• Journal of The Korean Association For Science Education
• /
• v.25 no.2
• /
• pp.111-121
• /
• 2005

The purpose of this study was to analyze characteristics of experimental design and evidence choice of the elementary school students in problem solving process related to controlling variable. For this study, 96 6th grade students were selected and tested with Science Reasoning Task. This study revealed that the types of experimental design were categorized as variance of control variable, controlling of causal variable, perfect controlling variable, imperfect controlling variable, variance of all variable. Prior belief had a strong influence on student's experimental design. The types of evidence choice were categorized as perfect controlling variable, controlling causal variable, variance of causal variable. The degree of controlling variable in evidence choice process was much lower than that in experimental design. Most students tended to choose evidence according to prior belief without controlling variable. The results of this study implied that student's prior belief and characteristic of science process skills should be considered to develop program for promoting controlling variable ability.

• Journal of The Korean Association For Science Education
• /
• v.31 no.1
• /
• pp.32-47
• /
• 2011

The purpose of this study was to analyze the ability to control variables and the ways by which variables are controlled. First, the assessment criteria for evaluating the students' ability to control variables were developed for 8th grade students. Second, the ways variables are controlled were classified from student activity reports. These students' answers were categorized into six types (type A~ type F). Type A is defined as the group that excelled in recognizing the importance of controlling variables, eliminating unnecessary variables and identifying manipulated, dependent and controlled variables. Third, the scores of ability to control variables (CV score) and the classroom test of scientific reasoning (Lawson SRT) scores were measured. The results indicated that the CV score was highly correlated with Lawson SRT scores (r=.67, p<.01). Therefore, the assessment criteria developed in this study was used to evaluate the ability to control variables (CV score) and to measure the students' scientific reasoning.

• Journal of The Korean Association For Science Education
• /
• v.22 no.3
• /
• pp.571-585
• /
• 2002

This is one of the basic research for inspecting the possibility of the development of logical thinking capability to make possible formal thinking. The 5th grade students (n=306) in the elementary school were participated in this study. Performing the 6 variable-controlling activities in the 'Thinking Science' program for one semester, the SRT II test and the Variable-Controlling test were operated to examine the effects on the development of the variable-controlling ability by treatments, gender, and cognitive levels. Performing of the variable-controlling activities was highly successive on the development of students' variable-controlling ability. Although learning effect on the ability of identifying causal variable was moderate, the abilities of controlling experimental condition, measurement of variable, and identifying result variable were significantly developed. There was statistically significant difference by gender. Girls showed better performance all the time in both groups. Boys in the experimental group were getting better gradually, so the difference by gender was somewhat decreased. Examining the variable-controlling ability by cognitive levels, students in the experimental group show significant increase in all levels, especially the students in early, mid, and mature concrete level show substantial learning effects. The results of this study implied that the variable-controlling activities in the 'Thinking Science' could be effective for learning of variable-controlling and eventually for the development of logical thinking capability to make possible formal thinking.

• Journal of The Korean Association For Science Education
• /
• v.31 no.4
• /
• pp.587-599
• /
• 2011

The purpose of this study was to analyze variable-controlling strategy (below vcs) and the ability to infer the effect of variables in Middle school students who experienced 'Thinking Science' activities in a CASE program. For this study, 71 9th grade students experienced in CASE program for 2 years were selected as the experimental group and 72 students were selected as the control group. All students were tested with Science Reasoning TaskVII. The five types of variable-controlling strategy were extracted from students' response. According to the result of this study, the students experienced in CASE program was more successful in the variable-controlling strategy of length, quality, and shape than the control group. The types of reasoning ability of the variable effect intuitively were categorized as possibility of reasoning, impossibility of reasoning, and impossibility of reversible thinking. It has shown that the reasoning ability of the experimental group was higher than that of the control group in the length and thickness variable effect. The results of this study implied that the variable controlling activities in CASE program could be effective for learning variable controlling, and eventually, for the development of reasoning ability of the variable controlling effect. In the ability to infer the effects of variables to get difficult Intuitively, both groups were similar to the rate of cognitive level reached to the formal operation in generalization, and the student of experimental group was 1.5 times faster than the control group.

• Journal of the Korean Chemical Society
• /
• v.55 no.3
• /
• pp.519-528
• /
• 2011

The main purpose of this study was to develop a teaching program, especially designed to improve the skills of control variables. The secondary purpose was to investigate the effect of the program on enhancing students' scientific reasoning and understanding. The program was designed based on the 3-step learning model: i.e. students recognize the necessity of controlling the variables (step 1), perform their own experiments (step 2), and reflect on their variables control process (step 3). The program included 9 topics of increasing difficulty. In results, Lawson's SRT scores increased in both experimental and control groups after application of the program, but the difference was not statistically significant. After the application, there was an increase in type A and type B which implied that students' skills of control variables was improved. In addition, responses of students in the experimental group to the open-ended items showed that it was challenging for them to think scientifically and critically when controling variables, but they ended up feeling proud of their achievement after the program.

