A Research of the Influences of Verbal Guidance On
Chemical
technique
e-mail:lsxywx@sina.com
Many researches on cognitive athletic psychology have shown that characterization of speech can promote the explicitness degree of athletic skills (1-4). For instance, Shea’s study has shown that during the learning period of athletic skills, coaches or gym teachers can help the athletes or students to maintain their athletic skills and keep the accuracy of explicitness through proper Verbal information (1). The experimental researches by Chen Min and Zhou Tianbao (1998) show that applying Verbal drilling to physical education (i.e., making the students repeat aloud the name of the motion during the training) can help to improve the motor skill and maintain the results (2).
In Vygotsky’s viewpoint on the
influence of speech on personal behavior (in terms of both recognition and
motor), one’s adjustment of behavior is, in a high degree, a process of speech,
which is continuously developing from social speech to internal speech.
Individual behaviors are initially adjusted by speech from others, and are then
adjusted by the speech instructed by the
learners themselves, and at last, they are automatically adjusted by the
internal speech transferred from the self-instructed speech. External
adjustment from others, self-adjustment and automatic adjustment, consist the
3-stage skill acquisition theory of Vygotsky.
Utilizing this theory, Shen and Xin
(1998) designed the teaching experiment, which are very effective for improving
the teachers’ ability of teaching supervision (5). Though Vygotsky’s theory is
mainly about the intellectual skills acquisition (6), since the study of chemical technique contains the study of rules
(operation procedure, methods), i.e., the study of intelligent skills, we still
believe it is instructive to the study of chemical technique. It is clear from the chemical education
literature that some sort of mental preparation combined with physical practice
can benefit students’ laboratory skills. (?)
Inspired by the aforesaid researches, we believe that Verbal instructions (including Verbal guidance from others, self-instruction of the learners and internal Verbal guidance) is also helpful for the forming of operation skills of chemical experiments as delicate motion skills. However, we still need to make clear if Verbal guidance is effective for the forming of operation skills of chemical experiments.
The purpose of the study is to design instructive experiments according to the assumption that Verbal guidance is helpful to the forming of chemical technique, neutralization titration as the task of experimental operation, study the influence of Verbal guidance on chemical technique, and to provide psychological basis for the teaching quality of chemical technique of students.
The basic assumption of the study is: applying Verbal guidance to the study of chemical technique (i.e., first make the students operate corresponding experiments under instruction of teachers while learning the procedure, methods and precautions of experiments, and then repeat the aforesaid knowledge aloud while operating corresponding experiments independently, and at last ask the students to repeat the aforesaid knowledge silently while operating corresponding experiments independently) can stimulate the students to transfer external Verbal guidance into internal Verbal guidance, i.e., forming the internal instructing procedure of operations, so as to improve the accuracy of experimental operations and the effect of automatization.
2 Methods of research
2 .1Testees
142 students from three classes of grade 2005 (High school grade 1) from of Panxi high school, age 15-16, the testees have learned theoretical knowledge about neutralization titration while have not observed and operated neutralization titration experiments.
2.2 Test design
The 142 students are divided in 2
groups according to odd and even student numbers (numbered randomly when the
students are enrolled), and randomly define the
experimental group (Verbal guidance group) and
the control group (non-Verbal guidance group), adopting post-test of the experimental group and the control group.
2 Test materials
This study is reviewed from two aspects: correctness of experimental operations of the testees and the time required to complete the experiment.
Experiment review task: titer the NaOH solution with unknown concentration by HCl solution. Chemicals, instruments etc. for the experiments shall be prepared in advance.
See table 1 for details about review items, standard operation procedure and rules of grading.
Timers for the experiments adopt stopwatches used for track events.
