Sweet（1899/1964），representative of associationism，interprets language learning in terms of the associationism of his time：

The psychological foundation of the practical study of languages is the great law of association to which we have frequently had occasion to allude already.

‘The whole process or learning a language is one of forming associations.When we learn our own language we associate words and sentences with thoughts，ideas，actions，events’（op.cit.102）.‘The function of grammar is...to sum up the associations by which we all understand and speak our own language as well as any foreign languages we may learn’（op.cit.：103）.From these observations，Sweet derived a few general principles of associative learning：（1）‘Present the most frequent and necessary elements first’；（2）‘Present like and like together’；（3）‘Contrast like with unlike till all sense of effort in the transition ceases’；（4）‘Let the associations be as definite as possible’；（5）‘Let the associations be direct and concrete，not indirect and abstract’；（6）‘Avoid conflicting associations’.Sweet emphasized the need for repetition and memorization，but with economy and always on good grounds and without facile tricks.

Harold Palmer，even more than Sweet，was strongly conscious of the psychological component in a language teaching theory.He，too，considered the learner factor as much as the learning process.In his analysis of the learner he weighed up the importance of age，temperament，the student's motivation and academic background，such as his previous experience in language study and his general level of schooling，and more doubtfully his nationality.Palmer thus arrived at a definition of language aptitude as a composite of different elements：‘the student of even temperament，an expert penman，an artist in mimicry，an expert in the linguistic，pedagogic，and mnemonic sciences，unspoiled by previous defective study and possessing a powerful incentive，is more likely to study a foreign language with success than one who is his antithesis in every particular.’（1917/1968：33）.

In Palmer's view（1922/1964），the language learning process had a natural basis in man's‘spontaneous capacities for acquiring speech.’Nevertheless，this had to be combined with the use of‘studial capacities’，i.e.，deliberate，cognitive，co-operative learning.Palmer was firmly convinced that the learning processes most appropriate for language learning are those that lead to habit formation and‘automatic’，unconscious use rather than those that lead to concept formation and systematic thought.The chapter‘Habit-forming and Habit-adapting’in The Principles of Language Study（1922/1964）is perhaps one of the most eloquent statements of this point of view ever composed：‘Language learning，’Palmer writes，‘like all other arts as contrasted’with sciences，is a habit-forming process.Proficiency in the understanding of the structure of a language is attained by treating subject as a science by studying the theory，but proficiency in the use of a language can only come as a result of perfectly formed habits.No foreign word，form，or combination of these is“known”or“mastered”until we can use it automatically，until we can attach it to its meaning without conscious analysis，until we can produce it without hesitation and conscious synthesis.’（1964-54）He counters the possible objections to an automatic habit theory by these observations：‘The fear of monotonous and tedious memorizing work，and the realization of the length of time necessary for each act of memorizing，induces the student to invent pretexts for avoiding such work，it declares that“parrot-work”is not education，that modern educationalists condemn“learning by rote”，that the age of blind repetition is over and that the age of intelligent understanding has taken its place.

The laws of association directly influenced the study of learning.There is no better example of this than the work of Hermann Ebbinghaus（1850-1909）.According to Ebbinghaus（1885/1964），the study of the development of an association between two mental events could best be accomplished by using stimuli that were devoid of all prior associations（otherwise，one's assessment or measurement of the development of a new association would be confused with，or impeded by，the presence of already-existing-associations）.In some of his studies，therefore，Ebbinghaus used so-called nonsense syllables，which he believed had no inherent meaning.Ebbinghaus spent many hours associating one stimulus with another，and then reciting them back.In doing so，he put many of the principles of association，developed over a century earlier，to a direct test.For example，he determined whether stimuli that were written close together on the list would be more firmly associated than syllables that were not close together.Ebbinghaus's research confirmed many of the ideas first proposed by the British Empiricists.For instance，forward associations are stronger than backward ones（if syllable“A”precedes syllable“B”，then“A”evokes the memory of“B”more easily than“B”evokes the memory of“A”）.

Research on the development of associations was also advanced by the Russian physiologist Ivan Pavlov（1849-1936）.As is well-known，Pavlov（1927）demonstrated that dogs associate the clicking sound of a metronome with food，such that，after repeated presentations of the two stimuli，the metronome itself elicits the salivation response that originally had been triggered only by the food.Pavlov argued that the two events—the biologically neutral stimulus（metronome）and the biologically powerful stimulus（food）—had become associated.Like Ebbinghaus，Pavlov was really putting the laws of association to a test.Indeed，Pavlov's work launched the study of the associative learning process in modern times.

The other person identified as an innovator and pioneer in modern learning theory is E.L.Thorndike（1874-1949）.Thorndike's（1898）contribution was in the area of instrumental conditioning.In his original studies conducted with cats，a subject was placed in a cage containing a lever.In the process of trying to get out of the box，the cat—inadvertently at first—hit the lever，at which point，the door sprang open，and the animal was allowed to eat some food placed nearby.Thorndike then repeated the process，discovering that over the course of training，the cat became progressively better at escaping from the box.It learned to press the lever in a speedy and efficient manner，presumably through a process of reward.

Philosophers have，for centuries，speculated about the origins of knowledge.Greek philosophers set the stage by claiming that knowledge either is innate（Plato）or is derived from experience（Aristotle）.Rene Descartes advocated a duality between mind and body，the former being an unextended or formless reality and representing reason and intellect（which was possessed by humans alone）.A third historical antecedent to the study of learning processes was the work of the British Empiricists，who claimed that knowledge is derived from experience exclusively（the empiricist position）.To describe how knowledge was created，the Empiricists formulated the laws of association，which included the laws of similarity，contiguity，and cause and effect.These laws described the means by which ideas become associated，and they were tested by various pioneers in learning research，including Ebbinghause，Pavlov，and Thorndike.

Association also plays a key role in the concept of learning developed by Edwin R.Guthrie（1886-1959）.Guthrie's principle of contiguity—that is，“association through closeness”—was both simple and direct.He said that once a stimulus and a response become associated，a recurrence of that stimulus will tend to be followed by the same response.Pavlov criticized Guthrie，saying that he was insufficiently concerned about the complex factors conditioning，but Guthrie replied by saying that Pavlov was studying a highly artificial form of learning，one that could，in any event，be explained by Guthrie's simpler and more general principle of learning.Indeed，Guthrie believed that any of the complex forms of learning，such as those found in the classroom，could be explained in terms of principles derived logically from his one simple law of learning.