
0
0
0
1
2
1
1
1
1
1
References
[1] McDirmid, S. Usable Live Programming. SPLASH
Onward! (2013).
[2] Nandi, A. Breathing life into database textbooks.
CIDR (2015).
[3] Nandi, A., Jiang, L., and Mandel, M. Gestural Query
Specification. VLDB (2014).
[4] Papert, S. Mindstorms: Children, Computers, and
Powerful Ideas. Basic Books, Inc. (1980).
[5] Schell, J., Lukoff, B., and Mazur, E. Catalyzing
Learner Engagement Using Cutting-Edge Classroom
Response Systems in Higher Ed. CTHE (2013).
[6] Victor, B. Learnable Programming. Worrydream.com
(2012).
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