Lectures: Problems for Students
and Teachers
Our reliance on lectures is the most glaring example
of the problems plaguing education. Lectures are so
futile that I would feel foolish describing their
inadequacies if they were not so pervasive. Everyone
recognizes the basic lecture model: a teacher stands at
the front of the room, while students sit quietly taking
notes. At university there is no attempt to disguise
this model. With enrollment for some classes in the
hundreds, there is little chance to do much else. A walk
through the halls of any high school will confirm that
lecturing is the predominant model there as well.
The biggest problem with lectures is that
they are inherently ineffective because they involve
groups. Students bring to class different backgrounds,
experiences, interests, and aptitudes. It is impossible
to meet the optimal learning pace of all students
because one teacher cannot deliver dozens of customized
lessons simultaneously.
Teachers do their best by teaching to the “middle of
the class”. But in trying to meet the needs of all
students, they meet the needs of few. Slower students
are left behind, while faster students are left
twiddling their thumbs. The time of both groups is
wasted. However, this is a simplistic analysis. Students
are not so neatly sorted into slow learners and fast
learners. In reality, each student finds certain topics
easier, relative to the rest of the class. There are
three layers of student differences: general student
ability, specific topic ability, and the
minutetominute variations in a student’s focus.
Together, these make it impossible for lectures to meet
the optimal learning pace of all students at all times.
Some people talk in their sleep. Lecturers talk
while other people sleep.
– Albert Camus
If you had 8:00 AM lectures in university, as I did,
you know that there is not much learning going on if you
are tired – or at home in bed. Students frequently miss
class. Conversely, a student cannot be absent from an
audiotape, videotape, book, or computer program since
these media reveal their content only when a student is
ready to learn. Even students who attend class can miss
critical ideas when their focus fades. We’ve all had our
attention diverted in a meeting or lecture. Our mind
wanders to relationship problems, what to eat for lunch,
or the names of the Seven Dwarfs. If we lose focus while
reading a book or viewing a video, we need only
backtrack or rewind to regain our place. However, since
lectures travel in only one temporal direction, students
can miss critical concepts and remain lost. (In case you
were wondering: Bashful, Doc, Dopey, Grumpy, Happy,
Sleepy, and Sneezy.)
Another reason lectures are inefficient is that they
are spontaneous. Lectures are not scripted, rehearsed,
and edited like books, videos, and software. In writing
this book, I have made countless edits – deleting
sentences, paragraphs, and even entire chapters because
they were redundant, unimportant, or misleading.
Lectures contain pauses, inaccuracies, backtracking, and
unnecessary embellishments that contribute to their
inefficiency. But scripting lectures is not the
solution.
If lectures were scripted, besides being more
accurate and seriously boring, they would remain
inefficient. Our brains can process information faster
than we can vocalize it. Researchers in the somewhat
bizarre field of “timecompressed speech” routinely
shrink audio recordings to 50% without any decrease in
comprehension (savings are achieved by deleting pauses
and speeding playback). Similar improvements can be
achieved by replacing audio with text.
The ear cannot skim in the temporal domain the way
the eyes can browse in the spatial domain.
– Barry Arons
High school students can read twice as fast as
teachers speak. On average, teachers lecture at 111 words per
minute (plus 17 wpm from students, for a total of 128
wpm). Videotaped lectures, created as instructional
aids, also typically have rates near 125 wpm.
Conversely, average silent reading rates are 205 wpm in
ninth grade and 250 wpm in twelfth grade. Even higher
rates can be achieved, albeit with reduced
comprehension, when text is scanned or skimmed. This is
an indispensable strategy. Readers constantly make
adjustments depending on their familiarity with a topic,
the difficulty of a passage, and their reasons for
reading. Listeners cannot make similar adjustments to
slow or hasten live speech.
Another factor that contributes to the inefficiency
of lectures is notetaking. Although
lectures proceed at 125 wpm, students can only copy
notes at 20 wpm. To accommodate notetaking, most of what
a teacher says cannot be worth recording; otherwise,
students would not be able to keep up. Teachers must
incorporate enough embellishment, redundancy, and waste
to ensure that 20 written words can summarize 125 spoken
words. By this measure, lectures that allow notetaking
have a theoretical maximal efficiency of 16% (20 wpm ÷
125 wpm).
The true level of efficiency – whatever it is –
cannot be very high since students who skip lectures
suffer no ill effects when given instructor’s notes.
This was the finding of one classic experiment. Groups
of students viewed a 20minute lecture – one group took
notes while another group listened. A third group did
not attend the lecture at all. Two days later, all
students were given 25 minutes to study from a set of
instructor’s notes before taking a test. Scores were the
same, regardless of whether students had attended the
lecture. In other words, the original lecture had been a
complete waste of time.
Another study, with a similar protocol, arrived at
the same conclusion with a 30minute lecture followed
one week later by a 15minute review of instructor’s
notes. Once again, the lecture was a complete waste of
time. The authors concluded, “The present data raise a
question about the function of the lecture itself. Since
students who did not attend performed as well as those
who did … the lecture per se may be a redundant vehicle
for communicating substantive information.”
next:
Problems with Grades
This is an excerpt
from
Chalkbored.
Order the book
here
to learn more about ...
 Time in school versus time spent learning
 The role of classroom questions (from students
and teachers)
 What research reveals about the effectiveness of
notetaking
 Alternatives to lectures: discovery
learning, cooperative learning, and individualized
instruction
