Introduction - Human-Computer Interaction - page 6

than 75 % and up to 91 % of the time. Commenting, underlining and highlighting a
document during reading supports better understanding, critical thinking as well as
remembering the thoughts the reader had. Adler et al. call this process Active read-
ing [2]. As Adler notes, “the physical act of writing, with your own hand, brings
words and sentences more sharply before your mind and preserves them better in
your memory”. Annotations and notes are not only central to reading but also im-
portant for efficiently attending meetings or lectures. Psychological research shows
that notetaking plays an important role in learning processes and has been proven to
be a factor positively related to students' academic achievement [58, 115].
An important affordance of paper documents is that they can be easily annotated.
Handwritten annotations can consist of lines and brackets that highlight portions of
the document. They can also contain text, formulae, sketches, etc. This shows their
great fluidity in form [92]. They can be very informal or more structured, for exam-
ple if the user follows a specific annotation or notetaking method (e.g. the Cornell
Notetaking Method [113]). Moreover, handwritten annotations on a printed docu-
ment are clearly separated from the document. Finally, several persons can annotate
the same copy of a document [131].
People make most of their annotations on paper, even when the document is
available in a digital version [131, 153]. The results of field studies that we have
conducted to inform our work show that university students clearly preferred printed
versions of lecture scripts to their digital counterparts, mainly for ease of annotation
[145]. The results also show that using a pen and paper handouts in a seminar results
in a higher number of annotations than using a tool for typewritten annotations on
a laptop [143, p.28 sqq.]. Similar in approach, Obendorf [109] compared paper-
based annotation with annotations made on Web pages. He found that in the paper
condition much more annotations were made.
Yet, these results do not imply that handwritten annotations are in all cases prefer-
able to typewritten ones. Pen and paper are clearly beneficial for quick and implicit
annotations that are tightly interwoven with reading. In contrast, typewritten anno-
tations might be advantageous as soon as the annotation is made less implicitly, is
longer and formulated with more care. Think for instance of formulating a summary
of a topic chapter. The point is that in the latter case, the annotation process can be
considered as related rather to composition than to reading.
Pen-enabled displays emulate many of the characteristics of pen and paper. This
poses the question whether they are as good as paper for making handwritten annota-
tions. Empirical studies come to differing results. There is some empirical evidence
that the use of pen-enabled displays generates greater extraneous cognitive load than
the more familiar interactions with real paper [112]. Morris et al. [99] report quali-
tative findings indicating that pen-enabled horizontal and tablet displays provide an
annotation experience largely comparable to pen and paper. However, the partici-
pants were still suffering from difficulties stemming from the annotation software,
such as the overhead of entering a special inking mode. Piper and Hollan [116]
compared handwritten annotations on paper and on horizontal displays that were
tinguish between annotating and notetaking because on a technical level, handwritten notes can be
modeled as annotations on an empty document.