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1.
<正> 用坐标图表示生物学现象和规律已屡见不鲜。通常,坐标图中 X 轴表示自变量,Y 轴表示因变量,所以坐标图中有两个变量。在高中阶段,依据《教学大纲》和《考试说明》的要求,在分析实验、设计实验时,通常要求的是单一变量(坐标图上为自变量)对结果的影响,其内容反映在坐标图上是清楚而简单的。但综观近年来的高考,在坐标图上出现3个甚至3个以上变量的问题时,就显得比较复杂且不易把握,所以 相似文献
2.
历年函数中考试题中涉及的知识点：一是平面直角坐标系中各象限和坐标轴上的点的坐标的特点,求点关于坐标轴、坐标原点的对称点的坐标,求线段的长度,几何图形的面积,求某些点的坐标等,主要考查考生对点的坐标等知识的理解及观察、分析的能力.二是求自变量的取值范围,求函数值、函数的图象、函数的表示方法,主要考查学生的判断能力、计算能力和作图能力等. 相似文献
3.
李树臣 《语数外学习(初中版)》2004,(12):34-35
知识点1．在实际应用中一次函数的图象可以是线段：2．通过函数图象，由自变量求因变量或由因变量求自变量的值；3．根据函数图象，通过“两点确定一条直线”求一次函数的表达式：4．通过一次函数的图象，求同一坐标系内两直线的交点坐标，并能根据实际问题的意义说明交点坐标的几何意义． 相似文献
4.
题型一 与函数有关的基础知识．包括坐标平面内点的坐标特征；各类函数的定义、图象、性质；函数自变量的取值范围等，对此类基础知识的考查．多以选择题、填空题的形式出现。通常是中考必考内容之一。 相似文献
5.
<正>一个二元一次方程组对应两个一次函数,也对应着两条直线,从"数"的角度上看,解方程组相当于考虑自变量为何值时两个函数值相等,以及这时函数值是多少;从"形"的角度上看,解方程组相当于确定两条直线的交点坐标 相似文献
6.
坐标图中X轴通常表示自变量,Y轴表示因变量,其内容反映在坐标图上只有一条曲线.但综观近年来的高考等生物试题,坐标曲线题型出现一些特殊的类型,这类试题信息隐蔽且丰富、区分度大,学生不易作答,因而有必要对这个问题进行归类分析. 相似文献
7.
考测点导航 1.点的坐标的定义及特殊点的坐标特征,点P(x,y)到原点及坐标轴的距离; 2.求函数自变量取值范围,确定简单实际问题的解析式; 3.特殊-一般-特殊、数形结合等数学思想方法。 相似文献
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9.
在物理实验和解题中,利用图像往往可以起到“化难为易、化否为能”的妙用．一般说来,两个物理量间的关系有很多都不是一次函数关系,若直接以这两个物理量为坐标,所画出的图像就不是直线,这样就无法根据图像找出两个物理量间的定量关系,也很难利用图像来解决实际问题．因此,在实验和解题中,如果两个物理量间的关系不是一次函数关系,我们就需要去寻找呈一次函数关系的自变量和因变量,再以这两个变量为坐标画图,将图像由曲线转变为直 相似文献
10.
本讲内容是中考中常考的考点，着重考查：关于x轴、y轴、原点的对称点的坐标问题以及求函数自变量的取值范围和确定简单实际问题的解析式等． 相似文献
11.
Comparing two types of model progression in an inquiry learning environment with modelling facilities 总被引：2，自引：0，他引：2
The educational advantages of inquiry learning environments that incorporate modelling facilities are often challenged by students’ poor inquiry skills. This study examined two types of model progression as means to compensate for these skill deficiencies. Model order progression (MOP), the predicted optimal variant, gradually increases the specificity of the relations between variables, whereas model elaboration progression (MEP) gradually expands the number of variables in the task. The study utilized a between-subject design with three conditions: a MOP condition (n = 28), a MEP condition (n = 26), and a control condition without model progression (n = 30). Consistent with expectations, model progression enhanced students’ task performance; a comparison among the two model progression conditions confirmed the predicted superiority of the MOP condition. These results are discussed in relation to the inconsistent findings from prior research. Based on this discussion ways to optimize model order progression are advanced. 相似文献
12.