Table 1, Record card for chemical technique review
|
Laboratory Practice and standard of grade |
Lost score |
Time spent |
|
|
1. Washing
conical beaker |
Washing method(2 score) Washing times and
water volume every time(2 score) |
|
|
|
2. Washing burette |
Solution volume used to wash
burette every time (2 score) Washing times (2 score) Washing method (2 score) |
|
|
|
3. Acid added to acid burette |
Add to acid solution (2 score) Exhaust bubble (3 score) Adjust liquid level under zero scale (3 score) Read scale of liquid level (3 score) |
|
|
|
4. Base added to base burette |
Add to base solution (2 score) Exhaust bubble (3 score) Adjust liquid level under zero scale (3 score) Read scale of liquid level (3 score) |
|
|
|
5.measuring 20ml NaOH solution |
Add to NaOH solution(3 score) Whether position of glass beading is moved (3 score) Read scale of liquid level (3 score) add to phenolphthalein and shake up(3 score) |
|
|
|
6.titration |
Put a white paper under conical beaker (1 score) Titration (3 score) Sway conical
beaker (3
score) titration before end-point (3 score) observe end-point(3 score) Read scale of liquid level (3 score) |
|
|
|
total |
|
|
|
2. 4
Testers
To
control the testers’ prejudice during the experiments, we’ve taken the four
measures as follows: Do not notify the testers of the purpose of the study; ask
the testers to be sure of the purpose, operation procedure, methods and
precautions etc. of the neutralization titration; before the test, organize the
testers to carry out detailed analysis on the review items and grading
standards of the test, e.g., “bottle shaking” operation in “titration” can be
segmented into: correct and skillful operation, 3 scores; basically correct
operation, 2 scores; partially wrong operation, 1 score; completely wrong
operation, 0 score.; organize the testers to carry out simulating tests on 2 “testees”
based on the aforesaid 3 steps to unify the measurement.
2. 5 Testing
procedure
To make the students participate in the tests earnestly so as to get
genuine conditions of the test, tasks and test review record cards are handed
over to the testees 2 days in advance, and the students are notified that: “the
result of this test will be counted in the total grades of the semester by 10%.”
To eliminate the learning effect of the non-Verbal guidance group from the
Verbal guidance group and the mutual learning between the students, the test
will be completed in 6 hours; the non-Verbal guidance group was tested before
the non-Verbal guidance group; during the test, the students that have been
tested should be isolated. 5 testers (chemistry teachers of high schools)
should test 10 tested each time. The testers’ task is to: observe the process
of the experimental operation of the testees, record the results of observation
item by item according to the experiment review record card, and at the same
time record the total time to complete the experiment. Before the test, the
same teacher should first explain to the testees the operation procedure, methods
and precautions of the neutralization titration while demonstration, then the
testees shall practice for 3 times before finally participating in the test. In
the specific operation, the experimental group (the Verbal guidance group): in
the first practice, the testees operate corresponding experiments under the
testers’ Verbal guidance while learning the procedure,
methods and precautions of experiments and other knowledge of recognition, in the 2nd
practice, they are asked to repeat aloud the above knowledge while operating
corresponding experiments, and finally, they are asked to repeat silently the
above knowledge while operating corresponding experiments. The time is 30
minutes. Control group: the testees practice for 3 times within the same time.
Finally, the tested data are coordinated and analyzed with social science
statistical software package SSPS10.0.
3 Results and discussion
3. 1 Results
See
Table 2 for the results of the testees’ correctness of experimental operations.
Table 2
Results of the testees’ correctness of experimental operations.
|
|
n |
M |
SD
|
t |
|
Control group |
56 |
55.75 |
2.62 |
-2.621* |
|
Experiment group |
56 |
56.82 |
1.57 |
|
* P<0.01
The
results have shown that: in term of correctness of operation, Verbal guidance group is better than non-Verbal guidance
group. The distance between the two groups is very distinct.
See
table 3 for the time required for the testees to complete the experiment
Table 3:
the time required for the testees to complete the experiment
|
|
n |
M |
SD
|
t |
|
Control group |
56 |
9.530 |
1.766 |
3.991** |
|
Experiment group |
56 |
8.218 |
1.714 |
|
** P<0.001 (time unit: Minute)
The
results have shown that: the time required for the
Verbal guidance group to complete the experiment is less that that of the non-Verbal guidance group, the distance between the two
groups is very distinct.
3. 2 Discussion
In term
of correctness of experimental operations, the Verbal
guidance group got higher results than the non-Verbal
guidance group, and the distance between the two groups is very
distinct. This indicates that Verbal guidance can
improve the correctness of the learners operations. Then why Verbal guidance can improve the correctness of the learners
operations?
It is considered that during the study of chemical technique, providing Verbal guidance for the procedure, methods and precautions of experiments. Recognition psychology deems that characterization is the means of information to appear and record in human brains. There are two kinds of characterizations of declarative knowledge, characterization of proposition and characterization of representation. Proposition representation means a kind of network system constructed by the certain concepts kept in long-term memory according to a certain relationship, it has the features as follows: recognition function: it is represented by the of mental association of knowledge; layer characteristic: it is represented by the organization and construction function of the upper layer to the lower layer: Insufficient recognition function: it is represented by that the known knowledge of related objects can be used for thinking and reasoning of the objects to make up the missed value. Therefore, proposition representation system can acquire various useful information relating to the proposition representation by activation and diffusion.