• Journal of Science Education
• /
• v.36 no.2
• /
• pp.251-262
• /
• 2012

In this study, we develop 15 learning programs to enhance the variable identification and control abilities for the middle school students and analyze the effect of the programs applied to the class. To increase the learning effect of the variable identification and control abilities, we design the programs so that the students can monitor their thinking processes and also they can evaluate the results from their cognitive activities objectively. We analyze the effect of the programs applied to the class and the results show that the test group, which uses the program, marks higher scores in the variable identification abilities compared to the control group. Also, the test group has the increased level of logic to control the variables. Especially, the effect is higher with the students who do not have any logic to control the variables. From the results, we know that it is possible to improve the variable identification and control abilities of the students through the meta-cognitive learning programs developed by us. Furthermore, the results show that the score of variable control abilities positively correlate with that of meta-cognitive level. It means that the meta-cognitive strategy meaningfully increases the variable control abilities of middle school students.

• Journal of the Korean earth science society
• /
• v.24 no.7
• /
• pp.604-613
• /
• 2003

The purpose of this study was to investigate the effect of a metastrategic activity on the development of student variable controlling abilities. Three groups of seventh graders at a middle-school in the City of Daegu participated in this study: a metastrategy activity group (ME), a problem-solving activity group (PR), and a control group (CO). The ME group was given metastrategy activity worksheets, which required students to monitor, control, and evaluate variable control strategies in a specified situation. The PR group was given problem-solving activity worksheets, which were needed to solve problems in various situations. The results were seen as follows. First, the metastrategy activity group showed better achievement (p<.05) and a longer standing effect (p<.01) than the other groups in the development of variable control ability. The problem-solving activity group was more effective than the control group (p<.05) in the development of variable controlled ability, but there was no lasting effect of the acquired ability. Second, the metastrategic activity group was more effective than the problem-solving activity group in finding fixed variables (p<.01), but not as effective in uncovering independent variables. What is not transferred to the development of the ability to find dependent variables.

• Journal of Families and Better Life
• /
• v.13 no.2
• /
• pp.11-21
• /
• 1995

본 연구는 도시 주부들의 가치.목표.표준과 가정관리목표달성의 정도를 측정하고 관련변인과 이들 변인들 간의 관계를 규명하고자 하였다. 연구대상은 서울시에 거주하는 433명의 주부를 대상으로 하였고 연구결과는 다음과 같다. 가정관리목표달성에 직접 영향을 미치는 변인은 목표설정, 수행표준, 자원제약, 운명통제지향 변인으로 나타났고, 자원제약과 운명통제지향은 목표설정과 수행표준을 매개로 한 간접효과도 있었다. 또한 학력, 가족수, 월평균 수입, 취업등의 변인들을 자원제약과 운명통제지향을 매개로 한 간접영향을 미쳤다.

• Journal of Families and Better Life
• /
• v.12 no.2
• /
• pp.195-204
• /
• 1994

본 연구는 주부의 내외통제성과 갈등관리방법에 영향을 미치는 사회인구학적 변인 및 내외통제성과 갈등관리방법간의 관계를 밝히는데 촛점을 두었다. 연구결과 첫째, 가족소득과 교육수준이 높을수록 내적통제성이 강한 것으로 나타났다. 둘째, 회피와 통제의 갈등관리 방법에 유의한 차이를 보인 변인은 없는 것으로 나타났고 조정관리방법은 연령에 따라 유의한 차이를 보였다. 셋째, 통제와 조정의 갈등관리방법은 내외통제성에 따른 차이가 나타나지 않았으나 회피의 갈등관리방법은 외적통제성향의 주부들이 사용하는 것으로 밝혀졌다.

• Journal of Nutrition and Health
• /
• v.53 no.2
• /
• pp.155-174
• /
• 2020

Purpose: The purpose of this study was to investigate the effects of nutrient intake and dietary diversity score (DDS) on osteoporosis after controlling for sex, age, socioeconomic level, drinking, smoking, physical activity, and body mass index (BMI) as mediators using the 2015-2017 Korean National Health and Nutrition Examination Survey (KNHANES) data. Methods: This study was focused on the age group of 50s and older by using the 2015-2017 KNHANES data. Subjects diagnosed with osteoporosis were classified as the osteoporosis group, and the other subjects were classified as the normal group. Logistic regression was used to assess the association between nutrient intake and DDS after controlling for mediators. Results: The risk of osteoporosis was 2.38 times lower in the 50-65 age group than in the 75 years and older group. The mediators affecting the incidence of osteoporosis by age group were sex, age, household income level, and education level in the 50-64 age group; sex, education level, drinking, and BMI in the 65-74 age group; and sex, age, current smoking, drinking, BMI, and energy intake in the 75 years and older group. The effect of nutrient intake on osteoporosis, with the exception of vitamin B1, was fully mediated by these mediators. The effect of vitamin B1 was partially mediated by mediators in the age group of 65-74 years, and vitamin B1 was effective for preventing the risk of osteoporosis by 25% when consumed over EAR. The effect of DDS was partially mediated in the age group of 75 years and older, and DDS of 2 or less increased the risk of osteoporosis by 2.59 times. Conclusion: As a result of this study, it is necessary to recommend the balanced intake of various foods including grains, meat·fish·legumes, vegetables, fruits, and dairy products as dietary guidelines for the prevention of osteoporosis and promotion of bone health in the elderly.