This study examined whether and why assigning children to a segmented inquiry task makes their investigations more productive. Sixty-one upper elementary-school pupils engaged in a simulation-based inquiry assignment either received a multivariable inquiry task (n = 21), a segmented version of this task that addressed the variables in successive order (n = 21), or could formulate a task themselves (n = 19). Results showed that children are naturally inclined to pose single-variable inquiry questions. Segmented tasks, in addition, invoked more systematic but equally comprehensive investigations than a single, unsegmented task. More systematic experimentation was associated with more valid inferences and beliefs. These findings demonstrate that dividing a multivariable inquiry task into a series of single-variable subtasks facilitates the control of variables rather than the control of the learning process, and promotes inference performance and conceptual understanding. 相似文献
13.
Background
Previous studies used curriculum-based measurement (CBM) maze scores as an indicator of the reading comprehension level of secondary school students with and without special educational needs in multiple grades, pinpointing a high influence of both student- and context-related variables. However, studies on cumulative influence are necessary for better understanding of data-based decision-making.Methods
We examined a sample of 1066 secondary school students using four linear mixed-effect models: How much variance in maze scores exists between multiple student characteristics (i.e., gender, immigration background, learning disability and developmental language disorder) and context variables (i.e., classroom, grade and school type) across Grades 5–8?Results
The intra-class correlation (ICC) results show that the influence by the context-related variable classroom (ICC = .094) is almost as large as by the variable grade level (ICC = .126). School type (i.e., inclusive school vs. special school) has the least influence (ICC = .02). In addition, the effects of student-related variables explain only a small proportion of the variance (marginal R2 = .114).Conclusions
Maze scores can be used as a screening instrument for students with multiple characteristics across grades; they also show that it makes no difference which type of school students attend. As teachers and further classroom-related variables have almost as much influence as grade level, we discuss that teachers can minimise classroom effects by using maze scores as a formative approach. 相似文献14.
Characterising the relationship between participants’ scores on two different questionnaires is a common problem in educational research. The complement of the statistic known as Wilks’ Λ (lambda) measures the amount of variance shared between the scores obtained by the same group of participants on two sets of variables. (1 − Λ) is symmetric, in that it yields the same outcome whichever of the two sets is defined as the dependent variables. Other measures of shared variance have been proposed, but they are systematically conservative in comparison with (1 − Λ). In particular, measures of redundancy underestimate the proportion of shared variance because they fail to take into account the multivariate properties of the data. In short, (1 − Λ) can be commended for use as a measure of the strength of the association between the scores obtained on two questionnaires. 相似文献
15.
Visuomotor integration (VMI) is the ability to coordinate visual perception and motor functioning. Measures of VMI are commonly used to assess children's readiness for academic learning. Attention and investments towards VMI development are mainly focused on early learners, but some empirical research indicates sustained relations between VMI and academic achievement through middle and high school. To determine the relations between VMI and academic achievement, as well as moderating factors, we conducted a multilevel meta-analysis using a total of 96 articles and 266 effect sizes published over the past 60 years. The pooled effect size revealed moderate correlations between VMI and mathematical (r = 0.39) and reading (r = 0.34) achievement. Educational stage, disability, and intelligence were significant moderators of the relation between VMI and mathematics achievement, whereas educational stage and subdomains of reading skills were significant moderators of the relation between VMI and reading achievement. Implications and future research directions are discussed. 相似文献
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The authors examined how motivational and cognitive variables predict reading comprehension, and whether each predictor variable
adds unique explanatory power when statistically controlling for the others. Fourth-grade students (N = 205) completed measures of reading comprehension in September and December of the same year, and measures of background
knowledge and cognitive strategy use in December. Teachers rated internal reading motivation of each student. Results from
multiple regression analyses showed that motivation, background knowledge, and cognitive strategy-use made significant, independent
contributions to children’s reading comprehension when the other predictor variables were controlled. Further analyses showed
the same cognitive and motivational variables predicted growth over a 3-month period in reading comprehension. Possible explanations
of the observed relations between motivation, cognitive variables, and reading comprehension are presented. 相似文献
17.