In term
of the time required to complete the experiment, the
Verbal guidance group spent less time that the control group, and the
difference between the two groups were extremely distinct. This shows that:
during the study of chemical technique, Verbal
guidance can improve the automatization degree of the learners’ operation
motions and reduce the time required to complete the experiments. This
has been observed during the process of the test, the
operation of the Verbal guidance group was obviously easier, faster and more consistent
than that of the non-Verbal guidance group,
many testees of the non-Verbal guidance group operated in awkward and
inconsistent motions, some even appeared not to no what to do next and
needed the help of the experiment review record card or operations of others as
clue of further operations.
Why the Verbal guidance group spent less time than the control group? We think that on the basis that the operation motions are
basically correct, the time required to complete the same experiment is related
to the automatization degree of the operator’s motions, the higher degree, the
less time, whereas more time will be needed. While the automatization degree of
motions is related to the forming of the internal instructive procedure in
human brain to instruct the motions. In the viewpoint of recognition psychology,
the mental mechanism of skilled operation motions is the internal instructive procedure
formed in human brain that instructs operation motions (Shao Ruizhen, 1997)(8), which adopts production system characterization. In J.R.
Anderson’s viewpoint, the learning of operation skills is divided into 2
stages: stage 1 is the illustrative stage, i.e., recognition of related
operation skills, mainly the learning of declarative knowledge; the second
stage is the procedure stage, i.e., autoimmunization stage of operation
motions, the process in which that procedure knowledge—internal instructive
procedure is formed. The process in which the operation transfers from
declarative knowledge instruction to the procedure knowledge instruction is
called the knowledge editing. During the learning of chemical technique, making
the students provide the operations with Verbal guidance while practicing can
both strengthen the proposition representation of illustrative knowledge of
related operation motions and accelerate the process of knowledge editing.
In the first practice of the Verbal guidance group, through Verbal
guidance of the procedure, methods and precautions of
experiments,
the teachers can, instruct the learners to pay attention to the proper order of
experimental operations, mark the external clues from the beginning of each
subsidiary motion and correct operations and at the same time carry out
proposition representation and characterization
of representation to preliminarily form the instructive procedure of
experimental operation motions. In the 2nd practice, the students repeat aloud the instructive procedure of the motion during
the training.
The speech in this practice scene have the functions of coordination and
consolidation for the instructive procedure of the
motion formed preliminarily, making them more clearly kept in the learners’ mind; at
the same time, the vocal self-speech again stimulates the senses participating
in the operation, this “self-strengthening” makes the learners further connect
and strengthen the semantic, scenic and nerval and muscular motility information acquired. In the 3rd
practice, the students repeat silently the instructive
procedure of the motion during the training, which is beneficial to the
transfer of operation motions from vocal self-speech adjustment to internal speech adjustment
and can promote the forming of the internal instructive procedure of the
operation motions so as to realize the automation of operation motions.
Therefore, as the automatization degree of the Verbal guidance group was
improved, it is natural that they spent less time than the non-Verbal guidance
group to complete the experiment. Though the non-Verbal guidance group had also
3 practices, since they were lack of clear and systematic Verbal guidance with
from outside to inside, many learners have either fail to form complete
instructive procedure of operation motions (requiring external clues like the
experiment review record card or the operation of other to transfer one motion
to another) or fail to form the internal instructive procedure of the operation
motions (many motions can only be done after a long time of recalling), then it
is natural that then spent more time than the Verbal guidance group to complete
the experiment.
4 Results and suggestions
4. 1 This study has proven the assumption
that during the study of chemical technique, Verbal
guidance can promote the forming of operation skills, i.e., improve the
correctness and automatization of experimental operations.
4. 2 This study can provide experimental
supports to Vygotsky’s 3-stage theory of skill acquisition
in term of the validity of operations in chemical experiments.
4. 3 In teaching chemical experiments,
purposeful Verbal guidance can be utilized to improve
the efficiency for the teaching of chemical technique.
4. 4 The influence of Verbal guidance on the operation skills of learners of
different levels and on the learners’ maintenance of these skills still needs
further study so as to provide more detailed and accurate data for improving
the efficiency for the teaching of chemical technique.
Literature Cited
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2001,3,39—41(in Chinese)
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Min, Zhuo Tianbao, Experimental study of effects of Verbal rehearsal on
movement memory, Journal of Guangzhou Physical Education Institute,
2001,4,59--61(in Chinese)
3. Zhang Liwei, Memory, Cognition and Motor Behavior, Journal of
Beijing University of Physical Education 1991,3,78--83 (in Chinese)
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Technique, J. Chem. Educ.2001, 78, 373-379
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