Abstract:
The essence of this research was to study the differences in problem-solving
ability achieved from Conventional and from Investigative Laboratory instruction. The
researcher believed that the investigative laboratory approach would yield higher problemsolving
abilities than the Conventional one. In order to prove this hypothesis, the researcher
designed experimental research with 46 technical College students comprising a controll and
an experimental group. Both groups were assigned to study the same contextual information
in the different experimental methodologies.
The development of these two laboratory types was an essential task for the study.
The sheets were constructed from the same contextual information using different
experimental strategies. Using investigative content criteria, laboratory sheets currently used
in the region were surveyed. Three content topics, namely, characteristic of R and L, Polarity
testing and Vector grouping of a transformer, were found form three laboratory sheets. The
surveyed Laboratories were slightly modified to suit the research purpose and were treated as
the conventional experiment in the controll group. With the same contextual information, three
investigative laboratories were developed. Task analyses were performed, and sets of situation
were created to provide an investigative process. Observation sheets were also constructed to
measure the practical performance. Laboratory and observation sheets were unanimously
approved by five content experts.
A test-set employing principles of situation creation and questioning techniques
was developed to evaluate the problem-solving perfonnance. Four problem-solving steps
including problem-sensing, hypolhesis setting, hypolhesis verifying and solution concluding
were employed in the development. The test comprised 84 question items developed from 21
situations. Eight situations with 32 question items were used for pre-test and 52 questions
from II situations were used for post test. From item analysis, the tests were found to have
lhe following average indexes: 0.57 difficulty, 0.36 discrimination, 0.75 reliability. The tests
,
were primarily used in classifying students learning achievements: high, moderate, low and
later in determining the students problem-solving abilities after learning from the laboratory.
The laboratory sheets and lhe tests developed were used with two randomly
assigned groups of student. A controll group of 22 students was placed to work wilh the
three conventional laboratories. The experimental group of 24 students worked with the three
investigative laboratories. Observation using observation sheets was made every 10 minutes to
monitor lhe perfonnance of instrument handling, problem-solving abilities and experimental
procedures.
The post-test was conducted with both contrail and experimental groups. Scores
were collected and calculated using SPSS statistical analysis. Overall, it was found that the
investigative experiment yielded higher problem-solving abilities (p < 0.05) than the
conventional one. As a hypothesis set, the study showed a statistical significant difference. In
detailed study, the scores comparing among the three classified levels indicated that the low
achievment students received better improvement than the olher two. No significant difference
in the improvement was found in other areas. However, the observation revealed the fact
that lhe investigative laboratory process created more enlhusiasm in team working and more
discovery learning.