Serial Learning A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Applying the theories of empiricist philosophers, Ebbinghaus maintained that serial

Serial LearningA B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Applying the theories of empiricist philosophers, Ebbinghaus maintained that serial lists were learned by associating each item with the item that directly followed it:

Ebbinghaus’ Associative Theory

A B C D EThese connections between adjacent items are called direct associations. They form because of “temporal contiguity”: Adjacent items “touch” in time. Each time the list is practiced, the associations between these contiguous items are strengthened.



A B C D E

Ebbinghaus discovered that associations also form between non-adjacent items. He called these remote associations.


Remote associations are weaker than direct associations. After saying A, you have a stronger tendency to say B than to say C.


A B C D E

Remote associations cause errors early in practice. With more practice trials, direct associations gain more strength than remote associations.


The greater the time gap between two items, the weaker will be the remote association between them.


A B C D E

For example, suppose each item appeared for 5 seconds.

5 5 5 5 5


A and D are separated by 10 seconds whereas A and C are separated by 5 seconds. The remote association between A and D will be weaker.


A B C D E5 5 5 5 5


Ebbinghaus demonstrated remote associations using his “Method of Derived Lists”. He would learn a list of 16 nonsense syllables on one day and then the next day he would learn a second list derived from the first.

Method of Derived Lists

The second list consisted of the same 16 nonsense syllables as the first but in a different order. It was constructed by taking Item 1 from the original list and then skipping over 1, 2, or 3 of the next items to get Item 2 for the derived list.



“Skipping by Ones” (1st-Order Derived List)

1, 3, 5, 7, 9, 11, 13, 15, 2, 4, 6, 8, 1 0, 12, 14, 16

Note that in the original list, remote associations theoretically existed between these items. This should speed up the relearning of the list.



“Skipping by Twos” (2nd-Order Derived List)

1, 4, 7, 10, 13, 16, 2, 5, 8, 11, 14, 3, 6, 9, 12, 15

The remote associations linking these items should be weaker than those in the 1st-order list because the 2nd-order items were originally separated by a longer time gap. Relearning should be slower than with the 1st-order list.



“Skipping by Threes” (3rd-Order Derived List)1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15, 4, 8, 12, 16

Relearning should be slowest because these items theoretically have the weakest remote associations.



For comparison, Ebbinghaus also tested himself on the original list, a reversed list (16, 15, 14, ...) and a scrambled (random) list.



The results support the theory. Interestingly, the reversed list was second fastest, indicating that direct backward associations are even stronger than the remote associations.

ResultsFastest Relearning

Slowest Relearning

Original List

Reversed

Skipping Ones

Skipping Twos

Skipping Threes

Scrambled


The Serial Position Curve

When subjects learn a serial list, they usually show a pattern of errors in which items in the middle of the list are missed on more trials than items at the beginning or end of the list. When this pattern is studied on a graph, it is called the “Serial Position Curve”. For many years, researchers have tried to understand the processes responsible for the serial position curve. Both associative and cognitive processes appear to play a role.



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Serial Position of Item

Suppose that subjects practice a list of nonsense syllables until they can recite it without an error. For each subject, we count how many times each item was missed across all of the trials. We take an average for the group to get a measure of the typical error pattern. We set up the graph like this...



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Technically, the peak is a little past the middle of the list.



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...and the beginning of the curve has fewer errors than the end.



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But the basic problem is to explain why the most errors occur around the middle.


The Role of Remote Associations

A B C D E

Visually, there appears to be a relationship between the pattern of remote associations and the pattern of errors when learning a serial list.

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A B C D E

Researchers focused on “spanning associations”: remote associations that span a direct association. There are more spanning associations in the middle than at the ends of the list.

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3 5 35



A B C D E

Concepts were borrowed from classical conditioning to explain why spanning associations interfered with the formation of direct associations. The Lepley-Hull Hypothesis applied the concept of inhibition.

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3 5 35


These efforts to apply conditioning concepts ran into roadblocks; key predictions were not supported.


Confidence decreased in the basic Ebbinghaus view of serial learning: that we associate each item with the next automatically as the result of the time schedule on which the items were presented.


The Role of Strategies

The associative theory leaves out peoples’ strategies for learning. Maybe subjects miss more items in the middle because they first try to learn the items at the beginning and end. These items stand out more; they get more attention. The end items can serve as anchors to which subjects can later attach the middle items.

Cognitive theory has long emphasized subjects’ strategies for learning, how subjects modify the conditions of practice arranged by the researcher.



Glanzer and Dolinsky (1965) demonstrated that they could control subjects’ anchoring strategy, and that this strategy affects the shape of the serial position curve.

They presented a list of 10 nonsense syllables for 40 trials, 2 seconds per item.

They used a closed-loop or continuous presentation procedure in which there was no rest period between the end of one trial and the beginning of the next:

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1...



The Control Group was told that the first syllable they would see was the “beginning” of the list and the 5th syllable was the “middle”.

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 B MThe Experimental Group was told that the first syllable they would see was the “middle” of the list and the 5th syllable was the “beginning”.1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 M B



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1 10Serial Position of Item

Serial Position Curves

The Control Group showed a standard curve, with the fewest errors around the instructed beginning and the most errors around the instructed middle.



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The Experimental Group showed an upside down curve that reflected the unusual instructions they received. The fewest errors were on Item 5, the instructed beginning. There were many more errors on Item 1, the instructed middle.



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Formation of Response Units

Karl Lashley argued that well-learned sequences, like playing notes on a piano, are performed too fast to be the result of item-to-item associations. Individual elements are run off as a single unit.When you recite the alphabet, you may group certain letters, like LMNOP, and run those off like lightning, then pause before going to the next group.


Formation of Response Units

William K. Estes suggested that each response unit was represented by a code, and these codes were arranged in a hierarchy. To perform a serial task, you think first of the highest level code, like “alphabet”. That triggers a lower level code, like “beginning”. Then that triggers the code representing “first group”:

ABCDEFG

which triggers the code for “second group”:HIJK

Hierarchies of codes reflect the cognitive emphasis on relational learning and organization in memory.

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Serial Learning A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Applying the theories of empiricist philosophers, Ebbinghaus maintained that serial