Sabado, Setyembre 1, 2012

AN INVESTIGATION OF THE CRITICAL THINKING ABILITY OF SECONDARY AGRICULTURE STUDENTS


Journal of Southern Agricultural Education Research 18
Volume 56, Number 1, 2006
AN INVESTIGATION OF THE CRITICAL THINKING ABILITY OF
SECONDARY AGRICULTURE STUDENTS
Scott Burris, Texas Tech University
Bryan L. Garton, University of Missouri

Abstract
The purpose of this study was to examine the relationship between student characteristics
and critical thinking. Additionally, this study sought to determine the unique variance in critical
thinking explained by achievement level. The target population for the study was identified as
secondary agriculture students. As part of a larger study, the sample consisted of 105 secondary
agriculture students purposefully selected based on characteristics of the teacher. Critical
thinking ability was determined by the Watson-Glaser Critical Thinking Appraisal® (WGCTA®)
(Form S). Mean scores for critical thinking indicate that some level of critical thinking is present
in secondary agriculture students. Males and females were similar in their ability to think
critically. Upper classmen outperformed lower classmen on critical thinking. Students
categorized as higher academic achievement levels exhibit higher critical thinking skills than
those students categorized as lower achievement levels. Academic achievement level uniquely
contributed 18 percent of the variance in critical thinking score.

Introduction and Theoretical Framework
Education has long focused on teaching students to give a correct answer. Students often
complete assignments, do well on tests and get good grades; yet, do not learn to think critically
(Brooks & Brooks, 2001). According to Brooks and Brooks (2001), teachers too often ask
students to recite, define, describe, or list facts. Students are less frequently asked to analyze,
infer, connect, synthesize, evaluate, think and rethink. Students have become familiar with this
process of passing knowledge back and forth without inquiring into how this information applies
to the real world (Black & Deci, 2000). The concern over development of critical thinking skills,
or lack there of, has led to a renewed focus of education.
The current educational climate reflects the importance of learning not only content
information, but also developing skills for thinking critically (Pithers & Soden, 2000). The need
for instructional design to improve the thinking process has been substantiated in numerous
reports over the last 25 years (Halpern, 2003). In recent years, more emphasis has been placed in
the student’s ability to understand and use information, not to merely posses it (Richardson,
2003). Furthermore, college faculty identified critical thinking, along with problem solving, as
skills necessary for every college graduate (Diamond, 1997).
While there appears to be unanimous agreement regarding the importance of developing
students’ critical thinking skills, there is much less agreement on exactly what constitutes critical
thinking. The concept of critical thinking was reflected in the teaching of Greek philosophers
such as Socrates, Plato and Aristotle (Burbach, Matkin, & Fritz, 2004; Staib, 2003). Dewey
(1909, 1997) described critical thinking as the suspension of judgment and healthy skepticism.
Multiple descriptions of critical thinking can be found in the literature (Beyer, 1987; Burden &
Byrd, 1994; Ennis, 1962; Halpern, 2003; Pascarella & Terenzini 1991; Simon and Kaplan, 1989;
Stahl & Stahl, 1991). Critical thinking is often linked with, compared to, and used
interchangeably with problem-solving (Dressel & Mayhew, 1954; Facione, 1990; Moore &
Parker, 1994; Pascarella & Terenzini, 1991; Sternberg & Baron, 1985) and higher order thinking
(Burden & Byrd, 1994; Ennis, 1985; Facione, 1990; Whittington, Stup, Bish, & Allen, 1997).
Early efforts of Dressel and Mayhew (1954) established a framework for evaluating
critical thinking. Their work identified five abilities associated with the concept of critical
thinking. Building on the work of Dressel and Mayhew, Watson and Glaser (1994) provided the
following definition:
Critical thinking is a composite of attitudes, knowledge, and skills which includes: (1)
attitudes of inquiry that involve an ability to recognize the existence of problems and an
acceptance of the general need for evidence in support of what is asserted to be true; (2)
knowledge of the nature of valid inferences, abstractions, and generalizations in which
the weight or accuracy of different kinds of evidence are logically determined; and (3)
skills in applying the above attitudes and knowledge. (p. 9)
Consistent with this definition, Watson and Glaser created a data collection instrument to
measure those skills associated with critical thinking. The Watson-Glaser Critical Thinking
Appraisal® (WGCTA®) (1994) measures critical thinking through five abilities: inference,
recognition of assumptions, deduction, interpretation, and evaluation of arguments. Each of the
five abilities is represented by a score on a sub-test of the instrument; and collectively, they
represent an ability to think critically.

