Transcript Overview of Long

Overview of Long-Term Memory
laura leventhal
Reference
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Chapter 14
Learning and LTM
The major task of learning new material
is to integrate it into the existing
structure of information that is already in
LTM.
 Rehearsal is useful to retaining
information in STM and Working
Memory
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• LTM requires rehearsal and integration
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Integrated information in LTM is
Features of LTM
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LTM is permanent memory (as opposed to
STM or working memory)
LTM has essentially infinite capacity. It is an
open question whether people ever truly
forget information that is stored in LTM.
LTM has slower access compared to STM
• 1/10th of a second vs. 70 ms
Features of LTM (2)
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Information gets into LTM from STM, via rehearsal Getting information
out of LTM is called retrieval. Information can be in two ways, recall or
recognition.
In recall, information to be retrieved from LTM must first be found and
then recalled. In recognition, an informational cue is provided and the
information retrieved is matched against the presented cue.
Designer Lesson
• Generally recall is more difficult than recognition. You will probably
remember that in our discussion of interaction styles, we mentioned
that menus may be easier for novices to use as compared to
command line interactions. Why - with menus, all options are
presented explicitly, so selecting a menu option involves
recognition. When using command line interactions, generating a
command involves recall.
Information can be accessed in
different ways
LTM stores different sorts of information
 Information can be retrieved or
accessed in different ways
 For example
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• people have excellent recognition memory
("I always remember a face", deja vu) -but
may do less with at retrieving linguistic
label (name)
Types of knowledge in LTM
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Information in LTM is organized into two types of knowledge:
declarative knowledge and procedural knowledge.
Declarative knowledge or knowledge of facts indicates "knowing
what". An example of declarative knowledge is knowing the
answer to the following question "what is the capital of Ohio?"
Declarative knowledge is easy to communicate
Procedural knowledge is knowing how to do". In general,
procedural knowledge may be more difficult to communicate.
Designer Lesson
In some of our recent work, we have used dual presentations of
text and visuals to convey procedural information. In particular,
virtual reality presentations seem to be quite effective in
presenting this type of information.
Representation of Knowledge
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Knowledge is organized 1] hierarchically (represents
categories), 2] temporally (represents sequences)
and in 3] networks (represents complex connections).
Both the information and its organization changes
over time. We observe that the organization of
information in LTM supports our memories of
episodic: events to experiences in temporal order.
An expert has developed a complex, multi-level body
of knowledge in their domain of expertise, stored in
LTM.
Representation of Knowledge (2)
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Some knowledge is semantic or about meaning. Semantic knowledge is
knowledge of general concepts, independent of a specific situations. For
example, an expert programmer understands the concept of array regardless of
the programming language.
Some knowledge is syntactic or about surface structure. Syntactic knowledge is
also stored in LTM, but it is more detailed than semantic knowledge and is less
(cognitively) structured. Knowing the format of the C++ while structure is an
example of syntactic knowledge. Syntactic knowledge is more easily forgotten
than semantic knowledge.
Semantic knowledge is acquired through demanding and meaningful problemsolving.
Syntactic knowledge is acquired by rote. The acquisition of new syntactic
information may interfere with previously-learned syntactic knowledge or vice
versa. Hence, programmers often have much difficulty learning a second
programming language.
There are vast individual differences in the quality and capabilities of building
informational structures in LTM. Also children and adults differ. Adults have an
existing informational structure. Their challenge is to integrate new concepts
into the existing structure. .Children on the other hand are building their DB so
much of what they do is concept learning and formation.
Designer Lesson Even within a narrow group, ability to integrate new concepts
will vary tremendously.
Learning - construction of
knowledge
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Learning is a key focus of cognitive psychology and
has been the subject of many studies and
experiments.
Here is a short summary about learning.
• Learning is the process of building knowledge; this may
involve the formation of concepts.
• Learning is complex.
• Learners are not passive absorbers of information.
• Learning involves the integration of new information and
experiences with our existing structures.
• What we learn may be wrong.
• We learn by rehearsal, doing, vivid experiences and through
analogies.
Learning - Designer Lessons
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Research in HCI has suggested that people
learn to use computer systems most
effectively if learning is active..
• Consider having users engage in actual interface
tasks not long bouts of manual reading. Active
learning may also be enhanced if user makes
errors and receives useful feedback.
• Set goals where action sequence is obvious.
• Use analogies
Skill Acquisition
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Some CHI activities involve skill acquisition or use of
skill rather than complex knowledge. There are many
“laws” of human factors that one can use in design.
These generally apply to sensory-motor skills rather
than knowledge.
For example, the power law of skill acquisition
suggests that our improvement is fast at first then
much slower. When you learn to do something, like
use a mouse, you improve quickly at first..
Subsequent improvements take longer. The more
that you practice, the faster that you get though.
The power law states that task time on the nth trial
Tn = T1n-.4 where n is a constant for task