Fig.1. Screenshot
showing main page of sandstone tutorial.
About the
Tutorial
Development History
The current version of “Sandstone Petrology: A
Tutorial Petrographic Image Atlas” is the
product of three funding periods. Nine months
of support from the College of Natural Sciences
at the University of Texas at Austin (2000-2001)
allowed Ph.D. student Suk-Joo Choh, in
collaboration with the P.I.s, to create a
collection of about 90 mapped images focused on
grain identification. DUE-CCLI granted a
one-year proof-of-concept project (commenced
June 2001) that focused on formal educational
assessment of an expanded (300-image) tutorial.
The product of that funding period was published
by AAPG as version 1.0 in 2002. Finally, a DUE-CCLI
‘full development’ project began in January of
2003 and will continue until January of 2006.
Fig.2. Screenshot
of an image showing information on the main grain.
Educational Approach and Philosophy
The principal educational approach of the
tutorial is an interactive “virtual” microscope
experience using a non-intrusive user interface.
A key element of the tutorial is that the
petrographic images fill a substantial portion
of the available screen area (approximately 96 %
of 800 by 600 pixels used). Each image, as in a
true microscope view, is unadorned until the
student actively calls up information that is
temporarily displayed over the image. In
passing the cursor over the image with the
mouse, the cursor appears as either an arrow or
a hand. Areas of the image where the pointing
hand appears are scripted such that clicking on
the region calls up either a small amount of
text that identifies the feature displayed
beneath the cursor, or a larger box of text that
expounds upon the key conceptual information
conveyed by the image (Fig. 2). On clicking
again, text boxes disappear and the student can
continue to explore the image or move to
another.
The tutorial presents
to the student a somewhat neutral or passive
“persona”. There is no directed path, through
the information, for example. The student is not
told “learn this first”, or “memorize these
three things”. At most, the relative
‘importance’ of things is indicated passively,
by position and repetition. It should be clear
to the students that classification, imparting
the organization of the entire tutorial, is a ‘1st
level’ order of business. Quartz cement images,
feldspar diagenesis images, and compaction
images, far outnumber those of zeolite cements
and heavy minerals, leaving an impression that
is in keeping with the actual practical
importance of understanding these different
aspects of sandstones.
The greatest bulk of the tutorial’s
informational content is actually hidden from
view. In effect, the student is forced to
engage the tutorial as an active learner (or,
alternatively, choose to log out). In using the
tutorial students must continually ask questions
and make decisions. “What is this?” is the
overarching question throughout the 500+ images.
“How do we know?” and “Why isn’t it something
else?” are constant supporting themes. The
‘reward’ for having asked the question is
receiving the answer. Having received the answer
to one question, the student must then decide
where to go to ask the next question---elsewhere
on the same image, to the info box, or, to the
next image, glossary, tutorial, etc. The
tutorial is sufficiently richly endowed with
answers that a student can persist in
exploration for a long time.
Through combined active learning and repetition
the student is able to encounter, absorb, and
organize a large amount of complex visual
information. Because the medium on which the
information is recorded is highly portable, the
student can engage this material flexibly and,
we hope, far more often than is possible with a
single laboratory exercise or lecture.
It is interesting to note that over the six
semesters we have evaluated the tutorial, NOT
ONCE has a student issued a complaint suggesting
the tutorial content is too large, too
repetitive, or too difficult to access. Rather,
a common complaint has been that the images are
inadequately mapped. The students request more
clickable areas in each image. They are, in
essence, wanting to ask more questions and get
more answers!