A Nation at Risk (National Commission on Excellence in Education, 1983) questioned
the faltering achievement of American students and called for investigations into existing
educational structures. The National Commission on Excellence in Education specifically
identified concerns about students’ lack of ability in critical thinking, higher-order thinking and
problem solving skills. This concern over students’ ability to think critically was further
substantiated by Norris (1985), who indicated that critical thinking was lower than expected in
the United States at every stage of schooling.

The importance of critical thinking has been reinforced by industry expectations. The
Secretary’s Commission on Achieving Necessary Skills (SCANS) (1991) addressed this issue in
their report entitled What Work Requires of Schools. The commission found that high
performance workplaces required competencies in critical thinking. Among those critical
thinking competencies identified were creative thinking, decision making, problem solving, and
reasoning (SCANS, 1991).
Support for the development of critical thinking skills has also been apparent in the
expectations of student performance in public schools. As a result of legislation, the Missouri
Department of Elementary and Secondary Education (DESE)(1996) developed the Show-Me
Standards outlining expectations of secondary students. These standards were a result of Senate
Bill 380, “The Outstanding Schools Act” (1993), which called for the State Board of Education
to adopt performance standards. The Show-Me Performance Standards target the development
of critical thinking skills.
The standards are categorized into four goals. Goal one of the Show-Me Standards
(DESE, 2004) states, “Students in public schools will acquire the knowledge and skills to gather,
analyze, and apply information and ideas”(p. 3). In addition, Goal Three of the Show-Me
Standards posits, “Students in public schools will acquire the knowledge and skills to recognize
and solve problems”(p. 3). Finally, Goal Four asserts, “Students in public schools will acquire
the knowledge and skills to make decisions and act as responsible members of society”(p. 3).
The value of critical thinking skills is evident by the references to analysis, problem solving, and
decision making in three of the four goals.
Critical thinking has been examined through a variety of perspectives. Early studies in
agricultural education sought to identify the critical thinking ability of students enrolled in
secondary agriculture classes. Findings indicated that secondary agriculture students did possess
some ability to think critically (Rollins, 1990, Cano, 1990). Future studies have since
contributed to what Cano initially described in 1990 as a shallow research base.
Studies have explored the relationship between critical thinking and student
characteristics. Torres and Cano (1995) reported that learning style explained significant
variance in critical thinking. In contrast, Rudd, Baker; and Hoover (2000) found no significant
difference in critical thinking by learning style. However, they did find gender to be a significant
contributor to critical thinking disposition. More recently, Meyers and Dyer (2004) found no
difference in student’s disposition to think critically by gender or learning style.
Stronger connections have been made between critical thinking and academic ability.






Rollins (1990) found the best indicator of critical thinking ability in Iowa secondary agriculture
students to be the score on the Iowa Tests of Education Development (ITEDs) reading sub-test,
accounting for 28% of the variance in critical thinking score. Cano and Martinez (1991) reported
a substantial positive relationship between critical thinking and cognitive ability as defined by
the Developing Cognitive Abilities Test. Rickets and Rudd (2005) identified grade point
average, as an indicator of academic performance, as the best known indicator for explaining
critical thinking.
Critical thinking continues to emerge as a primary focus in education. While the body of
literature related to critical thinking continues to grow, there continues to remain disagreement of
factors that are associated with the ability to think critically. One consistent product of previous
studies on critical thinking has been the call for continued investigation.