Catharina Tibken Tobias Richter Nicole von der Linden Sandra Schmiedeler Wolfgang Schneider 《Child development》2022,93(1):117-133
Gifted underachievers perform worse in school than would be expected based on their high intelligence. Possible causes for underachievement are low motivational dispositions (need for cognition) and metacognitive competences. This study tested the interplay of these variables longitudinally with gifted and non-gifted students from Germany (N = 341, 137 females) in Grades 6 (M = 12.02 years at t1) and 8 (M = 14.07 years). Declarative and procedural metacognitive competences were assessed in the domain of reading comprehension. Path analyses showed incremental effects of procedural metacognition over and above intelligence on the development of school achievement in gifted students (β = .139). Moreover, declarative metacognition and need for cognition interactively predicted procedural metacognition (β = .169), which mediated their effect on school achievement. 相似文献
18.
Tracie O. Afifi Jonathan Boman William Fleisher Jitender Sareen 《Child abuse & neglect》2009,33(3):139-147
ObjectivesTo determine how the experiences of child abuse and parental divorce are related to long-term mental health outcomes using a nationally representative adult sample after adjusting for sociodemographic variables and parental psychopathology.MethodsData were drawn from the National Comorbidity Survey (NCS, n = 5,877; age 15–54 years; response rate 82.4%). Logistic regression models were used to determine the odds of experiencing lifetime psychiatric disorders and suicidal ideation and attempts.ResultsParental divorce alone was associated with some psychiatric disorders after adjusting for sociodemographic variables (AOR ranging from 1.30 to 2.37), while child abuse alone was associated with psychiatric disorders (AOR ranging from 1.39 to 6.07) and suicidal ideation (AOR = 2.08; 95% CI = 1.57–2.77) and attempts (AOR = 1.54; 95% CI = 1.02–2.31) after adjusting for sociodemographic variables. However, having experienced both parental divorce and child abuse together resulted in significantly increased odds for lifetime PTSD (AOR = 9.87; 95% CI = 6.69–14.55), conduct disorder (AOR = 4.01; 95% CI = 2.92–5.51) and suicide attempts (AOR = 2.74; 95% CI = 1.84–4.08) compared to having experienced either parental divorce or child abuse alone. These results were attenuated when further adjusting for parental psychopathology.ConclusionsWhen the experience of parental divorce is accompanied with child abuse, the associations with some poor mental health outcomes are significantly greater compared to the impact of either parental divorce or child abuse on its own. Therefore, parental divorce is an additional childhood adversity that significantly contributes to poor mental health outcomes especially when in combination with child abuse. Parental psychopathology attenuated these relationships suggesting that it may be one possible mechanism to explain the relationships between child abuse, parental divorce, and psychiatric disorders and suicide attempts. 相似文献
19.
Laura M. Steacy Ashley A. Edwards Jay G. Rueckl Yaacov Petscher Donald L. Compton 《Child development》2021,92(3):e252-e269
Developmental studies examining relations between word reading (WR) and decoding in typical and dyslexic populations routinely cut the reading distribution to form distinct groups. However, dichotomizing continuous variables to study development is problematic for multiple reasons. Instead, we modeled and visualized the parallel growth of WR and nonword reading (NWR) factor scores longitudinally in a Grade 1–4 developmental sample (N = 588). The results indicate that while WR and NWR growth factors are highly related (r = .71), the relation between WR and NWR trajectories change as a function of initial WR. Results are interpreted within computational models of dyslexia in which children with dyslexia overfit orthography → phonology relations at the level of the word, limiting the development of sublexical representations needed to read nonwords. 相似文献
20.
Philip J. Schluter Richard Audas Jesse Kokaua Brigid McNeill Barry Taylor Barry Milne Gail Gillon 《Child development》2020,91(1):e59-e76
Literacy success lays the foundation for children's later educational, health, and well-being outcomes. Thus, early identification of literacy need is vital. Using data from New Zealand's national preschool health screening program for fiscal years 2010/2011–2014/2015, demographic and health variables from 255,090 children aged 4 years were related to whether they received a literacy intervention in early primary school. Overall, 20,652 (8.1%) children received an intervention. Time-to-event analysis revealed that all considered variables were significantly related to literacy intervention (all p < .01), but the full model lacked reasonable predictive power for population screening purposes (Harrell's c-statistic = .624; 95% CI [.618, .629]). Including more direct literacy measures in the national screening program is likely needed for improvement. 相似文献