Purpose and Objectives
The purpose of this study was to examine the relationship between selected student
characteristics and critical thinking. Additionally, this study sought to determine the unique
variance in students’ critical thinking explained by their achievement level. The following
research objectives guided the study.
1. Describe selected characteristics (gender, grade classification, achievement level, and grade
classification) of secondary agriculture students.
2. Explore critical thinking scores according to classifications of gender, grade classification,
and achievement level.
3. Explain the variance in critical thinking score accounted for by achievement level ability
when controlling for differences in gender and grade classification.

Methods and Procedures
Population and Sample
This study was part of a larger investigation and utilized a descriptive correlational
design. While the target population for the study was identified as secondary agriculture
students in Missouri, participants were limited by the design of the larger study. Subjects in the
study were part of a purposive sample. Students were included in the study based on selection
criteria of their agriculture teacher. Twelve teachers were selected based on characteristics of
their teacher preparation program. All selected teachers had been exposed to a similar preservice
departmental philosophy of education, completed similar requirements for teacher
certification, and received similar instruction in teaching methodology. The resulting sample
consisted of 140 students. Achievement score date were unavailable for 35 students resulting in
a usable sample for this study of 105. Due to the limitations of the sampling procedures,
findings from this study are representative of subjects included in the study and should not be
generalized beyond this sample.

Instrumentation
Two data collection instruments were used. Critical thinking ability was determined by
the Watson-Glaser Critical Thinking Appraisal® (WGCTA®) (Form S). The WGCTA® is a
standardized, copyrighted, assessment tool for assessing the success of programs and courses in
developing critical thinking skills (Watson & Glaser, 1994). The instrument includes exercises
which are purported to be examples of problems, statements, arguments and interpretations of
data which are regularly encountered at work as well as at school and in other activities. The
WGCTA® is designed to measure critical thinking as a composite of attitudes, knowledge, and
skills. The instrument is available in parallel forms A and B and is also available in an
abbreviated version (Form S). Form S was used for this study as it is approved for secondary
students and can be completed in approximately 45 minutes.
The reliability of the WGCTA® had been previously established and was detailed in the
test manual. Reliability estimates for Form S of the WGCTA® were reported as a Cronbach’s
alpha coefficient of .81 (r = .81) (Watson & Glaser, 1994). According to Watson and Glaser
(1994), “the content validity of the WGCTA® in classroom and instructional settings may be
examined by noting the extent to which the WGCTA® measures a sample of the specified
objectives of such learning programs. The statewide objectives of public education in Missouri
clearly identify the importance of critical thinking skills as evident by the references to analysis,
problem solving, and decision making. The construct validity of the WGCTA® can be evaluated
by noting its relationship to other tests. Watson and Glaser (1994) report significant
relationships between the WGCTA and test of general intelligence (Otis-Lennon Mental Ability
Tests, the California Test of Mental Maturity, and the Wechsler Adult Intelligence Scale Verbal
IQ).
A second data collection instrument was developed by the researcher. This instrument
was completed by the agriculture teacher and consisted of demographic information (gender and
grade classification) and achievement data. Student achievement was operationally defined as
the score on the 7th grade administration of the science portion of the “Missouri Assessment
Program” (MAP). The MAP is a standardized assessment system developed to evaluate student
proficiency on the state adopted academic standards. The MAP assesses students in
communication arts and science in grades 3, 7, and 10. Mathematics and social studies are tested
in grades 4, 8, and 11. As part of the larger study, teachers reported the score on the science
portion of the MAP as that was the area most related to agriculture. The seventh grade
administration was utilized because it was the most recent administration completed by all
secondary students in the study.

Conclusions and Recommendations
In the study, 35% of the students were female and 65% were male. Data from the
Missouri Department of Elementary and Secondary Education (DESE, 2005) indicate
approximately 30% of students enrolled in secondary agriculture classes for 2003-04 were
female and approximately 70% were male. Therefore, it can be concluded that the sample
approximates the gender distribution of secondary agriculture students in Missouri.
Sophomores, juniors, and seniors made up almost 85% of the sample. While this is
uncharacteristic of statewide enrollment figures, it is understandable given the selection criteria
for this study. Teachers were included based on their ability to incorporate a specific unit of
instruction into one of their courses. The unit most appropriately fit into an Ag Science II or
Natural Resources class. Each of these courses is typically regarded as upper level courses.
State reports for 2004 indicated the 40% of students state-wide were performing at or
above the nearing proficiency level on the MAP. Forty-four percent of the students in this study
were classified as nearing proficiency or higher. The MAP achievement levels imply that
students in agriculture courses are performing at least as well as the state-wide population of
students. As education continues to deal with accountability issues, it is reassuring that
agriculture students are performing as well as general populations. Future research is necessary
to investigate the contributions agriculture programs make toward standardized testing.
Mean scores for critical thinking indicate that some level of critical thinking is present in
secondary agriculture students. A lack of comparative information on secondary level critical
thinking ability makes interpreting the level inherently more challenging. Students in the study
scored considerably lower than normative date for various professions on the same form of the
WGCTA (Watson & Glaser, 1996). More information is needed for students at a similar grade
level.
Helmstadter (1985) criticized the WGCTA indicating that mean scores tend to progress
logically with age. Findings from this study indicated that an increase in grade classification
resulted in an increase in critical thinking ability. Upper grade-level students outperformed
lower grade-level students on critical thinking. In spite of Helmstadter’s concern, Rollins (1990)
Journal of Southern Agricultural Education Research 26
Volume 56, Number 1, 2006
study resulted in similar findings using a different measure of critical thinking. It is not clear
whether that increase is a result of education or a result of development.
Educators should continue to value the development of critical thinking. As teachers
strive to incorporate strategies into their classroom, differences among grade levels should be
considered. While findings from this study only indicate that differences may exist between
students at different grade levels, additional studies should be conducted to determine the extent
to which grade level impacts a student’s ability to think critically. Likewise, strategies most
effective for developing critical thinking should be identified through future research and
employed in agriculture programs.
There exists some disagreement in the literature regarding the influence of gender on
critical thinking. Rudd, Baker, and Hoover (2000) described gender as a significant variable in
critical thinking disposition. In contrast, current findings indicate males and females are similar
in their ability to think critically. This finding is consistent with research on college students
(Myers & Dyer, 2004). Possible differences in these findings may be a result in the inconsistent
descriptions and measures of critical thinking.
Findings indicate a moderate (Davis, 1971) relationship between achievement level and
critical thinking ability. Students categorized as higher academic achievement levels, as defined
by the MAP, exhibit higher critical thinking skills than those students categorized as lower
achievement levels. This relationship is in agreement with previous studies that have linked
measures of academic ability and critical thinking (Cano & Martinez, 1991, Ricketts & Rudd,
2005; Rollins, 1990).
A variety of definitions of critical thinking have been posed. While some call for
harmony or unity in our approach to critical thinking, perhaps the partitioning of critical thinking
as a construct is more appropriate. Contradictory findings related to critical thinking could be a
result of many sub-constructs. The relationship between academic achievement and critical
thinking may indicate that efforts to measure critical thinking may be really measuring academic
achievement. As definitions are continually refined, our instruments of measurement must be
refined as well.
Eighteen percent of the unique variance in critical thinking scores can be attributed to
achievement level category. Similarly, Rollins (1990) found that 28% of variance in critical
thinking, measured by the Cornell Critical Thinking Test, could be explained by score on the
Iowa Test of Education Development (ITED) reading subtest. Both findings support the
argument that academic performance is the best-known variable for explaining critical thinking.

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